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A-0118Myelomeningocele as an anomaly of secondary neurulation
Ji Yeoun LEE1, Kyung Hyun KIM1, Eun Jung KOH1, Jeyul YANG2, Seung-Ki KIM1,
Kyu-Chang WANG1
1
2

Division Of Pediatric Neurosurgery, Seoul National University Hospital, Seoul, Korea, Republic of,
Department Of Neurosurgery, Myungji Hospital, Goyang, Korea, Republic of

Introduction : Myelomeningocele (MMC) is the representative entity of open neural tube defects
resulting from an error during primary neurulation. However, cases of MMC in the region of
the secondary neural tube (below the junction of S1 and S2 vertebral bodies) are sometimes
encountered. We aimed to analyze the clinical features of atypical ‘low-lying’ MMC and suggest
possible pathoembryogenesis.
Material & Methods : We defined ‘low-lying’ MMCs as those with fascia or lamina defects below theS1-2 interspinous ligament. A retrospective review of the radiological and clinical information was
performed.
Results : Thirty-one out of the 95 MMC patients were identified as having low-lying MMC. The
percentage of low-lying MMC within the entire MMC group increased dramatically (19% from 1990
to 1999 and 48% from 2000 to 2020). Thirty-nine percent of the low-lying MMCs were associatedwith hydrocephalus, and 36% of the Chiari malformations were associated with relatively small
proportions compared to the classic MMCs. Nine of the 12 patients with hydrocephalus underwent
ventriculoperitoneal shunting, and none with Chiari malformation required foramen magnum
decompression. Clean intermittent catheterization was being performed by 52% of the patients and
46% had a motor weakness.
Conclusions : We propose that open neural tube defect may be formed during secondary
neurulation as a result of 1) persistent connection between the primitive streak and the caudal cellmass or 2) rupture of the terminal balloon of the degenerating medullary cord. We present casesof atypical MMC occurring in the region of secondary neurulation. These cases provide clues that
secondary neurulation may lead to open neural defects.

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A-0133Is tethered cord release recommended to maintain or improve urinary tract
function in patients with myelomeningocele?
Tomomi KIMIWADA1, Toshiaki HAYASHI2, Hidenori ENDO3
1

Center For Pediatric Neurology & Neurosurgery, Shimane University Hospital, Izumo, Japan,
Department Of Neurosurgery, Miyagi Children’s Hospital, Sendai, Japan,
3
Department Of Neurosurgery, Tohoku University Graduate School Of Medicine, Sendai, Japan
2

Introduction : There is little evidence that tethered cord release (TCR) for tethered cord syndrome(TCS) can preserve or improve lower urinary tract function. Because the diagnosis of TCS is often
difficult, the rate of TCR has been shown to vary widely between centers. We retrospectively analyzed
the results of TCR based on urodynamic study (UDS) in children with myelomeningocele (MMC).
Material & Methods : Of 64 children who underwent MMC repair at Miyagi Children’s Hospital from2003 to 2016, 55 with more than 5 years of follow-up were included. Patient characteristics, risk
factors for TCS, surgical indications, and outcomes of TCR were evaluated.
Results : Mean follow-up was 11.5±3.5 years. Of the 55 patients, 27 TCRs were performed in 22
patients. The mean age at the time of each TCR was 7.0±2.7 years for the first TCR (n=22), 11.2
years for the second TCR (n=4), and 15.9 years for the third TCR (n=1). There were no risk factors
associated with TCS. Surgical indications for the first TCR were worsening lower extremity (LE)motor symptoms in one patient (4.5%), worsening LE sensory symptoms in two patients (9.1%), andworsening UDS findings in 22 patients (100%). Postoperatively, LE motor symptoms improved in one
patient (100%), LE sensory symptoms improved in one patient (50%), and VUDS findings improvedin 15 patients (68.2%), stabilized in six patients (27.3%), and worsened in one patient (4.5%). There
were no patients with either augmentation cystoplasty (AC) or renal dysfunction.
Conclusions : Urodynamically based TCR can prevent AC and renal dysfunction in MMC patients.

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A-0007
A case of thoracic meningomyelocele associated with mature teratoma
Keishi MAKINO1, Seiji TAJIRI1, Akira TAKADA1, Akitake MUKASA2
1

Neurosurgery, Kumamoto City Hospital, Kumamoto, Japan,
Neurosurgery, Kumamoto University, Kumamoto, Japan

2

Introduction : Meningomyeloceles are rarely associated with teratomas. Herein, we report a caseof mature teratoma diagnosed based on the pathological findings of a postoperative specimen
after meningomyelocele repair.
Material & Methods : The fetus was born by cesarean section under general anesthesia at 38 weeks
and 5 days of gestation. An opened spinal cord with a reddish protruding mass in a 6 × 5 cm skindefect was found in the midline of the back and lumbar region. Cranial magnetic resonance imaging(MRI) revealed enlarged lateral ventricles and Chiari malformation. Spinal MRI showed spinal cord
traction on the dorsal surface from the lower thoracic spine to the lumbar spine, with a cystic lesionon the rostral side, which was diagnosed as a myelomeningocele. Spinal computed tomography
showed spina bifida below the seventh thoracic vertebra.
Results : Myelomeningocele repair and CSF reservoir setting were performed. At the timeof myeloplasty, the protruding mass was resected and examined histologically. Histopathologicalexamination of the excised specimen revealed multilayered squamous epithelium, cartilage,
and vasculature as well as adenotubular structures and central nervous system tissue, which
led to the diagnosis of a mature teratoma. Based on these findings, the patient was diagnosed
with myelomeningocele associated with a spinal intramedullary mature teratoma. At 37 days ofage, ventriculoperitoneal shunting was performed. Spinal MRI on 10 months showed there were norecurrent findings.
Conclusions : Concurrence of mature teratomas with myelomeningocele is rare. As teratoma insidea myelomeningocele is a relatively benign neoplasm, the surgical approach to teratoma and removal
must be carefully considered.

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A-0083
Neural Tube Defects cases in an Indonesian Referral Hospital : A 5-Year
Epidemiological Study
Andi Nugraha SENDJAJA1, Yudhistira WARDHANA2, Gumar Jaya SALEH1
1

Neurosurgery, BP Batam Hospital, Batam, Indonesia,
Neurosurgery, Padjadjaran University, Bandung, Indonesia

2

Introduction : Neural tube defects (NTDs) are the congenital malformations in humans affecting
the development of the central nervous system that significantly increase the risk of death anddisability in the 1st year of life. This retrospective study aimed to potray NTD cases based on the dataobtained from one of the Indonesian referral hospital in the Riau Islands in hopes of providing useful
information through epidemiological data.
Material & Methods : We retrospectively examined the demographic features, familial risk factors,
physical examination, radiological findings, accompanying diseases and surgical managements of
27 patients with NTDs from Badan Pengusahaan Hospital Batam, Indonesia from January 2019 up to
August 2023.
Results : Of the 27 patients hospitalized in a 5year period were male - dominated (55.5%). The
median birth weight was 2800 g and the median delivery week was 37 weeks. 7 of the patients(26%) had meningomyelocele, 17 patients (63%) had posterior encephalocele, and 3 patients (11%)
had anterior encephalocele. 11 of the patients (40.7%) had Congenital Hydrocephalus. 22% of themothers had a history of periconceptional use of folic acid. The median time of making a diagnosis of
NTD by prenatal ultrasonography was 20 (16–24) weeks. 7 of the patients (26.6%) had other organ
disorders, some with multiple systemic disorders.
Conclusions : Based on the study, we revealed that our NTDs cases the majority affect malepatients, with posterior encephalocele as the most common cause and just 22 percents of themothers had a history of periconceptional use of folic acid.

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A-0103
Terminal Myelocystocele cases, personal experience in Northokkalapa General
Hospital, Myanmar and Ibaraki Children’s Hospital, Japan. Aye Mya Phyu, Kyi
Hlaing, Takayuki Inagaki Northokkalapa General Hospital and Ibaraki Children’s
Hospital
Aye MYA PHYU1, Takayuki INAGAKI1, Kyi HLAING1
1

Neurosurgery, Northokkalapa General Hospital, University Of Medicine 2, Yangon, Mtanmar, Yangon,
MyanmarIntroduction : Terminal myelocystocele is a rare and discrete spinal cord abnormally. It constitutes
4—8% of spinal dysraphism.TMC are cystic dilations of low lying extraspinal terminal cord covered
with adipose tissue and intact skin. It can also constitutes spinal subarachnoid expansion,
meningocele and hydromyelic cord. We discuss about surgical management and embryology based
upon two cases of isolated terminal myelocystocele.
Material & Methods : Case1.Six month old boy presented with congenital lumbosacral swelling which
increase in size with time.MRI shows fluid filled cystic mass without apparent nervous tissue which
is typical appearance of terminal TMC. Case 2: One month old boy was presented with 3×4 cm
intergluteal cleft swelling with hemangiomatous navi since birth. He was neurologically normal atdiagnosis. MRI show terminal cyst with tethered cord into extra spinal compartment at dorsal side
and covered by subcutaneous tissue and skin.
Results : Untethering and myleocystocele repair was done in both patients. There were no post
operative CSF leak and other complications. No motor deficits was seen in both patients. Urinary
incontienence was seen in one patient.
Conclusions : Since the report of TMC by McLone and Naidich, several reports were published.
We presented two cases of TMC cases based upon first author’s personal experience, here. These
two cases are not associated with other anomalies. It is thought that TMC cases should be surgicaltreated at a few months old, since some patients of TMC may have severe tethered spinal cord andmost of them are surgically treatable compared to complex lipomyelomeningocele.

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A-0163Time Window for Neurosurgical Management of Currarino Syndrome: Case
Illustration
Shih Hsiang KING1, Chih-Ju CHANG1, Meng-Fai KUO2
1

Division Of Neurosurgery, Department Of Surgery, Cathay General Hospital, Taipei, Taiwan, 2Division Of
Neurosurgery, Department Of Surgery, National Taiwan University Hospital, National Taiwan University
College Of Medicine, Taipei, Taiwan

Introduction : The Currarino syndrome is defined by the triad of anorectal malformations, sacral bone
deformities, and presacral masses. It is frequently associated with neuroanatomical anomalies. A
complex combined anterior and posterior approach was suggested in some literature. Nevertheless,little is known of the neurosurgical attitude.
Material & Methods : A newborn girl of Currarino syndrome presented with constipation and a
protruding mass out of her anus. Anal tube was used to facilitate the defecation. When the patientcame to us at the age of 2 months, the anal mass has withdrawal into the rectum spontaneously
and she was free of anal tube using. Based on this important history, neurosurgical intervention was
postponed and undertaken at age of 7 months when MRI showed clear anatomical structure.
Results : During surgery, the filum terminale were tethered by an abnormal enlargement of neuroglial
tissue and lipoma. Complete detethering was achieved. A space ventral to the transected caudal
stump extended ventrally into the pelvic space. Continuous suture between the ventral dura and thecaudal stump was made to obliterate the space. A favorable surgical outcome was achieved after a
28-month follow-up. An anterior surgical approach was not undertaken due to the asymptomatic andstationary presacral mass.
Conclusions : Neurosurgical management of Currarino syndrome may be wisely postponed till
the surgical anatomy is favorable for a complete untethering and a secure dural repair if there is nopotential risk of severe complications like recurrent meningitis, pyomyelia, or severe neurologicaldeficits.

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A-0178
Occurrence and related treatment of Tethered cord in children with Anorectal
malformation
Qingshuang ZHAO1, Junjie JING1
1

Neurosurgery, Fujian Children’s Hospital, Fuzhou, China

Introduction : This research reviewed children with anorectal malformation (ARM) complicated withcongenital Tethered Cord Syndrome (TCS) to explore the incidence of ARM children with TCS and thesignificance of related treatment.
Material & Methods : Medical history and imaging data of 105 children with ARM from February
2018 to February 2022 were reviewed. According to the MRI results, the children were divided into
TCS group and non-TCS group, and the relationship between TCS and ARM type and whether
Tethered cord lysis could improve defecation function.
Results : All 105 children with ARM were classified into two groups according to the Wingspreadclassification. 36 cases were assigned to the intermediate and high risk group, while 69 cases wereassigned to the low risk group. The difference between the two groups was statistically significant .
Among TCS group, 2/29 cases with poor defecation function, 2 cases with good function, 11 caseswith excellent function, and 14 cases with normal function. Among the 76 children in the non-TCS
group, there were 3 cases with poor defecation function, 4 cases with good function, 23 cases withexcellent function, and 46 cases with normal function. There was no significant difference between
the two groups (P=0.244).
Conclusions : The incidence rate of middle and high ARM combined with TCS is high, and theincidence of TCS of all pathological types is similar, without statistical significance. It is suggested
that routine lumbosacral MRI should be performed in children with ARMs to detect TCS.

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A-0096
Prevention of retethering in untethering surgery of a tight filum terminale
Hideki OGIWARA1
1

Neurosurgery, National Center For Child Health And Development, Tokyo, Japan

Introduction : Retethering after Untethering surgery for a tight filum terminalehas been reported tooccur. One of the major mechanisms is adherence of the cut end of the sectioned filum to the midline
dorsal dural surface. In order to prevent retethering, we sectioned a filum terminale at the rostral levelto the dural incision so as to keep the distance between the cut end of the sectioned filum and thedural incision. We investigated whether this procedure decreased the occurrence of retethering.
Material & Methods : Among the cases between 2012 and 2016, and followed up more than 5 years
were included. Symptoms, preoperative imaging, surgical details, perioperative complications, andoutcomes were reviewed retrospectively.
Results : A total of 342 cases were included. The median age at surgery was 11 months.
Preoperative magnetic resonance imaging (MRI) revealed 255 cases had low set conus. There were
142 cases with filar lipoma and 42 cases. Syringomyelia was found in 29 patients. Two hundreds
forty-six caseswere symptomatic and 96 cases were asymptomatic. The median postoperative
follow-up was 88 months. There were 4 cases (1.2%) with retethering presented with bladder andbowel dysfunctions. The mean time from initial untethering to retethering was 54 months. All 4 cases
underwent untethering surgery, and preoperative symptoms resolved in 3 patients.
Conclusions : The retethering rate after untethering surgery for a tight filum terminale in our series
was lower than those of the previous reports. Sectioning the filum terminale at the rostral level to thedural incision was considered to be an effective way for prevention of retethering.

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A-0095The optimal timing to record the baseline of intraoperative bulbocavernosus
reflex monitoring
Maya KONO1, Yuta FUJIWARA1, Masae KUROHA1, Mami YAMASHITA1, Satoshi IHARA1
1

Neurosurgery, Tokyo Metropolitan Children’s Medical Center, Tokyo, Japan

Introduction : Intraoperative bulbocavernosus reflex (BCR) monitoring is useful for untethering
surgery in children. The baseline BCR amplitude was recorded around dural incision in someprevious reports, but the other reports did not mention the timing of recording the baseline. The aimof this study is to clarify the optimal timing to record the baseline of intraoperative BCR monitoring.
Material & Methods : Patients performed untethering surgeries between January 2021 to March 2023
were included. Patients with extradural lesion such as spinal lipoma were excluded. We reviewed
patients’ medical chart and analyzed retrospectively. Primary outcome was more than 50 % decreaseof BCR amplitude at dural incision. The first segment (R1) of BCR waveforms was evaluated for
intraoperative BCR monitoring in this study.
Results : There were total 113 untethering surgeries. 5 patients experienced bilateral BCR decrease(4.4%). The existence of urological symptom was significantly higher in decrease group. There were226 BCR waveforms from 113 patients. 24 BCR was decreased at dural incision. BCR amplitude atregistration was significantly higher in decrease group than not-decrease group.
Conclusions : Among tethered cord syndrome, the traction of spinal cord is believed to cause
its hypoxia and nerve damage. The existence of urological symptoms before untethering surgery
indicates nerve damage. BCR might be susceptible to decrease regardless of surgical procedures.
The BCR amplitude at registration can be used as a baseline amplitude among most of patients. If
the patient experienced urological symptoms before untethering surgery, the BCR amplitude justbefore dura was opened might be better to use as a baseline amplitude.

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A-0136
Image overlay surgery attempt of spinal dysraphism
Miiko ITO1, Yukihiko SONODA1
1

Neurosurgery, Yamagata University Faculty Of Medicine, Yamagata, Japan

Introduction : In spine surgery, confirmation the level of spinal cord is important. However, incases with severe deformity, the merkmal on the surface are deviated and the usefulness of theintraoperative support system is reduced. In recent years, there has been demanded for minimallyinvasive surgery, especially in the abdominal surgery. On the other hand, complications due todisorientation are concerned. Therefore, image overlay surgery (IOS), which projects a threedimensional(3D) image onto the body surface, has been used and its utility has been reported.
Material & Methods : A 12year-old girl. She underwent repair of terminal myelocystocele.
Subsequently, scoliosis progressed and was considered an indication for spinal fusion so thatpreventive untethering was decided. The skeleton was significantly deformed, and there wereconcerns about disorientation. But various intraoperative image support such as navigation was
difficult, so we tried IOS projects 3D images directly onto the body surface. After induction ofanesthesia, identify the palpable spinous processes of the cervical and upper thoracic vertebrae,
confirm the spinous processes of the cervical and upper thoracic vertebrae with fluoroscopy, 3D-CT
images are displayed using a projector. The lumbosacral vertebrae were identified by projecting it on
the back and aligning it with the merkmar.
Results : Intraoperative findings revealed no discrepancies between the IOS projection image andthe actual structure, and spinal cord untethering was performed.
Conclusions : We applied IOS to surgical procedure of spinal dysraphism with severe deformity, andit was very useful to confirm the level of spinal cord.

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A-0193
Human Tail with Tethered Cord Management: Experience in Two Cases
Nadya ZARAGITA1, Kevin GUNAWAN1, Samsul ASHARI1
1

Neurosurgery, Universitas Indonesia, Jakarta, Indonesia

Introduction : Human tail is rare cutaneous lesion which is associated with occult spina bifida. It
may be accompanied with tethered cord, but the tail itself may not always be the cause of tethering.
Its appearance is extremely infrequent, making reports meaningful to study their variations anddetermine the management.
Material & Methods : Authors report two cases of of vestigial tail with tethering based on MRI studies.
Fat tissue was found to be attached to the radix, connected to the tail. Patients underwent surgicalprocedure to untether the spinal cord and excise the fat tissues without the use of IOM. Untetheringand removal of the tail was done safely. Patient did not have any new neurological deficits post
operatively.
Results : Human tail may be a sign of congenital anomalies surrounding the lesion which also require
surgical treatment. Surgical management of human tail is not only for the sake to achieve good
cosmetics, but also to treat other related anomalies, in this case tethered cord. Authors proposed that
IOM is not always required as no neural structure within the tail should be preserved and fat tissue
attached to the spinal cord or radix can be reduced safely before dural closure.
Conclusions : It is important to note that human tail may be a sign of occult spinal dysraphism.
Understanding the underlying anatomy through imaging studies is critical prior surgical procedures.
When structures appear to be separable based on the studies, IOM is not always necessary. Thus,
surgical procedure of human tail can be safely done even in limited settings.

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A-0173
Two cases of vanishing cerebellum associated with myelomeningocele
Kazuaki SHIMOJI1, Kouichiro SAKAMOT2, Kou1 HORIKOSHI2
1
2

Neurosurgery, International University Of Health And Welfare, Chiba Prefecture, Japan,
Neurosurgery, Juntendo University School Of Medicine, Tokyo, Japan

Introduction : Chiari type 2 malformation (CM2) is a common finding associated withmyelomeningocele(MMC). However, it is uncommon to observe symptoms such as apnea justafter birth. It seems to be rare but if there is a severe transforaminal herniation, this will results in a“degeneration” of cerebellar tissue called “vanishing cerebellum”(VC). We had a chance to treat twocases of MMC associated with VC which followed a different course compared to common MMCs.
Material & Methods : Representative case This baby girl was diagnosed hydrocephalus due to
MMC in an ultrasound. She was intubated at the OR because of a respiratory disorder after birth.
Primary closure and an Ommaya reservoir insertion was performed at the same day. She frequently
shown apneic episodes. Usually decompression surgery is planed if the symptoms were due toCM2 however the cerebellar tissue was invisible except some remnant tissue. A tracheostomy was
performed at day 89. She underwent VP shunt. Her respiratory problems are still remaining duringfollow up.
Results : There is another pathology which is called cerebellar agenesis. Compared to this condition,a small posterior fossa and the remnant cerebellar tissue is seen in VC which leads to an idea that
this phenomenon is associated with damage of cerebellum due to CM2.
Conclusions : When VC is associated with MMC, the patient has a risk to develop respiratory
problems in early age which the course is different with common cases. If this condition is seen inprenatal imaging, intrauterine repair may not be an option and careful treatment is necessary.

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A-0060Appropriate Use of Different Surgical Approaches and Surgical Outcomes in
Hemispherotomy
Takehiro UDA1, Noritsugu KUNIHIRO2, Vich YINDEEDEJ1, Toshiyuki KAWASHIMA1,
Yuta TANOUE1, Ryoko UMABA2, Takeo GOTO1
1

Neurosurgery, Osaka Metropolitan University Graduate School Of Medicine, Osaka, Japan,
Pediatric Neurosurgery, Osaka City General Hospital, Osaka, Japan

2

Introduction : Hemispherotomy, a curative surgery for hemispheric epilepsy, has developed basedon lateral approach. Subsequently, vertical approach was introduced. Both approaches involve
disconnection of the corpus callosum, projection fibers and limbic system of one hemisphere, but thesurgical maneuvers are quite different. The selection of surgical approach is determined dependingon patients’ characteristics or institutions. Here, we present the selection criteria for the surgicalapproach at our institution, with presenting some surgeries, and report the postoperative courses.
Material & Methods : We retrospectively reviewed our patients who underwent hemispherotomy fromFebruary 2015 to June 2023. Basically, vertical approach was selected. Lateral approach was applied
when the brain structures including the interhemispheric fissure were deviated and intraoperativeorientation might be poor, when the lateral approach was supposed to be easier due to severely
atrophic or destructive hemisphere, or when a wide craniotomy was made. The completeness ofhemispherotomy, surgical complications, and seizure outcome were evaluated.
Results : Twenty-one patients were included in the analysis. Age at surgery ranged from 0 to 38
years. Seventeen patients were applied vertical approach and 4 patients were applied lateralapproach. In one patient with vertical approach, hemispherotomy was incomplete with requiring
reoperation. The other 20 patients, hemispherotomy was completed by either approachs. Threepatients required additional surgical intervention due to hydrocephalus, but no other complications
were observed. Fifteen patients achieved seizure free after surgery.
Conclusions : Hemispherotomy can be completed with appropriate approach selection and step-bystep fiber dissection. The complication rate is low except for hydrocephalus and the seizure free rate
is high.

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A-0005
Quantitative differences in triggered electromyography during selective dorsal
rhizotomy in children with spastic cerebral palsy of different motor functions
Wenbin JIANG1, Bo XIAO1
1

Neurosurgery, Shanghai Children’s Hospital, Shanghai, China,
Neurosurgery, Shanghai Children’s Medical Center, Shanghai, China

2Introduction : To investigate the electromyography (EMG) responses of dorsal nerves with varying
current intensity during Selective Dorsal Rhizotomy (SDR) and to compare the response differencesin children with spastic cerebral palsy and with different motor functions.
Material & Methods : The trigger-EMG patterns of dorsal nerves during SDR were reviewed. The
current intensity that could first evoke a 200 μV EMG amplitude in one of the monitored muscles was
defined as Threshold-200, and we further defined Threshold-100 and Threshold-25 as the current
intensity that could first evoke a 100 μV or 25 μV EMG amplitude in one of the monitored channels.
The trigger-EMG patterns under the three thresholds were quantitatively analyzed to determine theconsistency of the most innervated channel (largest EMG amplitude) and the spreading of triggerEMG patterns under different stimulus strengths.
Results : The study included 185 dorsal nerve roots from 12 patients, with 5 classified as the mildgroup (Gross Motor Function Classification System levels 1-2) and 7 as the severe group (Gross
Motor Function Classification System levels 3-4). The consistency of the most innervated channel at
the three thresholds was 49.2% among all patients. The severe group had higher consistency thanthe mild group (56.6% vs. 38.7%, P<0.05). The spreading of trigger-EMG patterns under all three
thresholds was greater in the severe group than in the mild group.
Conclusions : The study found that the patterns of trigger-EMG in spastic cerebral palsy with different
motor functions are different. A quantitative and in-depth study of intraoperative electrophysiological
data during SDR surgery is of great clinical significance.

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A-0135Predicting Efficacy of Vagal Nerve Stimulation (VNS) Surgery among MedicallyRefractory Paediatric Epilepsy Patients in Hospital Tunku Azizah (HTA): A
Cohort Observational StudyNUR NAZLEEN SAID MOGUTHAM1, AZMI ALIAS1, AHMAD RITHAUDDIN MOHAMED1,ABDUL RAHMAN IZAINI GHANI2, FADZLISHAH JOHANABAS ROSLI1
1

Neurosurgery, Hospital Kuala Lumpur, Kuala Lumpur, Malaysia, SELANGOR, Malaysia,
School Of Neurosciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia

2

Introduction : Vagus Nerve Stimulation (VNS) surgery has increasingly been considered atherapeutic approach for children with drug resistant epilepsy (DRE). Question is, who benefits the
most? We describe a one-centre experience of VNS implantation in paediatric patients with DRE to
investigate efficacy and potential predictive factors.
Material & Methods : 28 patients who underwent surgery from 2018 to 2021 were followed up for 18
months. Primary outcome measure was reduction in seizure frequency. Secondary outcome measure
is post-operative outcome (McHugh classification) plus improvement in seizure severity. Third
outcome is measurement of quality of life (QoL) of patient and carer.
Results : Seizure frequency was reduced by more than 50% in 44.7% of patient at 6 months and57.1% at 18 months. There was improvement of seizure severity and with regards to seizure outcome,23 patients that had earlier VNS implantation (< 5 years old) had good outcome; Class II and III
McHugh classification).Out of 10 predictive factors investigated, age at seizure onset (≥ 3 years old)
(p=0.008) and age at VNS implantation (< 5 years old) (p=0.035) were correlated with responders(p< 0.05) in univariate and multivariate analysis. Lastly, there is improvement in patient QoL score(p<0.001) and reduction in caregiver stress score(p<0.001).
Conclusions : VNS implantation has shown overall seizure reduction over 18 months at our centre.
Younger age at implantation (< 5 years) and seizure onset age > 3 years old are two predictors offavourable clinical outcome in patients with epileptic encephalopathy. Lastly, there is improvement of
QoL for both patient and carer after surgery.

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A-0011
Finger movement functions remain in the ipsilesional hemisphere andcompensation by the contralesional hemisphere might not be expected after
hemispherotomy -pre- and post-hemispherotomy evaluations in 8 casesAyataka FUJIMOTO1, Ryuya HOTTA1, Shingo NUMOTO1
1

Comprehensive Epilepsy Center, Seirei Hamamatsu General Hospital, Hamamatsu, Japan

Introduction : We hypothesized that fine finger motor functions are controlled by the ipsilesional
hemisphere, and that gross motor functions are compensated for by the contralesional hemisphere
after brain injury in humans. The purpose of this study was to compare finger movements before andafter hemispherotomy that defunctionated the ipsilesional hemisphere for patients with hemisphericallesions.
Material & Methods : We statistically compared Brunnstrom stage of the fingers, arm (upper
extremity), and leg (lower extremity) before and after hemispherotomy. Inclusion criteria for this study
were: 1) hemispherotomy for hemispherical epilepsy; 2) a ≥6-month history of hemiparesis; 3) postoperative follow-up ≥6 months; 4) complete freedom from seizures without aura; and 5) application of
our protocol for hemispherotomy.
Results : Among 36 patients who underwent multi-lobe disconnection surgeries, 8 patients (2 girls,
6 boys) met the study criteria. Mean age at surgery was 6.38 years (range, 2–12 years; median, 6years; standard deviation, 3.5 years). Paresis of the fingers was significantly exacerbated (p = 0.011)
compared to pre-operatively, whereas that of the upper limbs (p = 0.07) and lower limbs (p = 0.103)
was not.
Conclusions : Finger movement functions tend to remain in the ipsilesional hemisphere after
brain injury, whereas gross motor movement functions such as those of the arms and legs arecompensated for by the contralesional hemisphere in humans. This content has been accepted andpublished in Brain & Development107

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Oral presentation 11 : EPILEPSY 1

A-0012
Safety, accuracy and efficacy of robot-assisted stereo-electroencephalography
in children of different ages
RUI ZHAO1
1

Department Of Neurosurgery, Children’s Hospital Of Shanghai, Shanghai, China

I n t r o d u c t i o n : To e x p l o r e t h e s a f e t y, a c c u r a c y a n d e f f i c a c y o f r o b o t - a s s i s t e dstereoelectroencephalography in children of different ages.
Material & Methods : Patients were divided into 3 groups according to age at the time of robotassisted SEEG procedures, group 1: ≤ 3 years of age (n=28), group 2:3-6 years of age (n=27),
and group 3: >6 years of age (n=44). Clinical data, SEEG demographics, target point error (TPE)and entry point error (EPE), complications and seizure outcome were gathered for analysis. Seizure
outcome was evaluated according to Engel’s classification.
Results : A total of 675 electrodes were implanted, with a mean number of 6.8 ± 3.474 (2−16)
electrodes implanted per patient. The mean age at SEEG was 84.1±52.404 months (8.0-205.0
months). The mean skull thickness was 4.1±1.461mm (1.6-10.4mm). There were no significant
differences for the number of electrodes (P=0.052). The mean operation time of each electrode was
9.8 mins ± 1.291 mins (6.0–11.7 mins) in total patients. The average TPE and EPE of 675 electrodes
were 1.93 mm ± 1.106 mm (range, 0.00–8.56 mm) and 1.30 ± 0.9738 mm (range, 0.00–9.54mm). There were no significant differences for TPE and EPE (P=0. 536 and P=0. 549). The overall
complication rate was 5.05%. There were no significant differences for complications in the threegroups(P=0.587). No severe or long‐term neurologic impairment existed in all patients. Clinicaloutcome was not statistically different among the three groups(p=0.191).
Conclusions : Robot-assisted SEEG is an effective and safe invasive approach. There is no
significant difference in its safety, effectiveness and implantation error among children of different age
groups.

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Oral presentation 11: EPILEPSY 1

A-0079
Merit of Endoscopic Posterior Approach for Total Callosotomy
Vich YINDEEDEJ1, Takehiro UDA1, Toshiyuki KAWASHIMA1, Yuta TANOUE1, Satoru SAKUMA2,
Emiko MORIMOTO3, Takeo GOTO1
1

Neurosurgery, Osaka Metropolitan University, Osaka, Japan,
Pediatrics, Osaka Metropolitan University, Osaka, Japan,
3
Radiology, Osaka City General Hospital, Osaka, Japan
2

Introduction : Endoscopic surgery is now getting popular among epilepsy surgeons. Our recent
study reported that endoscopic corpus callosotomy (CC) requires smaller craniotomy and skinincision without increasing operative time and post-operative complications compared withconventional microscopic CC. However, an anterior approach to the corpus callosum, which is
generally applied in total CC, usually needs interhemispheric arachnoid dissection at the cingulate
gyri. It is sometimes difficult and could take a long time. On the other hand, a posterior approach tothe corpus callosum needs less interhemispheric arachnoid dissection, or even none, because of theclose anatomical relationship between corpus callosum and the falx cerebri.
Material & Methods : We presented a patient of 5-year-old girl with medically intractable epileptic
spasms. Endoscopic total CC with posterior approach was performed to control her seizures.
Results : The patient was placed in the prone position and a 6-cm linear skin incision was performed.
A craniotomy was made crossing the midline and the dura was opened. Endoscope was introducedwith gentle retraction of the brain. The arachnoid of the interhemispheric fissure did not need tobe dissected to reach the splenium of the corpus callosum. CC was started from the splenium
and continued anteriorly until reaching the rostrum of corpus callosum. Total CC was performed
completely. Post-operative status went well. Completeness of total CC was confirmed by MRI. She
has achieved considerably seizure reduction.
Conclusions : We achieved endoscopic total CC via posterior approach without any complications.
This technique appears more feasible as a less-invasive surgery because of the unnecessity ofinterhemispheric arachnoid dissection.

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Oral presentation 11: EPILEPSY 1

A-0086Detection of absence seizures using a glasses-type eye tracker
Takumi MITSUHASHI1, Hidenori SUGANO1, Akihide KONDO1, Eishi ASANO1
1
Department Of Neurosurgery / Epilepsy Center, Juntendo University, Tokyo, Japan, 2Department Of
Pediatrics, Children’s Hospital Of Michigan, Detroit Medical Center, Wayne State University, Detroit, UnitedStatesIntroduction : Epileptic seizures, including absence seizures, are often associated with a sustained
upward deviation of the eyes. This methodological study tested the feasibility of using a mobile
glasses-type eye tracker for detecting absence seizure events.
Material & Methods : A seven-year-old boy with childhood absence epilepsy simultaneously
underwent eye-tracking and video-electroencephalography (EEG) monitoring. We determined how
accurately and rapidly the sustained upward eye deviation observed by the eye tracker would detect
the electrographic onset of absence seizure events marked by two board-certified epileptologists.
Results : The video-EEG captured nine absence seizure events. The eye tracker detected eight outof the nine seizure events with a mean delay of 2.87 seconds from the electrographic onset without afalse alarm. It failed to detect an absence seizure event exhibiting a minimal clinical change on video.
Conclusions : This study demonstrated the eye tracker’s feasibility for seizure detection for the firsttime to our best knowledge. Further studies of larger numbers of patients are warranted to determine
if eye-trackers can provide useful complementary information to other detection methods and serve
as a viable wearable seizure detection device at home.

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Oral presentation 11: EPILEPSY 1

A-0015
Short-term change of tibial torsion in children with spastic cerebral palsy after
selective dorsal rhizotomy
Rui WANG1, Wenbin JIANG1, Min WEI1, Junlu WANG1, Xidan YU2, Bo XIAO3, Qijia ZHAN1
1

Neurosurgery, Children‘s Hopspital Of Shanghai, Shanghai, China,
Rehabilitation, Pubin Children’s Hospital, Shanghai, China,
3
Neurosurgery, Shanghai Children’s Medical Center, Shanghai, China
2Introduction : This retrospective study examined the effects of selective dorsal rhizotomy (SDR) on
tibial torsion in children with spastic cerebral palsy (CP). Tibial torsion, a common condition in thesechildren, affects lower limb morphology and motor function.
Material & Methods : The study included 148 children with spastic CP who underwent SDR at
Shanghai Children’s Hospital. Pre- and post-operative assessments measured joint range of motion,transmalleolar angle (TMA), muscle tone, and motor function.
Results : SDR resulted in decreased muscle tone and increased joint range of motion in the lower
limbs. Bilateral TMA significantly increased after surgery. Before SDR, 86.8% of limbs had internal
tibial torsion, 11.8% were normal, and 1.4% had external tibial torsion. Limbs with internal tibial
torsion were more common in older patients and had higher muscle tone in the tibialis anterior andsoleus muscles. Among limbs with internal tibial torsion, 21.0% normalized after SDR. One limb withexternal tibial torsion also normalized. Limbs that improved after SDR belonged to younger patientsand had lower muscle tone in the hamstring muscles.
Conclusions : Older age and higher spasticity in the tibialis anterior and soleus muscles increase
the risk of internal tibial torsion. SDR shows promise in improving tibial torsion in children with spastic
CP. Limbs classified as internal tibial torsion are more likely to improve after SDR if they have lower
muscle tone in the hamstring muscles and belong to younger patients.

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Oral presentation 12: EPILEPSY 2

A-0020
CLINICAL OUTCOME OF EPILEPSY SURGERY OF THE TEMPORAL LOBE IN
PEDIATRIC GROUP : A RETROSPECTIVE COHORT STUDYKHAIRUN MISPAN4
1

NEUROSURGERY, HOSPITAL RAJA PERMAISURI BAINUN, IPOH, Malaysia,
NEUROSURGERY, HOSPITAL KUALA LUMPUR, KUALA LUMPUR, Malaysia,
3
NEUROSURGERY, HOSPITAL TUNKU AZIZAH, KUALA LUMPUR, Malaysia,
4
NEUROSCIENCE, HOSPITAL UNIVERSITI SAINS MALAYSIA, KUBANG KERIAN KELANTAN, Malaysia
2

Introduction : All pediatric patients who underwent temporal lobe lobectomy or lesionectomy for
epilepsy surgery at Hospital Kuala Lumpur were reviewed. All operations were done by a single
senior consultant neurosurgeon at Hospital Kuala Lumpur.
Material & Methods : This study was a retrospective cohort study over a period of 8 years from
1st January 2012 until 1st July 2019. Engel Outcome Classification was used to identify seizure
outcome at immediate, 3-6 months and one year post operation. Age, sex, age of seizure onset,
age of operation, body weight, number of antiepileptic medications pre and post operation,
duration of stay in ICU and ward, MRI and histopathological findings and complications were noted.
Analytically, Fisher Exact test was used for categorical data. Wilcoxon Signed rank test was used forcontinuous but not normally distributed data.
Results : 29 pediatric patients met study criteria. The Mean time between seizure onset and surgery
was 5.6 years. Outcome Classification, Engel 1 Outcome or Seizure Free was achieved in 28 patients(96.6%) at immediate follow up, 24 patients (82.8%) at 3-6 months follow up and 24 (82.8%) at
1-year follow up. Hippocampal Sclerosis was present in 13 patients (44.8%). Tumours were present
in 16 patients (55.2%). The complication proportion was 14.4%. Only 2 (6.9%) patients underwent
reoperations. There is significant changes in post operative Anti Epileptic Medications (AEDs)
reduction in this study (P= 0.006).
Conclusions : The surgery outcome of epilepsy surgery of the temporal lobe in pediatric group was
remarkable in this study. Careful patients’ selection by multidisciplinary evaluations is mandatory.

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Oral presentation 12: EPILEPSY 2

A-0035Long-term Outcome of Resective Epilepsy Surgery in Patients With LennoxGastaut Syndrome
Dong-Seok KIM1
1

Severance Children’s Hospital, Yonsei University, Seoul, Korea, Republic of

Introduction : We aimed to evaluate the long-term outcome of resective epilepsy surgery in patientswith Lennox-Gastaut syndrome (LGS).
Material & Methods : We reviewed the case reports of 90 patients with LGS who had undergone
resective surgery between 2003 and 2014 at the Severance Children’s Hospital and managed themfor a minimum period of 2 years.
Results : At the time of surgery, the patients were between 3.0 and 23.5 years old (mean ± SD:
9.3 ± 4.4). The time from seizure onset to surgery ranged from 0.7 to 20.1 years (7.2 ± 4.3). On
postoperative follow-up for an average period of 6.1 ± 2.2 years (range: 2.1–11.4 years), 45 patients(50.0%) had no seizures, and 15 (16.7%) reported infrequent seizures. Seizure-free outcomes wereachieved in 15 of the 21 (71.4%) hemispherectomies, 23 of the 51 (45.1%) multilobar resections,and 7 of the 18 (38.9%) single lobar resections. On highresolution MRIs, 20 patients (22.2%) had
negative findings, 8 of whom (40.0%) became seizure-free after resective surgery. Malformation ofcortical development was the most common pathologic finding and was noted in 57 patients (63.3%).
Seizure-free patients achieved better adaptive behavior and social competence than did patientswith persistent seizures at the second (2–3 years after surgery) and third (4–6 years after surgery)followups, as indicated by social quotients (P < .05).
Conclusions : Resective surgery is a viable option in some patients to treat seizures that areassociated with LGS, with a high probability of seizure control and better adaptive function.

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Oral presentation 12: EPILEPSY 2

A-0090Proper therapy selection improves epilepsy outcomes in patients withmultilobar Sturge–Weber syndrome
Hidenori SUGANO1, Hiroharu SUZUKI1, Takumi MITSUHASHI1, Yasushi IIMURA1
1

Neurosurgery, Juntendo University, Tokyo, Japan

Introduction : Hemispherectomy is an optimal treatment for patients with Sturge-Weber syndrome(SWS) affecting the whole hemisphere; however, a consensus has not been reached regarding
therapeutic choices for those with involvement of two to three lobes. In this study, we comparedseizure and cognitive outcomes between antiepileptic drugs and surgical treatment groups inpatients with multilobar involvement.
Material & Methods : We evaluated 50 patients (aged ≥6 years) with multilobar (2–3 lobes)
involvement. Surgical indications included 1) antiepileptic drug (AED)-resistant seizures, 2)developmental delay, and 3) cortical atrophy. Twenty-nine patients were classified in the medical
treatment group (MTG) and 21 patients were in the surgical treatment group (STG). Seizure typeand frequency, SWS electroencephalography score (SWS-EEGS), and pre- and post-therapeutic
SWS neurological scores (SWS-NS) were compared between groups. Median ages at the initial
evaluation of the MTG and STG were 4 and 2 years, and at the final evaluation were 13 and 17 years,
respectively.
Results : The STG had a higher incidence (76.2%) of focal to bilateral tonic-clonic seizures andstatus epilepticus, although no difference in SWS-EEGS. Seizure and cognitive subcategories of
SWS-NS at initial evaluation were worse in the STG (p=0.025 and p=0.007). The seizure subcategory
in MTG and STG improved after therapy (p=0.002 and p=0.001, respectively). Cognition wasmaintained in MTG and improved in STG (p=0.002). The seizure-free rates in MTG and STG were
58.6% and 85.7%, respectively.
Conclusions : Appropriate therapeutic choices improved seizure outcomes. Although patients who
required surgery had more severe epilepsy and cognitive impairment, surgery improved both.

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Oral presentation 12: EPILEPSY 2

A-0134
Epilepsy Surgery Outcome for Long-term Epilepsy-Associated Tumors (LEATs)
Hsin-Hung CHEN1
1
Division Of Pediatric Neurosurgery, The Neurological Institute, Taipei Veterans General Hospital, Taipei,
TaiwanIntroduction : Brain tumors represent the second most frequent etiology in patients with focal seizure
submitted to epilepsy surgery. To review the clinical and neurophysiologic features and surgicaloutcome in our patients with intractable tumoral epilepsy, LEAT: low-grade epilepsy-associated(neuroepithelial) tumors, low-grade, developmental, epilepsy-associated brain tumors.
Material & Methods : Patients with drug-resistant epilepsy who underwent resection of brain tumors,confirmed by surgical pathology, seen between 2010/12 and 2023/5 at Taipei Veterans General
Hospital were selected. Medical records were reviewed for age at diagnosis, age at onset of seizures,
delay between seizure onset and tumor diagnosis, types and frequencies of seizures, EEG results,
use of anticonvulsants, extent of surgery, and pathologic diagnosis.
Results : Patients with drug-resistant epilepsy who underwent resection of brain tumors, confirmedby surgical pathology, seen between 2010/12 and 2023/5 at Taipei Veterans General Hospital wereselected. Medical records were reviewed for age at diagnosis, age at onset of seizures, delay
between seizure onset and tumor diagnosis, types and frequencies of seizures, EEG results, use of
anticonvulsants, extent of surgery, and pathologic diagnosis.
Conclusions : Long-term follow-up of patients with intractable tumoral epilepsy in children suggests
good response of seizures to surgery, which is unrelated to age at diagnosis, EEG, or pathology.
Extent of tumor resection was significantly predictive of outcome, whereas early intervention showed
better quality of life with higher possibility of discontinued anticonvulsants.

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Oral presentation 12: EPILEPSY 2

A-0144R E S U LT S O F T R E AT M E N T O F I N T R A C TA B L E E P I L E P S Y W I T H
HEMISPHEROTOMY SURGERY AT VIETNAM NATIONAL HOSPITAL OF
PEDIATRICS
Le NAM THANG1
1

Neurosurgery Department, National Hospital Of Pediatrics - Viet Nam, Hanoi, Vietnam

Introduction : Overview: Intractable epilepsy is a common clinical problem and makes treatment
difficult. In patients with intractableepilepsy whose diagnostic investigations involve diffuse unilateralhemispheric involvement, hemispherotomy surgery is a good option for improved treatment and isbecoming more common. At Vietnam National Hospital of Pediatrics, which has been performing
the hemispherotomy surgery since 2016;so we retrospectively evaluated the surgical outcome in thegroup of children who were performed the functional hemispherotomy at Vietnam National Hospital of
Pediatrics for the purpose of evaluating the outcome of surgical treatment.
Material & Methods : Methods: A retrospective study was performed on a group of 12 pediatricpatients who underwent hemispherotomy from 2016 to 2022. We collected patients’ information
through medical records, radiography imaging pre- and post-surgery and re-examination of thepatients to evaluate the outcome.
Results : Results: Regarding gender, the ratio of male/female patients = 10/2; Mean age at surgery:
3.9±3.3 years old (9 months-10 years old); mean duration of epilepsy prior to surgery: 2.62 ± 2.29
years (8 months – 7.5 years); the group of seizure onset from neonatal accounts for the highest
rate: 50%; preoperative diagnosis: hemimegalencephaly 58.3%, Rasmussen’s encephalitis 16.7%,
secondary hemiatrophy16.7%, and 1 case of negative magnetic resonance; 2 surgical techniques
were performed were vertical hemispherotomy: 41.7%, peri-insular hemispherotomy: 58.3%; outcomeof surgery: Engel I: 50%, Engel II: 50%.
Conclusions : Conclusion: Hemispherotomy surgery at Vietnam National Hospital of Pediatrics
initially brought good results in seizure control in the treatment of intractable epilepsy.

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Oral presentation 12: EPILEPSY 2

A-0150Characteristics of the “Super Responders” to Vagus Nerve Stimulation in
Pediatric Intractable Epilepsy
Goichiro TAMURA1, William LO3, Kerry VAUGHAN2, Cristina GO4, William SINGLETON2,David HAZON2, Ivanna YAU4, Han YAN2, Yosuke MASUDA1, Eiichi ISHIKAWA1, Hiroshi OTSUBO4,
Elizabeth DONNER4, James RUTKA2, George IBRAHIM2
1

Department Of Neurosurgery, University Of Tsukuba Hospital, Tsukuba, Ibaraki, Japan, 2Division Of
Pediatric Neurosurgery, Department Of Surgery, The Hospital For Sick Children, Toronto, Ontario, Canada,
3
Department Of Neurosurgery, Birmingham Children’s Hospital, Birmingham, United Kingdom, 4Division Of
Neurology, Department Of Pediatrics, The Hospital For Sick Children, Toronto, Ontario, Canada

Introduction : Vagus nerve stimulation (VNS) therapy is an important part of the multimodal treatment
of intractable epilepsy in children. However, clinical responses to VNS therapy are unpredictable.
A better understanding of the characteristics of good and poor responders to VNS in the pediatricpopulation is critical to improve patient selection and response prediction.
Material & Methods : We attempted to identify distinctive features of the subset of children
who become seizure free following VNS implantation, defined as “super-responders” (SRs). We
investigated their clinical features with the aim of elucidating response-predictive factors in children
with intractable epilepsy. Retrospective data were collected from 150 children who underwent VNS ata single pediatric institution.
Results : The patients’ mean age at VNS device implantation was 12.0 years (3.09–17.9 years).
Ten SRs (6.7%) were identified who achieved and maintained seizure freedom for longer than 1
year following implantation. The interval between epilepsy onset and VNS device implantation was
significantly shorter in SRs than in the other children (mean epilepsy duration 5.72 vs. 8.44 years,
respectively; p=0.032). SRs reported their seizure freedom relatively early (six patients within 6months and all patients within 12 months after implantation) at relatively low device settings (meanoutput current 0.81mA at their last follow-up). Compared with conventional models, responsive VNS
models with autostimulation features did not increase the ratio of SRs. No other clinical or imaging
characteristic difference between SRs and the other children was found in this cohort.
Conclusions : The current study showed a significant association between shorter epilepsy durationand seizure freedom after VNS.

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Oral presentation 12: EPILEPSY 2

A-0198Hemispherectomy at less than 8 months of age contributes to earlier acquisitionof language and motor functions
YASUSHI IIMURA1
1

Neurosurgery, Juntendo University, Tokyo, Japan

Introduction : Hemispherectomy is indicated for refractory epilepsy with unilateral hemisphericepileptogenicity. Although early hemispherectomy promotes subsequent psychomotor development,a clear timeline for language and motor function development remains unknown. In addition totesting the hypothesis that early hemispherectomy is beneficial to neural development, this study also
determined the age at which linguistic and motor functions develop after hemispherectomy.
Material & Methods : The inclusion criteria were as follows: 1) age < 15 years at hemispherectomy;2) inability to speak any meaningful words or stand by themselves without help; 3) complete cessationof seizures after hemispherectomy; 4) at least 1-year follow-up postoperatively. Finally, 33 patients
who met the inclusion criteria were classified into the following groups: 1) age at surgery: ≤8 months(≤8MO, n=18) and ≥9 months (≥9MO, n=15) and 2) left (n=18) and right (n=15) groups according
to surgical side. Correlation analysis was performed between age at surgery (A Surg) and the age at
which children’s speech evolved to single word articulation (AWord), sentence construction (ASentence),
independent standing (AStand), and independent walking (AWalk).
Results : Significant linear correlations were observed between A Surg and AWord (p=0.032),
ASentence (p=0.018), AStand(p<0.0001), and AWalk (p<0.0001). Spearman’s correlation coefficients were0.430, 0.478, 0.716, and 0.722, respectively. In the ≤8MO group, language and motor function
acquisition was significantly earlier than in the ≥9MO group.
Conclusions : A significant correlation was found between early surgery and the time of acquisitionof neural function. This study demonstrated that early hemispherectomy promotes early neuraldevelopment in patients with intractable hemispheric epilepsy.

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Oral presentation 13: ARACHNOID CYST

A-0053
Arachnoid cyst presenting psychotic disorders in pediatric population: caseseries and systemic literature review
Peng-Chan HUANG1, Muh-Lii LIANG1
1

Neurosurgery, Mackay Memorial Hospital, Taipei City, Taiwan

Introduction : Arachnoid cysts in pediatric population are the most common intracranial cysts andtheir role in causing psychotic disorders is often underrecognized. However, the appearance of somereferences that focus on a possible link between arachnoid cysts and psychotic symptoms raisedquestions about the etiologies and the therapeutic approach involved.
Material & Methods : Between January 2020 and July 2023, 39 children, diagnosed with arachnoid
cysts at MacKay Children’s Hospital were enrolled and the representative symptoms including
psychotic disorders were evaluated retrospectively. 19 out of 39 patients underwent cystocisternostomy or endoscopic fenestration.
Results : The clinical characteristics of the study were 26 male and 13 female patients. The mean
age is 5.6 years of age, ranging from 2 weeks to 15 years old at diagnosis. The presenting symptoms
included psychosis (7), precocious puberty (6), headache (4), seizure (4) and visual loss (1). The
others (15) were asymptomatic. In seven patients with psychotic symptoms, four arachnoid cysts
located in sylvian fissure, two retrocerebellar region, and one intraventricularly in which two patientswith sylvian arachnoid cysts underwent cysto-cisternostomy and one with retrocerebellar cyst
underwent endoscopic fenestration. During the mean 12-month follow-up, all three patients withpsychotic disorders obtained improvement after cyst decompression.
Conclusions : Psychiatric symptoms are not usually an indication for neurosurgical intervention.
However, it is demonstrated that mental symptoms account for a certain proportion of patients witharachnoid cysts in the study, and the subjective improved mental functions were not unusual after
cyst decompression. Further prospective studies will help to understand the relationship between
psychiatric symptoms and arachnoid cysts.

1194th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Oral presentation 13: ARACHNOID CYST

A-0115Absence of membranous obstruction in the posterior fossa for pediatric blake’s
pouch cyst with hydrocephalus
Yutong LIU1, Gao ZENG1, Peng SUN1, Mading ZHOU1
1

Neurosurgery, Xuanwu Hospital Beijing Capital University, Beijing, China

Introduction : Blake’s pouch cyst (BPC) is considered a congenital disease related to the failure of
perforation of posterior membranous area (PMA) to form Magendie’s foramen. However, the existenceof the cystic structure in the posterior fossa and the relationship between BPC and hydrocephalus
remain controversial.
Material & Methods : We retrospectively analyze 13 pediatric BPC cases that underwent surgery forhydrocephalus at the Di Rocco Center of Pediatric Neurosurgery in Xuanwu Hospital.
Results : All patients underwent surgery due to hydrocephalus. The mean age of surgery was
1.34±1.07 years. A filiform structure in the posterior fossa was visible in magnetic resonanceimaging in 69.2% of cases. Cerebrospinal fluid (CSF) flow studies were conducted for 9 patients,
supporting an unobstructed CSF flow at the foramen magnum. Direct inspection of the ‘cyst’
was performed in 2 cases using a flexible ventriculoscope and in 1 case through open surgery.
No evidence of obstruction was observed. Regarding treatment modalities, 8 patients received
endoscopic third ventriculostomy (ETV), and one underwent posterior fossa exploration. However,
all of them experienced failure and subsequently underwent ventriculoperitoneal shunt (VPS). The
pulsation of the orifice after ETV was not strong in 75% of ETV cases, indicating minimal pressure
difference of cerebrospinal fluid above and below the Liliequist membrane.
Conclusions : There is no evidence of membranous obstruction at the foramen magnum in postnatal
pediatric BPC cases. The membranous structure may exist, but only for a short period of time during
fetal development. The mechanism of hydrocephalus in BPC might initiate with obstruction but
ultimately transition to a communicating factor.

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Oral presentation 13: ARACHNOID CYST

A-0018Prepontine arachnoid cyst in an 8-month-old infant presenting with third andfourth cranial nerve palsy
William WINARDI1, Yi-Wen CHEN2, Pei-Ling WU2, Kuo-Wei WANG3
1

Neurosurgery, E-Da Hospital, Kaohsiung, Taiwan, 2Pediatrics, E-Da Hospital, Kaohsiung, Taiwan,
Neurosurgery, E-Da Cancer Hospital, Kaohsiung, Taiwan

3

Introduction : The incidence of intracranial arachnoid cysts in children is approximately 2.6%, witha slight male predominance. Small arachnoid cysts may be asymptomatic, but some patients may
present with symptoms resulting from their mass effect. We present an 8-month-old patient with aprepontine arachnoid cyst presenting with ptosis, inability to look down and in, with a rare ipsilateralhead tilt. These presentations are consistent with left third and fourth cranial nerve palsies.
Material & Methods : A pterional craniotomy was performed, and the sphenoid ridge was flattened tofacilitate access to the skull base. The dura was opened in an inverse-U fashion. Under an operating
microscope, a trans-Sylvian fissure route was utilized to approach the cystic lesion. Cyst fenestration
was performed and released clear cystic fluid to allow further examination of skull base structures.
Intradural left internal carotid artery, left middle cerebral artery, and left optic nerve were identified.
Unfortunately, the cystic membrane bled easily, and therefore we stopped pursuing the visualizationof other cranial nerves.
Results : The patient was successfully extubated within hours after surgery. Ptosis, extraocular
movement, and head tilt were immediately improved. The patient’s postoperative course was smooth,and was discharged on postoperative day 8.
Conclusions : Symptomatic intracranial arachnoid cysts should be treated immediately to prevent
further neurological deficits. Our patient’s clinical presentation of ptosis, inability to look down and in,
and ipsilateral head tilt are consistent with third and fourth cranial nerve palsies. An ipsilateral headtilt should not exclude fourth nerve palsy, as this is a rarer compensatory mechanism.

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Oral presentation 13: ARACHNOID CYST

A-0027
Expanding ventricular diverticulum overlying the cerebral hemisphere throughan open-lip schizencephalic cleft: a presentation of two pediatric cases
Nobuya MURAKAMI1, Ai KUROGI1, Tadahisa SHONO2, Takafumi SHIMOGAWA3,
Nobutaka MUKAE3, Takato MORIOKA4, Koji YOSIHMOTO3
1

Neurosurgery, Fukuoka Children’s Hospital, Fukuoka, Japan,
Neurosurgery, Harasanshin Hospital, Fukuoka, Japan,
3
Neurosurgery, Graduate School Of Medical Sciences, Kyushu University, Fukuoka, Japan,
4
Neurosurgery, Hachisuga Hospital, Fukuoka, Japan
2

Introduction : Open-lip-type schizencephaly is characterized by trans-cerebral clefts filled withcerebrospinal fluid (CSF) between the subarachnoid space at the hemisphere surface and the lateral
ventricles. Disorders related to CSF retention, including hydrocephalus and arachnoid cysts, havereportedly been associated with open-lip schizencephaly and have induced intracranial hypertension
in some cases. However, detailed neuroimaging and surgical treatment findings have rarely been
described.
Material & Methods : We present two pediatric cases of open-lip schizencephaly with an expanding
CSF-filled cavity overlying the ipsilateral cerebral hemisphere that manifested as signs of intracranial
hypertension.
Results : Detailed three-dimensional heavily T2-weighted imaging revealed thin borders between
the CSF-filled cavity and the subarachnoid space but no separating structures between the cavity
and the lateral ventricle, suggesting that the cavity was directly connected to the lateral ventricle
through the schizencephalic cleft but not to the subarachnoid space. Neuroendoscopic observationof the CSF-filled cavity in Case 1 confirmed this finding. Endoscopic fenestration of the cavity to the
prepontine cistern was ineffective in Case 1. Shunting between the lateral ventricle (Case 1) or CSFfilled cavity (Case 2) and the peritoneal cavity slightly decreased the size of the CSF-filled cavity.
Conclusions : We speculate that the thin borders along the margin of the CSF-filled cavity aremembranes that previously covered the schizencephalic cleft and are now pushed peripherally.
In addition, we speculate that the cavity is a ventricular diverticulum protruding through the cleft.
Detailed magnetic resonance imaging can be useful for evaluating patients with schizencephaly
associated with CSF retention disorders.

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Oral presentation 13: ARACHNOID CYST

A-0031
Endoscopic Treatment for Symptomatic Suprasellar Arachnoid Cysts inChildren; A Single Center Experience
Shirabe MATSUMOTO2, Shinji IWATA1, Akari KUSAKAWA1, Toshimoto SENO1,
Haruhisa ICHIKAWA1, Keiichi SHIBAGAKI1, Satoshi FUJIWARA1, Koji FURUKAWA1,
Shinji ONOUE1, Shiro OHUE1
1
2

Neurosurgery, Ehime Prefectural Central Hospital, Matsuyama City, Japan,
Neurosurgery, Ehime University Graduate School Of Medicine, Toon City, Japan

Introduction : Endoscopic ventriculo-cysto-cisternostomy (VCC) is considered to be effective method
for suprasellar arachnoid cyst (SAC). The purpose of this report is the experience of symptomatic
SACs that were successfully treated endoscopically in our institution.
Material & Methods : Between 2019 and 2022, endoscopic treatment was performed on 3 cases ofSACs. 3 female patients ranged in age from 9 months to 8 years. Follow-up of the patients ranged
from 1 year to 3 years.
Results : The clinical signs and symptoms observed were hydrocephalus in 2 cases, developmental
delay in 2 cases, and visual field defect in 1 case. All 3 patients were treated by VCC connecting thecyst with the third ventricle and pre-pontine cistern, and had no perioperative complications. In all
3 patients showed improvement in postoperative clinical findings, and there were no recurrences orretreatments during the follow-up period.
Conclusions : The medium-term prognosis of all patients who underwent VCC was good. Amongendoscopic treatment for SACs, VCC performed in our institution is reported to have less recurrence
than ventriculo-cystostomy. We have to evaluate long-term follow-up outcomes.

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Oral presentation 13: ARACHNOID CYST

A-0040An infantile case of symptomatic cerebellopontine angle arachnoid cyst treatedwith microsurgical fenestration.
Kodai UEMATSU1, Tatsuya KURODA1
1

Neurosurgery, Gifu Prefectural General Medical Center, Gifu, Japan

Introduction : Surgical fenestration is indicated for symptomatic infantile arachnoid cyst. We reportan infantile case of symptomatic right cerebellopontine angle arachnoid cyst treated with direct
fenestration.
Material & Methods : An eight-month-old boy suffering from hearing impairment was referred to our
hospital. Head MRI showed right cerebellopontine angle arachnoid cyst. He also had right abducens
nerve palsy, so we planned surgical treatment.
Results : Microsurgical fenestration with a lateral suboccipital approach was performed. The dorsal
and ventral sides of the arachnoid cyst were opened as much as possible. The endoscope was
kept on standby during the operation, but was not used in the end. The postoperative course wasuneventful, and he was discharged from the hospital on the 9th postoperative day. After the operation,
sound response and abducens nerve palsy were improved, and the ABR also showed a shortened
latency.
Conclusions : There are some reports that both endoscopic fenestration and microsurgicalfenestration have good results for pediatric cerebellopontine angle arachnoid cyst. It was considered
important to select a surgical method, based on the size of the cyst, the positional relationshipbetween the cranial nerves and the cyst, the surgical experience of the surgeon, etc.

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Oral presentation 13: ARACHNOID CYST

A-0071
Surgical treatment of a rare case of lateral thoracic meningocele.
Kazuki AKUTAGAWA1, Ai MUROI1, Takao TSURUBUCHI1, Eiichi ISHIKAWA1
1

Neurosurgery, University Of Tsukuba Hospital, Ibaraki, Japan, Japan

Introduction : Lateral meningocele is a rare congenital malformation classified as a closed neuraltube defect. We present an unusual case of lateral thoracic meningocele associated with right upper
limb hypoplasia.
Material & Methods : Case presentation: A boy aged one year and four months with congenital
right upper limb hypoplasia was admitted to our department. Postnatal magnetic resonance imaging(MRI) demonstrated a right lateral meningocele associated with myeloschisis at the C7 to Th6 level.
The meningocele was located in the subclavian space and compressed the right brachial plexus,
resulting in upper limb hypoplasia. Due to developmental delay, the patient underwent untetheringand meningocele repair.
Results : The surgery was performed under neurophysiological monitoring. The dural sac was
exposed on the midline, and the dura was incised. The fibrous band extending from the bifid spinal
cord to the wall of the meningocele was detached. The meningocele wall was separated fromthe normal dural sac, and the dura was tightly sutured. On postoperative MRI, the meningocele
disappeared, and the patient could walk independently four months after the surgery and defecate at
the age of three. During seven years of follow-up, no symptoms developed.
Conclusions : Thoracic meningocele is an uncommon entity that is difficult to treat surgically. Whensymptomatic, a careful radiological examination and a multidisciplinary approach are required.

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A-0149Surgical Treatment and Developmental Evaluation in Primary Interhemispheric
Arachnoid Cysts with Dysgenesis of the Corpus Callosum
Tae Kyun KIM1, Joo Hwan KIM1, Seung-Ki KIM1, Ji Yeoun LEE1, Kyung Hyun KIM1, Ji Hoon PHI1
1

Neurosurgery, Nara Medical University Hospital, Kashihara,Nara, Japan,
Pediatric Neurosurgery, Seoul National University Children’s Hospital, Seoul, Korea, Republic of2

Introduction : Interhemispheric arachnoid cysts (IHACs) in children are rare lesions which often
associate with corpus callosum dysgenesis. It is still controversial about surgical treatments to IHACs.
Our aim is to report our experience of pediatric IHAC patients and evaluate surgical courses andneurological developments.
Material & Methods : Pediatric IHACs treated between 2001 to 2021 were reviewed retrospectively.
IHAC was observed until it represented neurological symptoms. Cyst fenestration was done bymicroscope or endoscope depending on the IHAC`s location. Cyst size and corpus callosum
dysgenesis was evaluated with neuroimaging. Neurological development was evaluated from medical
records at the last follow-up.
Results : Fifteen children received cyst fenestration surgery (mean age 11.4 months). Elevenpatients (73.3%) who were under observation showed rapid cyst enlargement in a short period(median 5 months). Cysto-venriculostomy (CVS) and cysto-cisternostomy (CCS) regressed the cyst
size significantly (p=0.003). Median follow-up duration was 51 months (range 14-178 months). Elevenpatients had corpus callosum dysgenesis (complete=5, partial=6) which seven patients (63.6%)
represented some degree of developmental delay, including four patients with speech delay.
Conclusions : Symptomatic IHACs frequently present within one year after birth, with rapid cyst
enlargement. CVS and CCS was effective to regress the cyst size. Corpus callosum dysgenesis
accompanied with IHAC might have a risk of language achievement, however, development delay
could rely on multifactorial features, such as epilepsy and other brain anomalies.

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A-0034
Management of First Recurrence or Progression of Craniopharyngioma
After Resection Alone in the Pediatric Population: A Systematic Review andIndividual-Participant Data Meta-Analysis
Yilong ZHENG1, Shi Hui ONG1, Balamurugan VELLAYAPPAN2, Vincent NGA3
1

Yong Loo Lin School Of Medicine, National University Of Singapore, Singapore, Singapore,
Radiation Oncology, National University Hospital, Singapore, Singapore,3
Neurosurgery, National University Hospital, Singapore, Singapore
2Introduction : It is generally accepted that the initial management of pediatric craniopharyngioma
should be either gross total resection (GTR) or subtotal resection (STR) with radiotherapy (RT).
However, the optimal management strategy for recurrent/progressive craniopharyngioma remains
unclear. Hence, we aimed to compare the outcomes of surgery and/or RT for the first recurrence/progression of craniopharyngioma after resection alone in the pediatric population.
Material & Methods : PubMed and Embase were systematically reviewed for studies that reported
individual-participant data on outcomes after surgery and/or RT for the first recurrence/progressionof craniopharyngioma after resection alone in patients aged <18 years old at treatment for the
first recurrence/progression. The exposure was the treatment that was administered for the firstrecurrence/progression, and the outcomes were tumor regrowth and overall survival (OS).
Results : Of the 2932 studies screened, 7 studies reporting 51 patients were included in the metaanalysis. The commonest treatment for the first recurrence/progression was RT alone (n=16, 31.4%),
followed by STR with adjuvant RT (n=14, 27.5%), STR alone (n=11, 21.6%), GTR alone (n=7, 13.7%),
and GTR with adjuvant RT (n=3, 5.9%). STR alone for the first recurrence/progression was associatedwith a significantly higher risk of tumor regrowth (p=0.015), while the rest of the treatment arms had
an equally low risk of tumor regrowth. There was no significant association between the treatment
arms and OS (p=0.760).
Conclusions : In pediatric patients with the first recurrence or progression of craniopharyngioma
after resection alone, STR alone should be avoided if feasible in favor of GTR alone or RT with orwithout surgery, for improved local control.

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A-0043The utility of prone flexion MRI after filum terminale transection surgery
Ryuji ISHIZAKI1, Yasunori NAGAI1
1

Neurosurgery, Shizuoka Children’s Hospital, Shizuoka, Japan

Introduction : The assessment of retethering after filum terminale transection surgery is primarily
conducted through MRI. However, in supine position, the cut end of the terminal filament often shifts
towards the dorsal side, making evaluation challenging. Since MRI in the prone flexed position is now
possible due to devices of MRI imaging methods, we investigated the evaluation of retethering after
filum terminale transection surgery by comparing the supine and the prone positions.
Material & Methods : The distance from the dorsal dura mater of the rostral end of the filum terminale
after filum terminale transection surgery was measured in 33 patients evaluated by supine, prone,
and prone flexion MRI at our hospital from October 2018 to January 2023.
Results : The mean age at filum terminale transection surgery was 9 years and 11 months (6 years
0 month - 17 years 6 months), and the mean age at MRI examination was 1 year and 10 months (7days - 10 years 0 month). The distance (mm) from the dorsal surface of the dura mater was 0 mm in
33 patients (100%) in the supine position, 27 (82%) in the prone position, and 15 (45%) in the prone
flexion position. If 2 mm or more was considered untethering, 0 (0%) patients in the supine position, 3(9%) patients in the prone position and 18 (55%) patients in the prone flexion position were 2 mm or
more.
Conclusions : Prone flexion position MRI appeared to be more useful than prone position MRI in theevaluation of retethering after filum terminale transection surgery.

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A-0188
Validation of the Kitea implantable ICP monitoring system in a chronic sheep
modelPeter HEPPNER1, Sang Ho KIM2, Sarah-Jane GUILD2, Abdel-Hamed DABBOUR2,
Natalia LOPEZ3, Bryon WRIGHT3, Robert GALLICHAN3, Dixon LEUNG3, Daniel MACCORMICK2,
Masahiro KONDO3, Simon MALPAS2
1

Paediatric Neurosurgery, Starship Childrens Hospital, Auckland, New Zealand,
Biomedical Engineering, University Of Auckland, Auckland, New Zealand,
3
Kitea Health Ltd, Kitea Health Ltd, Auckland, New Zealand2

Introduction : Detecting shunt malfunction is potentially costly and inconvenient for patients,
requiring hospitallisation and radiological imaging. The Kitea micro implant is designed to allow longterm home monitoring of ICP with an inductively charged device. We aimed to determine efficacy ofthe device in a long term large animal study.
Material & Methods : 10 sheep had Kitea ICP implants placed alongside ventricular catheters.
After recovery from surgery the animals were transferred to a farm. Here they underwent weekly ICP
recordings utilising a wireless wand over a 6 month period.
Results : ICP recordings were able to be obtained at every attempt. Over the 6 months theserecordings remained in the normal range and there was no evidence of drift.
Conclusions : Coupled with prior bench testing and animal studies showing accuracy andhistological safety, this study confirms the Kitea ICP recording device can provide accurate data invivo over prolonged periods of time. We anticipate this will lead to first in human trials in the near
future.

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A-0003
Scope of pediatric neurosurgery as a subspeciality in a neurosurgical referral
centre of a low income country
SAGAR KOIRALA1
1

Department Of Neurosurgery, Upendra Devkota Memorial National Institute Of Neurological And Allied
Sciences, Kathmandu, Nepal

Introduction : The field of neurosurgery is expanding rapidly in Nepal with more than 80
neurosurgeons registered in the Nepalese Society of Neurosurgeons. Subspecialization indifferent field is the next step to go about. So, in this study we have looked into various pediatricneurosurgeries performed in a tertiary centre done over the past 10 years to see if pediatricneurosurgery is a viable neurosurgical subspeciality in today’s context.
Material & Methods : A retrospective study was performed at a tertiary level neurosurgical referral
centre and all pediatric cases of age less than 18 who were operated over 10 years period were
included. Data was collected from operation lists and patients discharge summaries.
Results : There were 601 pediatric neurosurgeries performed. Male to female ratio was almost 2:!.
The youngest kid operated was 2 days old. Operative cases ranged from cranial and spinal trauma,hydrocephalus, posterior fossa tumors, sellar/suprasellar tumors, lobar mass, pineal tumors, brain
abscess, vascular malformation, CVJ anomalies, spinal dysraphysm etc
Conclusions : There is enough variety as well as number of pediatric cases coming to a referral
centre for surgery. Along with development of other subspeciality in neurosurgery, pediatricneurosurgery has an equal prospect as almost 40% of the population of Nepal is under 18 years.

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A-0061
Intracranial pressure based decision making: Prediction of suspected increased
intracranial pressure with machine learning
Tadashi MIYAGAWA1, Minami SASAKI1, Akira YAMAURA1
1

Pediatric Neurosurgery, Matsudo General Medical Center, Matsudo, Japan

Introduction : Invasive intracranial pressure (ICP) monitoring is desirable for many neurosurgicalpathologies but risky for children. As non-invasive measurements of optic nerve sheath diameter(ONSD) have been revealed to accurately predict increased ICP. However, no studies have indicateda relationship among age, brain, and ventricular parameters in normal children, nor a prediction ofincreased ICP with artificial intelligence.
Material & Methods : This study enrolled 400 normal children for control and 75 children with signsof increased ICP between 2009 and 2019. Measurements of the parameters including ONSD on CT
were obtained. Supervised machine learning was applied to predict suspected increased ICP basedon CT measurements.
Results : A linear correlation was shown between ln(age) and mean ONSD (mONSD) in normalchildren, revealing mONSD = 0.36ln(age)+2.26 (R2 = 0.60). This study revealed a linear correlation of
mONSD with ln(age) and the width of the brain, not the width of the ventricles in control. The resultsof the group comparison between the control and suspected increased ICP revealed a statisticalsignificance in mONSD and the width of the ventricles. The study indicated that supervised machinelearning could be applied to predict suspected increased ICP in children, with an accuracy of 94%.
Conclusions : This study clarified three issues regarding ONSD and ICP. The mONSD was correlatedwith ln(age) and the width of the brain in normal children. The mONSD and the width of the ventricles
were statistically significant in children with signs of elevated ICP. Finally, machine learning could be
used to predict children with suspected increased ICP.

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A-0048A case of Craniometaphyseal dysplasia successfully treated by preoperative
study using a 3D printerMasamune NAGAKURA1, Tomoki NAWASHIRO1, Michihiro KURIMOTO1, Mihoko KATO1
1

Neurosurgery, Aichi Children’s Health And Medical Center, Obu, Japan

Introduction : Craniometaphyseal dysplasia (CMD) is a rare congenital osteochondrodysplasia
characterized by cranial thickening and tubular metaphyseal dysostosis Cranial expansion has
been reported to be effective in treating the increased intracranial pressure (ICP) associated withcranial thickening. However, surgical intervention has also been reported to be ineffective becauseof surgical complications and recurrence due to rethickening. In addition, the treatment strategy
depends on the age of the patient, as the disease is believed to weaken with growth.
Material & Methods : Case: 14-year-old boy. He had chronic headache, marked thickening of theskull and Chiari malformation type I. He had a characteristic facial appearance with bilateral eye
deviation, flattened nasal bridge, and a prominent forehead. Exome analysis revealed mutations in
the ANKH gene, and a diagnosis of CMD was made.
Results : Since the patient had severe and persistent headache symptoms and ICP monitoring
showed a high resting ICP of 25 mmHg, we planned cranioplasty for cranial expansion. Preoperative
studies using a 3D printer (3DP) revealed that sufficient cranial volume expansion could be achievedby removing the thickened intracranial plate and the interplanar layer. The staff members confirmed
in advance the points where massive intraoperative hemorrhage was expected. We chose to perform
a one-stage cranioplasty with endosteal plate removal. The operation was performed without trouble,
and postoperative headache symptoms were alleviated.
Conclusions : Preoperative review using 3DP enabled us to select an effective surgical technique fora rare disease with no previous treatment experience. Intraoperative precautions were also shared inadvance.

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A-0069Regression of periventricular anastomosis after indirect revascularization inpediatric patients with moyamoya disease
Elizabeth ZHENG1, Shoko HARA1, Motoki INAJI1, Yoji TANAKA1, Tadashi NARIAI1,
Taketoshi MAEHARA1
1

Neurosurgery, Tokyo Medical And Dental University, Tokyo, Japan

Introduction : The study aimed to assess the effects of indirect revascularization on pediatricpatients with moyamoya disease, focusing on the regression of periventricular anastomosis (PVA), arisk factor for hemorrhage associated with moyamoya vessels.
Material & Methods : Pediatric patients who underwent indirect revascularization between 2011 and2021 were included. Magnetic resonance angiography and arterial spin labeling images acquired
before and one year after surgery were analyzed to evaluate collateral artery formation, moyamoya
vessels, PVA regression, and cerebral blood flow (CBF) changes.
Results : Of 89 hemispheres in 58 patients (average age 8.0 ± 3.4 years, 37 females), 73.3%
showed improved collateral artery formation and increased CBF post-surgery. PVA regression was
significant (P = 0.001), especially for choroidal artery-derived PVAs (P < 0.001). Hemispheres withgood collateral formation demonstrated substantial CBF improvement (P < 0.001) and PVA regression(P = 0.015). Younger patients tended to experience PVA progression (P = 0.188), and those with the
RNF213 p.R4810K variant had a trend towards PVA regression (P = 0.069).
Conclusions : Overall, indirect revascularization in pediatric moyamoya patients led to favorable
collateral artery formation, increased CBF, and regression of PVA, particularly in those arising fromchoroidal arteries. Further research is needed to establish whether postoperative changes in PVA
translate to reduced hemorrhage risk over time.

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A-0080A Case of Cerebellar Hemorrhage in A Newborn: Cerebellar hemorrhage
association with suspected arterial dissection of the posterior inferior
cerebellar artery
Kosuke ADACHI1, Miyuki OGANE2, Minami SASAKI3, Tadashi MIYAGAWA3
1

Neurosurgery, Chiba Kaihin Munincipal Hospital, Chiba, Japan,
Neurosurgery, Chiba Medical Center, Chiba, Japan,
3
Pediatric Neurosurgery, Matsudo City General Hospital, Matsudo, Japan
2

Introduction : We herein report a 5-day-old baby boy presented with a massive cerebellar
hemorrhage due to suspected posterior inferior cerebellar artery (PICA) dissection. In the literaturesearch, there was no previous report about newborn’s arterial dissection like this case.
Material & Methods :【Case report】The patient was born by vacuum extraction at the gestationalage of 41 weeks with 3370 g birth weight. On the fifth day of life, he developed dyspnea withworsening vital signs. CT of the head showed massive cerebellar hemorrhage and then he wastransferred to our hospital. Bilateral External ventricular drainages were emergently placed for hishydrocephalus on the first day of hospitalization, then cerebellar hematoma was evacuated with
suboccipital craniotomy on day 11. Post-operative course was good, his neurological condition was
remarkably improved after ventriculoperitoneal shunt.
Results : We suspected Lt. PICA dissection was the cause of cerebellar hemorrhage. Because
under microscopic observation, the right PICA looked intact, whereas, the left PICA was swollen withdark red discoloration at the caudal loop, being a confirmative finding of arterial dissection. MRI, CT
angiography/venography, and blood tests did not show any abnormalities such as tumors, vascularanomalies, or coagulopathies. Now he is 3 years old, there are no recurrence on imaging so far, andthe left PICA is occluded.
Conclusions : We showed the world’s first case of cerebellar hematoma in a newborn, most likely
caused by ruptured PICA dissection. Although this is very rare, we suggest considering the possibilityof arterial dissection when examining neonates for cerebral hemorrhage.

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A-0175
Clinical study on hybrid operation for brain arteriovenous malformations inchildrenQingshuang ZHAO1, Junjie JING1
1

Neurosurgery, Fujian Children’s Hospital, Fuzhou, China

Introduction : To investigate the efficacy and safety of combined surgery in the treatment of brain
arteriovenous malformation (BAVM) in children.
Material & Methods : From September 2018 to August 2022, the children ( ≦18 years old) with
BAVM in the 900th Hospital of Joint Logistics Support Force and Fujian Children’s Hospital wereretrospectively analyzed. According to the admission criteria, 38 cases were included, and they weredivided into microsurgery group (25 cases) and compound surgery group (13 cases) according
to different treatment methods. The observation indexes include clinical features such as sex, age,first symptom, neurological dysfunction, GCS score, Hunt-Hess grade, imaging features such as
the location of abnormal blood vessels, Spetzler-Martin (SM) grade, intraventricular hemorrhage,
and treatment and prognosis indexes such as intraoperative bleeding, operation time, imaging cure,postoperative complications, hospitalization time, and postoperative 3m and 6m mRS scores.
Results : The proportion of female patients (P=0.042), the proportion of abnormal blood vessels insupratentorial position (P=0.034) and the proportion of SM grade above grade 3 (P=0.003) in the
combined operation group were higher than those in the microsurgery group. The intraoperative
blood loss (P<0.001), operation time (P<0.001) and postoperative hospitalization time of patients inthe microsurgery group were higher.
Conclusions : Hybrid operation is effective and safe for the treatment of BAVM in children, and BAVM
with high SM grade is more suitable for combined operation133

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A-0176
A case of a large fenestrated aneurysm of the vertebrobasilar junction in a
5-year-old boy treated with stent-assisted coil embolization.
Chihiro WATANABE1, Ai MUROI1, Mikito HAYAKAWA2, Eiichi ISHIKAWA1, Yuji MATSUMARU1
1

Neurosurgery, Medicine, University Of Tsukuba, Tsukuba, Japan,
Division Of Stroke And Cerebrovascular Disease, Medicine, University Of Tsukuba, Tsukuba, Japan

2

Introduction : Arterial aneurysms of the vertebrobasilar junction are rare and clinically challenging,particularly in pediatric patients. We report a case of a large vertebrobasilar junction aneurysm
successfully treated with coil embolization.
Material & Methods : A 5-year-old boy underwent brain magnetic resonance imaging (MRI) due tomigraine, and a 20-mm aneurysm with fenestration was found at the junction of the vertebral arteries
and the basilar artery, causing brainstem compression.
Results : He underwent endovascular coil embolization with stenting through the right vertebral
artery to the basilar artery with the occlusion of the left vertebral artery. The procedure was completedwith sufficient embolization and without complications. Two months after embolization, follow-up
MRI demonstrated refilling of the coiled aneurysm. Additional coil embolization was performed, andantiplatelet therapy was continued after the procedure. There has been no recurrence for 5 years
after the second embolization.
Conclusions : Stent-assisted coil embolization for a vertebrobasilar junction aneurysm is a safeand effective treatment option, even in pediatric patients. Continuation of antiplatelet therapy is acontroversial issue.

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A-0194
Pediatric Basilar Aneurysm: Surgical Decision-Making and Technical Nuances
for Optimal Management – A Case Report
Nadiah FUAD1, Mei Sin LIM1, Azmi Bin ALIAS1, Fadzlishah JOHANABAS1,
Thinesh Kumaran JAYARAMAN1
1

Department Of Neurosurgery, Hospital Kuala Lumpur, Kuala Lumpur, Malaysia

Introduction : Pediatric intracranial aneurysms are a rare clinical condition, with a reported
prevalence ranging from 0.5% to 4.6%. Unlike their adult counterparts, these aneurysms tend
to be larger and are more frequently located in the posterior fossa, posing unique challenges inmanagement. Here, we present a unique case of a pediatric basilar trunk aneurysm that could only
be effectively treated through microsurgery. Our objective is to report the case of a 9-year-old boy
who initially presented with generalized tonic-clonic seizures. CT brain revealed diffuse subarachnoid
hemorrhage with intraventricular bleeding, strongly suggestive of an aneurysmal bleed. Diagnostic
cerebral angiogram confirmed the presence of a basilar trunk aneurysm. Given its specific location,
microsurgery emerged as the most viable treatment option.
Material & Methods : The surgical approach involved a right pterional craniotomy, followed bydissection via the transylvian approach, transcavernous route, and transtentorium approach. To
ensure optimal exposure and gain proximal control over the aneurysm, we performed extraduralanterior clinoidectomy and intradural posterior clinoidectomy. During manipulation, an intraoperative
rupture of the aneurysm occurred, necessitating the secure placement of multiple aneurysm clips.
Subsequent reconstruction required only a single clip.
Results : Postoperatively, the child exhibited right eye ptosis and mild left upper limb monoparesis,
which gradually improved with rehabilitation.
Conclusions : Pediatric basilar artery aneurysms are exceedingly rare and pose intricate challenges
in their management. Surgical decision-making in such cases is far from straightforward, given thetechnical intricacies involved. This case underscores the importance of individualized treatment
approaches and the skillful execution of microsurgery techniques in addressing these complex
pediatric intracranial aneurysms.

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