bluuebunny/crossref_metadata_2025 huggingface dataset:
Intramedullary spinal cavernous malformation following spinal irradiation
Authors: Narayan Prithvi , Barrow Daniel L.
Published: May 2009

✓ There is a growing body of evidence in the literature suggesting that cavernous malformations of the central nervous system may develop after neuraxis irradiation. The authors discuss the case of a 17-year-old man who presented with progressive back pain and myelopathy 13 years after undergoing craniospinal irradiation for a posterior fossa medulloblastoma. Spinal magnetic resonance (MR) imaging, performed at the time of his initial presentation with a medulloblastoma, demonstrated no evidence of a malformation. Imaging studies and evaluation of cerebrospinal fluid revealed no evidence of recurrence or dissemination. Spinal MR imaging demonstrated an extensive lesion in the thoracic spine with an associated syrinx suggestive of a cavernous malformation. A thoracic laminectomy was performed and the malformation was successfully resected. Pathological examination confirmed the diagnosis. The patient did well after surgery and was ambulating without assistance 6 weeks later. To the best of the authors' knowledge, this is the second reported case in the literature and the first in the young adult age group suggesting the de novo development of cavernous malformations in the spinal cord after radiotherapy. An increased awareness of these lesions and close follow-up examination are recommended in this setting.
Posterior atlantoaxial dislocation without fracture
Authors: Yoon Do Heum , Yang Kook Hee , Kim Keung Nyun , Oh Sung Han
Published: May 2009

✓ Posterior dislocation of the atlas onto the axis without related fracture of the odontoid process is a very rare traumatic condition of which five cases have been previously reported.

The authors present a sixth case in which management was different from the others. The patient was successfully treated by open reduction of the dislocation and C1–2 transarticular screw fixation. The rarity of the lesion, the differences in diagnostic studies, and the successful treatment by safe intraoperative reduction and fixation are factors of interest in this case.
Ossification of the posterior atlantoaxial membrane
Authors: Harimaya Katsumi , Shiba Keiichiro , Nomura Hiroshi , Iwaki Toru , Takemitsu Yoshiharu
Published: May 2009

✓ The authors report a case of ossification of the posterior atlantoaxial membrane that led to the development of cervical myelopathy. Computerized tomography and magnetic resonance imaging were helpful in establishing the diagnosis, and decompressive laminectomy may be an appropriate intervention.
Alkaptonuria and lumbar disc herniation
Authors: Farzannia Akbar , Shokouhi Ghaffar , Hadidchi Shahram
Published: May 2009

✓ Alkaptonuria is a rare metabolic disease caused by deficiency of homogentisic acid oxidase and characterized by bluish-black discoloration of cartilages and skin (ochronosis). The authors report the cases of three patients with lumbar disc herniation who underwent discectomy and in whom the nucleus pulposus was discovered to be black. Alkaptonuria was diagnosed after discectomy. Discal herniation requiring surgery is unusual in alkaptonuria, with only a few reports. The symptoms in the three patients disappeared after surgery and no symptoms were demonstrated on follow-up examination.
Low-pressure headaches and spinal cord herniation
Authors: Inoue Tomohiro , Cohen-Gadol Aaron A. , Krauss William E.
Published: May 2009

✓ Almost 40 cases of spontaneous transdural spinal cord herniation have been reported in the literature. These patients often present with gait disturbance and sensory changes, and their condition is diagnosed as Brown—Séquard syndrome. The pathogenesis of this condition has remained poorly understood. In particular, there is no agreement whether the dural defect is acquired or congenital. In the reported case, a 21-year-old man presented with a 3-year history of intermittent low-pressure headaches consistent with intracranial hypotension. Eventually, the headaches resolved but he developed myelopathy due to a spinal cord herniation. In this case, the authors hypothesize that the progressive spinal cord herniation through a spontaneous dural tear sealed the site of the cerebrospinal fluid leak, causing the resolution of headaches.
Intraoperative cervical epidurography: a simple modality for assessing the adequacy of decompression during anterior cervical procedures
Authors: Hejazi Nedal , Witzmann Alfred , Hassler Werner
Published: May 2009

Object. Intraoperative cervical epidurography (ICE) was used during anterior cervical procedures to assess the success of bone resection and indicate the need for immediate correction in the event of inadequate decompression.

Methods. The adequacy of decompression was assessed by the operating neurosurgeon who performed ICE after anterior microdiscectomy with exposure of the dura mater. If the decompression was deemed inadequate, additional bone was removed using a high-speed drill. Epidurography was conducted after each subsequent decompression until adequate bone removal was achieved. This was undertaken in 39 patients undergoing anterior cervical procedures. Nine patients underwent corpectomy, 21 one-level, and nine two-level discectomy. The ICE revealed insufficient resections requiring additional bone removal in 14 (36%) of the 39 patients.

Conclusions. The goal of ICE is to ensure adequate decompression, and if such has not been achieved, to allow for additional immediate bone excision. Furthermore, ICE provides additional real-time control of the position of cages and screws to avoid dural tear or spinal cord compression. Because of this immediate feedback, the success rate of anterior cervical procedures can be improved. The advantages of this modality include real-time assessment, low cost, simplicity, and speed.
Guide device for percutaneous placement of translaminar facet screws after anterior lumbar interbody fusion
Authors: Jang Jee Soo , Lee Sang Ho , Lim Sang Rak
Published: May 2009

Because the degree of immediate stabilization provided by cage-assisted anterior lumbar interbody fusion (ALIF) has been shown by several studies to be inadequate, supplementary posterior fixation, such as that created by translaminar or transpedicle screw fixation, is necessary. In this study, the authors studied the ALIF-augmentation procedure in which a special guide device is used to place percutaneously translaminar facet screws in 18 patients with degenerative lumbar disease. The minimum follow-up period was 1 month (mean 6 months, range 1–13 months). Degenerative spondylolisthesis with foraminal stenosis was diagnosed in nine patients, associated degenerative disc disease alone or combined with foraminal stenosis in eight, and recurrent disc herniation in one. Following screw placement, computerized tomography scanning was conducted to evaluate the accuracy of the facet screw positioning.

All screws were properly placed. No screw penetrated the spinal canal or injured the neural structures. Excellent or good clinical outcomes were demonstrated in all patients at the last follow up.

The use of this guide device for post—ALIF percutaneous translaminar facet screw fixation represents a safe, accurate, and minimally invasive modality with which to achieve immediate solid fixation in the lumbar spine.
Evaluation of pedicle screw position on computerized tomography scans
Authors: Yeom Jin Sup , Chung Moon Sang , Lee Choon-Ki , Kim Yeongho , Kim Namkug , Lee Jae Bum
Published: May 2009

✓ The quality of a computerized tomography (CT) scan is significantly reduced by metal artifact caused by a pedicle screw system. The purpose of this study was to develop a method of facilitating the evaluation of pedicle screw position on CT scans obtained after screw insertion.

The authors developed an algorithm to process spiral CT scans in a personal computer. This uses a digital image enhancement technique, the curve change-based intensity transformation algorithm. This method can generate a clear image of the screw outlines while reducing metal artifact. The resulting images are displayed in arbitrary planes as well as in axial, coronal, and sagittal planes, to support better the evaluation of pedicle screw position.

The algorithm was tested using CT scans obtained in 37 patients in whom 186 pedicle screws had been placed. There were five types of screw systems, all of which were made of titanium alloys. In all cases algorithm-based determination of screw position became more convenient and more accurate than when using the conventional bone window setting. In addition, it provided better soft-tissue visualization than the bone window.

The software, by displaying clear outlines of screws and decreasing metal artifact, as well as by reconstructing the images in arbitrary planes, was more helpful in identifying the position of pedicle screws than the conventional bone window setting.
Cervicothoracic radiculopathy treated using posterior cervical foraminotomy/discectomy
Authors: Harrop James S. , Silva Marco T. , Sharan Ashwini D. , Dante Steven J. , Simeone Frederick A.
Published: May 2009

Object. The authors conducted a study to identify the effectiveness and morbidity rate associated with treating cervicothoracic disc disease (radiculopathy) via a posterior approach.

Methods. Nineteen patients underwent posterior cervicothoracic laminoforaminotomy during a 5.6-year period. Medical records, imaging studies, office charts, hospital records, and phone interview data were reviewed. Specific information analyzed included patient demographics, side of lesion, and conservative treatment, symptoms, and pre- and postoperative pain levels. Pain was rated using a visual analog scale and classified into a radicular and neck component.

Data in 19 patients (seven women and 12 men) who underwent 20 procedures (one patient underwent separate bilateral foraminotomies) were analyzed. The mean patient age was 54.8 years (range 38–73 years), and the follow-up period ranged from 23 to 62 months. Symptom duration ranged from 1 to 14 months (mean 3.4 months) and consisted of weakness, numbness, and painful radiculopathies in 11, 16, and 20 cases, respectively. Motor weakness was identified in 11 of 19 patients (mean grade of 4.35), and postoperatively strength normalized in eight of 11 (mean grade of 4.79). The improvement in motor scores was significant (p = 0.007). Pain was the most common presenting symptom. Preoperative radiculopathies were rated between 0 and 10 (mean 7.45), and postoperatively scores were reduced to 0 to 3 (mean 0.2) which was significant (p < 0.0001). Preoperative neck pain was rated between 0 and 8 (mean 2.55), and on follow up ranged from 0 to 2 (mean 0.5), which was also significant (p = 0.001).

Conclusions. Posterior cervicothoracic foraminotomy was a safe and effective procedure in the treatment of patients with laterally located disc herniations.
Endoscopic anterior cervical foraminotomy for unilateral radiculopathy: anatomical morphometric analysis and preliminary clinical experience
Authors: Saringer Walter F. , Reddy Brian , Nöbauer-Huhmann Iris , Regatschnig Rene , Reddy Marion , Tschabitscher Manfred , Knosp Engelbert
Published: May 2009

Object. Cervical radiculopathy is typically caused by posterolateral disc herniation or spondylotic foraminal stenosis, either of which may compress the ventral aspect of the nerve root. The authors undertook a study to establish the feasibility of performing an endoscopic approach for anterior cervical foraminotomy (ACFor) in a clinical setting.

Methods. Application of this method on cadavers was conducted to verify the practicability of this technique. The clinical study included 16 patients (eight men and eight women; mean age 46.6 years) all presenting with unilateral radicular symptoms (one at two adjacent ipsilateral levels), which were associated with various degrees of neck pain. Disc herniations and/or uncovertebral osteophytes were confirmed on magnetic resonance imaging and high-resolution computerized tomography scanning. A total of 17 endoscopic ACFors (one two-level procedure) were performed using a rigid glass endoscope (25° angled, 3-mm diameter, 10-mm length) mounted on a tubular retractor.

No major surgery-related complications were encountered. During a mean follow-up period of 13.8 months an average absolute improvement of 44% (p > 0.05) in the neck disability index score and of 96% (p > 0.05) in the visual analog scale score for radicular pain (compared with the preoperative score) was observed. During the follow-up period strength improved to normal in 84% and sensory deficit in 80% of the patients. The overall subjective patient satisfaction rate was 87.6%; the return-to-work rate after 4 weeks was 81.4%.

Conclusions. The advantages of endoscopic ACFor include minimial surgical exposure, improved intraoperative visualization, direct decompression of the nerve root, and the preservation of the intervertebral disc and the motion segment.
Suitability of bioresorbable cages for anterior cervical fusion
Authors: Cahill David W. , Martin George J. , Hajjar Michael V. , Sonstein William , Graham Lloyd B. , Engelman Robert W.
Published: May 2009

Object. The authors conducted a pilot study to determine whether a bioresorbable intervertebral fusion device composed of 85/15 polylactide—polyglycolide (PLA-PGA) copolymer packed with bone autograft is a suitable alternative to promote arthrodesis after anterior cervical discectomy (ACD) in a caprine model.

Methods. The caprine cervical spine model has been used to evaluate interbody healing and fusion after application of bone grafts and instrumentation. Whether a bioresorbable device is suitable for facilitating intervertebral bone union has not been determined. Twelve goats underwent two-level ACD and fusion; eight received bioresorbable cages packed with autologous bone, and four received autologous bone alone. Goats were maintained without an orthosis and after 12 weeks underwent physical, radiographic, and histological evaluation.

Cages had structurally degraded, and two had become extruded. Stable intervertebral union developed in three (19%) of 16 cage-implanted interspaces, and one (14%) of seven bone autograft—implanted interspaces; each was judged manually to be rigid (Grade 2), radiographically to be bridged by new osseous densities (Grade 2), and histologically to have marked new bone formation (Grade 3). A primarily fibrous union, however, stabilized the cage-implanted interspaces, and eight (50%) had developed a 4 to 6—mm foreign body granuloma. These interposed soft tissues were not present in the stable autologous bone—implanted interspace, which had successfully become fused.

Conclusions. Interbody cages composed of 85/15 PLA-PGA copolymer contributed to a stable fibrous union, degraded, and produced granuloma after 12 weeks. Additional evaluations are necessary to determine whether other copolymer mixtures, or other bioresorbable materials, can contribute to an arthodesis without deleterious consequences.
Craniovertebral junction fixation with transarticular screws: biomechanical analysis of a novel technique
Authors: Gonzalez L. Fernando , Crawford Neil R. , Chamberlain Robert H. , Perez Garza Luis E. , Preul Mark C. , Sonntag Volker K. H. , Dickman Curtis A.
Published: May 2009

Object. The authors compared the biomechanical stability resulting from the use of a new technique for occipitoatlantal motion segment fixation with an established method and assessed the additional stability provided by combining the two techniques.

Methods. Specimens were loaded using nonconstraining pure moments while recording the three-dimensional angular movement at occiput (Oc)—C1 and C1–2. Specimens were tested intact and after destabilization and fixation as follows: 1) Oc—C1 transarticular screws plus C1–2 transarticular screws; 2) occipitocervical transarticular (OCTA) plate in which C1–2 transarticular screws attach to a loop from Oc to C-2; and (3) OCTA plate plus Oc—C1 transarticular screws.

Occipitoatlantal transarticular screws reduced motion to well within the normal range. The OCTA loop and transarticular screws allowed a very small neutral zone, elastic zone, and range of motion during lateral bending and axial rotation. The transarticular screws, however, were less effective than the OCTA loop in resisting flexion and extension.

Conclusions. Biomechanically, Oc—C1 transarticular screws performed well enough to be considered as an alternative for Oc—C1 fixation, especially when instability at C1–2 is minimal. Techniques for augmenting these screws posteriorly by using a wired bone graft buttress, as is currently undertaken with C1–2 transarticular screws, may be needed for optimal performance.
In vitro high-field magnetic resonance imaging—documented anatomy of a fetal myelomeningocele at 20 weeks' gestation. A contribution to the rationale of intrauterine surgical repair of spina bifida
Authors: Beuls Emile A. M. , Vanormelingen Linda , van Aalst Jasper , Vandersteen Marjan , Adriaensens Peter , Cornips Erwin M. J. , Vles Hans J. S. , Gelan Jan
Published: May 2009

Object. It remains uncertain if closure of a myelomeningocele at midgestation changes the neurological condition at birth in an infant born with spina bifida. The authors conducted a study to provide a detailed analysis of the morphology of the spinal cord with the myelomeningocele at the time fetal surgery usually is performed.

Methods. The myelomeningocele of a 20-week-gestation-age fetus was examined, and data were compared with those obtained in a neurologically intact specimen of the same age. In vitro high-field 9.4-tesla magnetic resonance (MR) microscopy was used to examine the fetal material.

High-field MR spectroscopy provided images in the three orthogonal planes with a resolution comparable with low-power optical microscopy. The authors observed that the fetal cord of the myelomeningocele specimen was tapered and tethered at S3–4 while the conus medullaris in the normal fetus reaches L-4.

No neurulation defects were noted. The axial MR images clearly revealed the nonfusion of the mesodermal structures.

The absence of neurulation defects suggests that at least in some cases of spina bifida the spinal cord initially is well developed but is damaged later on chemically and mechanically. This might be an argument in favor of intrauterine myelomeningocele repair. By 20 weeks' gestation, however, the deformation of the cord inside the myelomeningocele is severe. An optimization of the preoperative assessment by means of MR imaging therefore might be considered a valuable contribution to intrauterine surgery. The in vitro high-field MR microscopic findings of this study could be used as references for clinical intrauterine MR imaging.

Conclusions. The detailed in vitro high-field MR analysis of a 20-week-gestation-age fetus with spina bifida demonstrated that an improvement of the preoperative intrauterine imaging should be pursued to detect those cases without neurulation defects and with minimal deformation of the spinal cord.
The Wilhelm Tell technique for anterior lumbar interbody fusion
Authors: Markwalder Thomas-Marc , Wenger Markus , Elsig Jean-Pierre , Laloux Etienne
Published: May 2009

✓ Experience indicates that stand-alone cages may lack the necessary stability to secure highly unstable motion segments at the lumbosacral junction.

The authors have designed a special carbon fiber composite interbody cage that allows additional screw placement in anterior lumbar interbody fusion procedures performed at the lumbosacral junction.
Cervical laminoplasty: a critical review
Authors: Ratliff John K. , Cooper Paul R.
Published: May 2009

Object. The technique of cervical laminoplasty was developed to decompress the spinal canal in patients with multilevel anterior compression caused by ossification of the posterior longitudinal ligament or cervical spondylosis. There is a paucity of data confirming its superiority to laminectomy with regard to neurological outcome, preserving spinal stability, preventing postlaminectomy kyphosis, and the development of the “postlaminectomy membrane.”

Methods. The authors conducted a metaanalysis of the English-language laminoplasty literature, assessing neurological outcome, change in range of motion (ROM), development of spinal deformity, and complications. Seventy-one series were reviewed, comprising more than 2000 patients.

All studies were retrospective, uncontrolled, nonrandomized case series. Forty-one series provided postoperative recovery rate data in which the Japanese Orthopaedic Association Scale was used for assessing myelopathy. The mean recovery rate was 55% (range 20–80%). The authors of 23 papers provided data on the percentage of patients improving (mean ∼80%). There was no difference in neurological outcome based on the different laminoplasty techniques or when laminoplasty was compared with laminectomy. There was postlaminoplasty worsening of cervical alignment in approximately 35% and with development of postoperative kyphosis in approximately 10% of patients who underwent long-term follow-up review. Cervical ROM decreased substantially after laminoplasty (mean decrease 50%, range 17–80%). The authors of studies with long-term follow up found that there was progressive loss of cervical ROM, and final ROM similar to that seen in patients who had undergone laminectomy and fusion. In their review of the laminectomy literature the authors could not confirm the occurrence of postlaminectomy membrane causing clinically significant deterioration of neurological function. Postoperative complications differed substantially among series. In only seven articles did the writers quantify the rates of postoperative axial neck pain, noting an incidence between 6 and 60%. In approximately 8% of patients, C-5 nerve root dysfunction developed based on the 12 articles in which this complication was reported.

Conclusions. The literature has yet to support the purported benefits of laminoplasty. Neurological outcome and change in spinal alignment are similar after laminectomy and laminoplasty. Patients treated with laminoplasty develop progressive limitation of cervical ROM similar to that seen after laminectomy and fusion.
Ultrasonographic screening in infants with isolated spinal strawberry nevi
Authors: Allen Rebecca M. , Sandquist Michael A. , Piatt Joseph H. , Selden Nathan R. W.
Published: May 2009

Object. The authors performed spinal ultrasonography and/or magnetic resonance (MR) imaging in 20 consecutive newborns with spinal strawberry nevi.

Methods. In 15 patients the strawberry nevi were isolated and in five they were associated with other cutaneous markers of occult spinal dysraphism (OSD). In four of five patients with additional cutaneous markers, but in none of those without, MR imaging and surgical exploration demonstrated OSD. The authors found that strawberry nevi in isolation do not appear to indicate underlying dysraphic states. The sparse clinical literature on this topic, which is reviewed, confirms an association between OSD and strawberry nevi presenting in conjunction with other cutaneous signatures. By contrast, spinal strawberry nevi occurring alone may not indicate the presence of underlying dysraphism.

Conclusions. A prospective study of larger numbers of patients with isolated strawberry nevi, undergoing MR imaging evaluation, is necessary to determine whether neuroimaging screening in these patients is indicated.
Spinal meningiomas in patients younger than 50 years of age: a 21-year experience
Authors: Cohen-Gadol Aaron A. , Zikel Ofer M. , Koch Cody A. , Scheithauer Bernd W. , Krauss William E.
Published: May 2009

Object. Spinal meningiomas occur most frequently in older patients. They are well-circumscribed and slow-growing tumors that are associated with good patient outcomes following surgery. Spinal meningiomas occurring in younger patients may be more aggressive, with a worse prognosis. The authors present their 21-year experience with spinal meningiomas in patients younger than 50 years of age.

Methods. The authors reviewed data obtained in 40 patients (age < 50 years) treated at the Mayo Clinic, Rochester, during the past 21 years; in all cases the lesions were histologically confirmed spinal meningiomas. Five men (12.5%) and 35 women (87.5%) (mean age 34.5 ± 10.9 years) underwent 52 operations for 41 tumors. The mean follow-up duration was 82 ± 93 months (range 0–445 months). The data obtained in these patients were compared with those derived from a random control cohort of 40 patients older than age 50 years in whom spinal meningiomas were resected at the Mayo Clinic during a similar period. In this cohort, there were 33 women and seven men whose mean age was 67.1 ± 9.5 years. The mean follow-up duration for the older group was 88 ± 72.3 months (range 18–309 months).

Compared with the random cohort of older patients, younger patients there tended to have more tumors located in the cervical spine (39%) as well as a greater number of predisposing factors such as neurofibromatosis Type 2, radiation exposure, or trauma. Nine (22%) of the patients younger than 50 years of age required reoperation for residual or recurrent tumor compared with two (5%) in the older patient control group. The overall mortality rate at the completion of the study for the younger patients was 10%.

Conclusions. Spinal meningiomas in younger patients have a worse prognosis than similar tumors in older patients.
Microsurgical midline approach for the decompression of extraforaminal L5—S1 stenosis
Authors: Park Youn-Kwan , Kim Joo Han , Chung Hung Seob , Suh Jung Keun
Published: May 2009

Object. When performing surgery, the extraforaminal window is very narrow at the L5—S1 level. The authors describe a microsurgical method for decompression of the L-5 nerve root trapped between a marginal osteophyte of the vertebral body and the transverse process. The procedure was performed in 16 patients with extraforaminal stenosis.

Methods. The cranial part of the L5—S1 facet joint and the caudal portion of the pedicle and transverse process of L-5 were removed via a midline skin incision and partial resection of the pars interarticularis; a high-speed drill was used as was a surgical microscope. The affected nerve root was decompressed and mobilized cranially.

Postoperatively all patients reported excellent relief of their sciatic pain, and there were no technique-associated complications. There was no recurrence during the follow-up period, that ranged from 14 to 70 months.

Conclusions. The authors recommend this technique for the effective decompression of symptomatic extraforaminal L5—S1 stenosis. The need for a dangerous and tedious removal of the vertebral osteophyte together with spinal fusion is avoided.
Neuroprotective effects of GYKI 52466 on experimental spinal cord injury in rats
Authors: Çolak Ahmet , Soy Osman , Uzun Hafize , Aslan Özcan , Barut Seref , Belce Ahmet , Akyildiz Ayşenur , Taşyürekli Mustafa
Published: May 2009

Object. The toxic effects of glutamate in the central nervous system are well known. This neurotoxicity occurs through metabotropic and ionotropic receptors, the latter group composed of N-methyl-d-aspartate, α-amino-3-hydroxy-5-methylisoxazole-4-proprionic acid (AMPA), and kainate receptors. The authors investigated the neuroprotective effects of GYKI 52466, a 2,3-benzodiazepine that is a selective and potent AMPA receptor antagonist, in a rat spinal cord trauma model.

Methods. Sixty Wistar albino rats were studied in three groups of 20 animals each: sham-operated controls (Group 1); spinal cord—injured rats (Group 2); and spinal cord—injured plus GYKI 52466—treated rats (Group 3). In Groups 2 and 3, spinal cord injury (SCI) was induced at the thoracic level by applying an aneurysm clip to the cord for 1 minute. One minute after the clip was removed, the rats in Group 3 received an intraperitoneal injection of 15 mg/kg GYKI 52466. Responses to injury and treatment were evaluated based on biochemical parameters (lipid peroxidation and adenosine 5′-triphosphate [ATP] levels in tissue), and on light and transmission electron microscopy findings in cord tissue collected at different times post-SCI. Five rats from each group underwent assessment of functional recovery at 1, 3, and 5 days after SCI; evaluation was performed using the inclined-plane technique and Tarlov motor grading scale.

The mean lipid peroxidation levels in Groups 1 and 2 were 21.73 ± 4.35 and 35.53 ± 2.99 nmol/g of wet tissue, respectively. The level in Group 3 was 27.98 ± 3.93 nmol/g of wet tissue, which was significantly lower than that in Group 2 (p < 0.01). The mean ATP levels in Groups 1 and 2 were 166.21 ± 25.57 and 41.72 ± 12.28 nmol/g of wet tissue, respectively. The ATP level in Group 3 was 85.82 ± 13.92 nmol/g of wet tissue, which was significantly higher than that in Group 2 (p < 0.01). Light microscopic examination of Group 2 tissues showed hemorrhage, necrosis, polymorphonuclear leukocyte infiltration, and vascular thrombi. In contrast, the examination of Group 3 tissues showed limited hemorrhage and no necrosis or vascular thrombi. The most prominent findings in Group 2 were hemorrhage and necrosis, whereas the most prominent findings in Group 3 were focal hemorrhage and leukocyte infiltration. Electron microscopy demonstrated that GYKI 52466 protected the neurons, myelin, axons, and intracellular organelles. The mean inclined-plane angles in Groups 1, 2, and 3 were 65°, 40 to 45°, and 55°, respectively. Motor scale results in all groups showed a similar trend.

Conclusions. The findings in this rat model suggest that GYKI 52466 may provide significant therapeutic protection from secondary damage after acute SCI. This agent may be a viable alternative treatment for SCI.
Spontaneous intracranial hypotension from intradural thoracic disc herniation
Authors: Rapport Richard L. , Hillier David , Scearce Tim , Ferguson Camari
Published: May 2009

✓ Spontaneous intracranial hypotension (SIH) may result from occult leaks anywhere along the neuraxis. Although this syndrome has been recognized over the past 10 years in the neurology and radiology literature, the typical magnetic resonance (MR) imaging picture and clinical course are less well known to neurosurgeons. The authors describe the case of a patient with positional headache and MR imaging findings typical of SIH that resulted from an intradural disc herniation.
Multiplication of infantile spinal lipomas after surgical untethering
Authors: Morimoto Kazuyoshi , Takemoto Osamu , Wakayama Akatsuki
Published: May 2009

✓ The authors reviewed 63 cases of patients with spinal lipomas who had undergone surgical untethering in childhood and found two infants in whom multiplication of the lipomas occurred within 1 year postoperatively. More importantly, the lipomas dramatically increased in size during infancy. In each case, the pathological findings on reoperation were identical to those in the first surgery. Subsequent imaging revealed no change in size of the lesions by 10 and 7 years after reoperation, respectively. This potential for growth of the lipomas should be kept in mind in infants with spinal lipomas who should undergo follow-up neuroimaging.
Bifocal myxopapillary ependymoma of the terminal filum: the end of a spectrum?
Authors: Hallacq Paul , Labrousse François , Streichenberger Nathalie , Lisii Dan , Fischer Georges
Published: May 2009

✓ Myxopapillary ependymomas represent the most frequent type of ependymomas found at the conus medullaris—cauda equina-terminal filum level. They are neuroectodermal tumors mainly observed during the fourth decade of life. Pediatric cases have been rarely described at an age range of 10 to 13 years. Myxopapillary ependymomas are typically solitary tumors involving the terminal filum. Simultaneous discovery of two tumors located both on the terminal filum has been reported once. The pathogenesis of this focal ependymoma located at the same embryological level, on the terminal filum, is uncertain; it may represent one end of a spectrum, the other end being the giant ependymoma of the terminal filum.
Spinal cord edema: unusual magnetic resonance imaging findings in cervical spondylosis
Authors: Lee Jangbo , Koyanagi Izumi , Hida Kazutoshi , Seki Toshitaka , Iwasaki Yoshinobu , Mitsumori Kenji
Published: May 2009

Object

Spinal cord edema is a rare radiological finding in chronic degenerative disorders of the spine. Between 1997 and 2001, the authors treated six patients with cervical spondylotic myelopathy in whom postoperative spinal cord edema was demonstrated. The authors describe the radiological and clinical features of this unusual condition.

Methods

The six patients were all men, and ranged in age from 44 to 72 years. All patients presented with mild quadriparesis and underwent laminoplasty or anterior fusion. Preoperative magnetic resonance (MR) imaging revealed marked spinal cord compression with intramedullary hyperintensity on T2-weighted sequences and spinal cord enhancement at the compression level after administration of Gd.

After surgery, spinal cord edema was observed in all patients; the spinal cord appeared swollen on the postoperative MR images. Preoperative and postoperative Gd-enhanced MR imaging demonstrated clear enhancement of the white matter at the compressed segment. Neurologically, five of six patients experienced good improvement of symptoms; however, the spinal cord edema as documented on follow-up MR imaging persisted for several months after surgery.

Conclusions

The radiological characterization of spinal cord edema was based on the reversible white matter lesion most likely caused by disturbed local venous circulation induced by chronic spinal cord compression. Such unusual MR findings in cervical spondylotic myelopathy should be differentiated from intramedullary spinal cord tumors, demyelinating disorders, or inflammatory processes.
Synovial cysts of the lumbar spine: surgery-related results and outcome
Authors: Pirotte Benoit , Gabrovsky Nicolay , Massager Nicolas , Levivier Marc , David Philippe , Brotchi Jacques
Published: May 2009

Object

The authors conducted a study to determine the surgery-related results and outcomes in patients with synovial cysts of the lumbar spine. They emphasize several specific characteristics useful in clinical management.

Methods

Forty-six consecutive patients with 54 lumbar synovial cysts underwent surgery between 1990 and 2001. A retrospective analysis of the clinical presentation and follow-up data, radiological findings, and surgical techniques was performed. Clinical presentation was dominated by acute or subacute sciatic pain. No specific symptom allowed differentiation of synovial cyst from a lumbar disc herniation. Computerized tomography scanning aided in establishing the correct diagnosis in 19 of 30 cases and magnetic resonance (MR) imaging did so in all cases. Three of the 46 patients presented with bilateral lumbar synovial cysts. The L4–5 level was affected in 61%, and radiological signs of disc degeneration/spondylosis were observed in 54% of the patients. Immediate symptom relief without local recurrence was obtained by complete microsurgical excision in which bipolar coagulation was used to remove the synovial membrane and in which the interapophysial joint was preserved. During the 1st postoperative year, a newly formed symptomatic synovial cyst developed on the contralateral side or at a superior vertebral level in five patients. They underwent surgery; results were good and there was no recurrence.

Conclusions

The findings in this series suggest that synovial cysts can occur at multiple lumbar sites within a short period of time and could be predisposed to developing in certain individuals, predominantly in women older than 40 years of age. Postoperative follow up is recommended and MR imaging mandatory in cases of recurrent sciatica.
Focal fractionated radiotherapy for intramedullary spinal arteriovenous malformations: 10-year experience
Authors: Hida Kazutoshi , Shirato Hiroki , Isu Toyohiko , Seki Toshitaka , Onimaru Rikiya , Aoyama Hidefumi , Ushikoshi Satoshi , Miyasaka Kazuo , Iwasaki Yoshinobu
Published: May 2009

Object

Radiosurgical treatment of spinal arteriovenous malformations (AVMs) is becoming a practical therapeutic option as methodology improves, but no comparative study has yet been published on focal fractionated radiotherapy. The authors report their experience with conventional and hypofractionated radiotherapy for spinal AVM.

Methods

Candidates for this study were patients who experienced symptoms due to an intramedullary AVM but were ineligible for embolization or surgery. Of 21 patients with spinal AVMs, 10 cases in a 10-year period met this criterion. Angiography and contrast-enhanced computerized tomography scanning were used for treatment planning in all cases. Fractionated radiotherapy was performed using a linear accelerator, extracranial immobilization system, and frequent orthogonal linacographic verification. The starting radiation dose was 32 Gy in two, 36 Gy in three, and 40 Gy in two patients, in a regimen involving 1.8 to 2—Gy daily fractions; this was recently changed to a hypofractionation schedule of 30 Gy (in eight sessions) in one and 20 Gy (in four sessions) in two patients.

Results

The follow-up period ranged from 26 to 124 months (median of 49 months). There were no hemorrhages nor any adverse reactions attributable to irradiation. Of the seven patients who consented to undergo follow-up angiography, the nidus size decreased in five, but complete obliteration did not occur in any patient.

Conclusions

Because no patient experienced adverse effects, the maximum tolerable radiation dose for the spinal cord associated with an AVM could not be identified, although it presumably is higher than those administered. The lack of rebleeding in patients in whom complete angiographic occlusion was absent suggests that the natural history of spinal AVMs may be less aggressive than previously reported.
Computerized tomography—guided percutaneous transforaminodiscal biopsy sampling of vertebral body lesions
Authors: Sucu Hasan Kamil , Bezircioglu Hamdi , Çiçek Canan , Ersşahin Yusuf
Published: May 2009

Object

The posterolateral approach is the common route for obtaining percutaneous biopsy samples in lumbar and thoracic vertebral bodies (VBs). This procedure, however, is associated with the risk of complications. Because of this, the authors devised a new method for percutaneous biopsy sampling of VB lesions.

Methods

The percutaneous computerized tomography (CT)—guided transforaminodiscal biopsy procedure was undertaken in 20 patients during a 10-month period. The VBs in 18 cases were successfully accessed using this technique. There were no procedure-related complications.

Conclusions

Transforaminodiscal CT-guided spinal biopsy procedure is a safe and effective method for accessing VB lesions. It is possible to obtain a biopsy sample in the major part of the VB. This technique is a good alternative to the standard posterolateral approach.
Image-guided resection for thoracic ossification of the ligamentum flavum
Authors: Seichi Atsushi , Nakajima Susumu , Takeshita Katsushi , Kitagawa Tomoaki , Akune Toru , Kawaguchi Hiroshi , Nakamura Kozo
Published: May 2009

Object

The purpose of this study was to evaluate the advantages of using an image guidance system to aid in the resection of ossified of the ligamentum flavum (OLF) in the thoracic spine. The procedure and surgery-related outcome are discussed.

Methods

Ten patients with myelopathy underwent laminotomy with medial facetectomy and an image guidance system was used to remove the OLF. No neurological deterioration occurred, and postoperative computerized tomography scanning demonstrated successful decompression and good preservation of the lateral parts of the facet joints.

Conclusions

The image guidance system allows accurate resection of the OLF while preserving as much as possible the facet joints and posterior elements of the thoracic spine.
Surgical management of lumbosacral nerve root hemangioblastomas in von Hippel—Lindau syndrome
Authors: Lonser Russell R. , Wait Scott D. , Butman John A. , Vortmeyer Alexander O. , Walther McClellan M. , Governale Lance S. , Oldfield Edward H.
Published: May 2009

Object

Hemangioblastomas in the lumbosacral region are rare, and the authors of prior reports have not defined the surgical management, histopathological features, or outcome in a group of patients after resection of these tumors. To identify features that will help guide the operative and clinical management of these lesions, the authors reviewed data obtained in a series of patients with von Hippel—Lindau syndrome who underwent resection of lumbosacral nerve root hemangioblastomas.

Methods

Six consecutive patients (three men and three women; mean age at surgery 39 years [range 31–48 years]) who underwent operations for resection of lumbosacral nerve root hemangioblastomas were included in this study. The mean follow-up period was 23 months (range 6–45 months). Data derived from examination, hospital charts, operative findings, histopathological analysis, and magnetic resonance imaging were used to analyze surgical management and clinical outcome. The resected tumors were located in the lumbar (five cases) or sacral (one case) regions; the mean tumor size was 2728 mm3 (range 80–15,022 mm3). Consistent with central nervous system (CNS) regional variation of space available to accommodate the neural compressive effect of the hemangioblastoma size, the mean tumor volume (2728 mm3) of these symptomatic lesions was much larger than that of symptomatic hemangioblastomas resected in the other regions of the CNS. Histopathological examination showed infiltration of the associated nerve root by the hemangioblastoma in each case. In five of the six patients complete resection was achieved, and in one patient intradural exploration of two hemangioblastomas was performed, but resection was not achieved because of motor root involvement. In all cases involving complete resections the patients experienced symptomatic improvement.

Conclusions

Lumbosacral nerve root hemangioblastomas can be safely removed in most patients with von Hippel—Lindau syndrome. Generally, hemangioblastomas of the lumbosacral nerve roots should be resected when they become symptomatic. Because these neoplasms appear to originate from the nerve root, it is necessary to sacrifice the nerve root from which the hemangioblastoma originates to achieve complete resection.
Topical mitomycin C—induced inhibition of postlaminectomy peridural fibrosis in rabbits
Authors: Dogulu Fikret , Kurt Gokhan , Emmez Hakan , Erdem Ozlem , Memis Leyla , Baykaner Kemali , Ceviker Necdet
Published: May 2009

Object

The authors conducted a study to determine the effectiveness of mitomycin C in preventing postlaminectomy peridural fibrosis in rabbits.

Methods

Laminectomies were performed at L-4 in 12 rabbits. Color-coded cotton pads soaked either with 0.02% mitomycin C or saline were applied in a blinded fashion to the operative sites, with saline-treated laminectomy sites serving as controls. The rabbits were killed 30 days after surgery. The extent of peridural fibrosis was evaluated by histological analysis.

The mitomycin C—treated sites showed significantly decreased peridural fibrosis.

Conclusions

Peridural fibrosis can be a devastating condition that develops after laminectomy. Topical application of mitomycin C may be a successful method of preventing postlaminectomy peridural fibrosis.
Biomechanical comparison of expandable cages for vertebral body replacement in the cervical spine
Authors: Kandziora Frank , Pflugmacher Robert , Schaefer Jan , Scholz Matti , Ludwig Kathrin , Schleicher Philip , Haas Norbert P.
Published: May 2009

Object

Recently, expandable cages for vertebral body replacement in the cervical spine have been developed. The purpose of this study was to compare the biomechanical properties of expandable cages with those of a tricortical iliac crest graft and a nonexpandable cage.

Methods

Forty human cervical spines (C3–5) were tested in flexion, extension, axial rotation, and lateral bending. First all motion segments were evaluated intact. After corpectomy of C-4 the spines were divided into five groups of eight and the following stabilization techniques were used: 1) autologous iliac crest bone graft; 2) mesh titanium cage; 3) anterior distraction device; 4) Synex-C titanium; and 5) Synex-C PEEK. Additionally, anterior plating and anterior plating plus posterior screw/rod fixation were applied. Stiffness, range of motion, and neutral and elastic zones were determined.

In comparison with the intact motion segment all implants significantly increased stiffness in flexion and bending, but decreased stiffness in extension. There were no biomechanical differences between the nonexpandable and expandable cages. Furthermore, there were no biomechanical differences between the tricortical iliac crest graft and the cages, except for Synex-C in rotation. Additional anterior plating significantly increased biomechanical stiffness in all test modes; particularly in rotation mode, combined anterior-posterior stabilization increased stiffness by up to 102% compared with anterior plating alone.

Conclusions

In comparison to a tricortical iliac crest bone graft and a nonexpandable cage, expandable cages have no biomechanical advantages. Due to the low extension and rotational stiffness, none of the implants can be recommended as a stand-alone device. Additional anterior plating increased biomechanical stability adequately. Therefore, additional posterior stabilization should only be considered in cases of severe rotational instability of the cervical spine.
Biomechanical analysis of multilevel cervical corpectomy and plate constructs
Authors: Porter Randall W. , Crawford Neil R. , Chamberlain Robert H. , Park Sung Chan , Detwiler Paul W. , Apostolides Paul J. , Sonntag Volker K. H.
Published: May 2009

Object

The authors compared the biomechanical stability of two multilevel cervical constructs involving the placement of equal size anterior cervical plates (ACPs) after decompressive surgery: the first is placed after three-level corpectomy with strut graft and the second after two-level corpectomy and aggressive discectomy with strut graft. In addition, both constructs were evaluated with and without the application of a screw attaching the ACP to the strut graft to determine whether the additional screw enhanced stability in any mode of loading.

Methods

Nondestructive repeated-measures in vitro flexibility tests were performed in human cadaveric cervical spines. Nonconstraining pure moments of up to 1.5 Nm were applied while recording three-dimensional angular motion stereophotogrammetrically at each level from C4–5 to C7—T1. Nine specimens underwent the three-level corpectomy/strut graft procedure and eight specimens the two-level corpectomy/discectomy strut graft procedure. Failures during testing eliminated two of the former specimens and three of the latter specimens from analysis.

The construct applied after the two-level procedure allowed a significantly smaller normalized neutral zone during flexion—extension than the three-level construct (p = 0.04). Normalized elastic zone and range of motion were consistently smaller in the two- than in the three-level construct, but the differences were not significant. Addition of a screw to the strut graft significantly reduced motion in the three-level procedure—treated specimens during flexion and lateral bending but had no effect on two-level corpectomy—treated specimens.

Conclusions

The construct associated with the two-level corpectomy/discectomy provided better immediate postoperative stability than that associated with the three-level corpectomy. The addition of a screw to the strut graft conferred stability on the three-level construct but not the two-level construct.