bluuebunny/crossref_metadata_2025 huggingface dataset:
Feasibility and safety of intraoperative BOLD functional MRI cerebrovascular reactivity to evaluate extracranial-to-intracranial bypass efficacy
Authors: Muscas Giovanni , Bas van Niftrik Christiaan Hendrik , Fierstra Jorn , Piccirelli Marco , Sebök Martina , Burkhardt Jan-Karl , Valavanis Antonios , Pangalu Athina , Regli Luca , Bozinov Oliver
Published: February 2019

Blood oxygenation level–dependent functional MRI cerebrovascular reactivity (BOLD-CVR) is a contemporary technique to assess brain tissue hemodynamic changes after extracranial- intracranial (EC-IC) bypass flow augmentation surgery. The authors conducted a preliminary study to investigate the feasibility and safety of intraoperative 3-T MRI BOLD-CVR after EC-IC bypass flow augmentation surgery. Five consecutive patients selected for EC-IC bypass revascularization underwent an intraoperative BOLD-CVR examination to assess early hemodynamic changes after revascularization and to confirm the safety of this technique. All patients had a normal postoperative course, and none of the patients exhibited complications or radiological alterations related to prolonged anesthesia time. In addition to intraoperative flow measurements of the bypass graft, BOLD-CVR maps added information on the hemodynamic status and changes at the brain tissue level. Intraoperative BOLD-CVR is feasible and safe in patients undergoing EC-IC bypass revascularization. This technique can offer immediate hemodynamic feedback on brain tissue revascularization after bypass flow augmentation surgery.
Role of botulinum neurotoxin–A in cerebral revascularization graft vasospasm prevention: current state of knowledge
Authors: Ravina Kristine , Strickland Ben A. , Rennert Robert C. , Carey Joseph N. , Russin Jonathan J.
Published: February 2019

Graft stenosis and occlusion remain formidable complications in cerebral revascularization procedures, which can lead to significant morbidity and mortality. Graft vasospasm can result in early postoperative graft stenosis and occlusion and is believed to be at least partially mediated through adrenergic pathways. Despite various published treatment protocols, there is no single effective spasmolytic agent. Multiple factors, including anatomical and physiological variability in revascularization conduits, patient age, and comorbidities, have been associated with graft vasospasm pathogenesis and response to spasmolytics. The ideal spasmolytic agent thus likely needs to target multiple pathways to exert a generalizable therapeutic effect. Botulinum toxin (BTX)–A is a powerful neurotoxin widely used in clinical practice for the treatment of a variety of spastic conditions. Although its commonly described paradigm of cholinergic neural transmission blockade has been widely accepted, evidence for other mechanisms of action including inhibition of adrenergic transmission have been described in animal studies. Recently, the first pilot study demonstrating clinical use of BTX-A for cerebral revascularization graft spasm prevention has been reported. In this review, the mechanistic basis and potential future clinical role of BTX-A in graft vasospasm prevention is discussed.
Urinary incontinence following deep brain stimulation of the globus pallidus internus: case report
Authors: Liu Feng-Tao , Lang Li-Qin , Zhou Ren-Yuan , Feng Rui , Hu Jie , Wang Jian , Wu Jian-Jun
Published: February 2019

Deep brain stimulation (DBS) is a well-established therapy for patients with advanced Parkinson’s disease (PD), dystonia, and other movement disorders. In contrast to the strong positive effects that have been documented for motor symptoms, the effects of DBS on nonmotor symptoms have not been fully elucidated. Some reports suggest that stimulation of the subthalamic nucleus may improve lower urinary tract symptoms in patients with PD; however, reports of the effects of globus pallidus internus (GPi) DBS on urinary symptoms are limited. The authors present the case of a 49-year-old woman with PD who developed severe urinary incontinence after 27 months of GPi DBS. The urinary incontinence disappeared when stimulation was turned off, and reemerged after it was turned on again. After activation of a more dorsal contact in the left electrode, the patient’s urinary dynamics returned to normal.
Prediction of postoperative deficits using an improved diffusion-weighted imaging maximum a posteriori probability analysis in pediatric epilepsy surgery
Authors: Lee Min-Hee , O’Hara Nolan B. , Nakai Yasuo , Luat Aimee F. , Juhasz Csaba , Sood Sandeep , Asano Eishi , Jeong Jeong-Won
Published: February 2019

OBJECTIVE

This study is aimed at improving the clinical utility of diffusion-weighted imaging maximum a posteriori probability (DWI-MAP) analysis, which has been reported to be useful for predicting postoperative motor, language, and visual field deficits in pediatric epilepsy surgery. The authors determined the additive value of a new clustering mapping method in which average direct-flip distance (ADFD) reclassifies the outliers of original DWI-MAP streamlines by referring to their minimum distances to the exemplar streamlines (i.e., medoids).

METHODS

The authors studied 40 children with drug-resistant focal epilepsy (mean age 8.7 ± 4.8 years) who had undergone resection of the presumed epileptogenic zone and had five categories of postoperative deficits (i.e., hemiparesis involving the face, hand, and/or leg; dysphasia requiring speech therapy; and/or visual field cut). In pre- and postoperative images of the resected hemisphere, DWI-MAP identified a total of nine streamline pathways: C1 = face motor area, C2 = hand motor area, C3 = leg motor area, C4 = Broca’s area–Wernicke’s area, C5 = premotor area–Broca’s area, C6 = premotor area–Wernicke’s area, C7 = parietal area–Wernicke’s area, C8 = premotor area–parietal area, and C9 = occipital lobe–lateral geniculate nucleus. For each streamline of the identified pathway, the minimal ADFD to the nine exemplars corrected the pathway membership. Binary logistic regression analysis was employed to determine how accurately two fractional predictors, Δ1–9 (postoperative volume change of C1–9) and γ1–9 (preoperatively planned volume of C1–9 resected), predicted postoperative motor, language, and visual deficits.

RESULTS

The addition of ADFD to DWI-MAP analysis improved the sensitivity and specificity of regression models for predicting postoperative motor, language, and visual deficits by 28% for Δ1–3 (from 0.62 to 0.79), 13% for Δ4–8 (from 0.69 to 0.78), 13% for Δ9 (from 0.77 to 0.87), 7% for γ1–3 (from 0.81 to 0.87), 1% for γ4–8 (from 0.86 to 0.87), and 24% for γ9 (from 0.75 to 0.93). Preservation of the eloquent pathways defined by preoperative DWI-MAP analysis with ADFD (up to 97% of C1–4,9) prevented postoperative motor, language, and visual deficits with sensitivity and specificity ranging from 88% to 100%.

CONCLUSIONS

The present study suggests that postoperative functional outcome substantially differs according to the extent of resected white matter encompassing eloquent cortex as determined by preoperative DWI-MAP analysis. The preservation of preoperative DWI-MAP–defined pathways may be crucial to prevent postoperative deficits. The improved DWI-MAP analysis may provide a complementary noninvasive tool capable of guiding the surgical margin to minimize the risk of postoperative deficits for children.
Embolization of cerebral arteriovenous shunts in infants weighing less than 5 kg
Authors: Puccinelli Francesco , Tran Dong Minh Ngoc Thien Kim , Iacobucci Marta , Mazoit Jean-Xavier , Durand Philippe , Tissieres Pierre , Saliou Guillaume
Published: February 2019

OBJECTIVE

Endovascular treatment in children, especially neonates, can be more challenging than analogous procedures in adults. This study aimed to describe the clinical and radiological findings, type and timing of endovascular treatment, and early outcomes in children who present with neurovascular malformations, who are treated with embolization, and who weigh less than 5 kg.

METHODS

The authors carried out a retrospective review of all consecutively treated children weighing less than 5 kg with neurovascular arteriovenous malformations (AVMs) at a single institution over a 10-year period.

RESULTS

Fifty-two patients were included in the study. Thirty-eight had a vein of Galen aneurysmal malformation, 3 a pial AVM, 6 a pial arteriovenous fistula, and 5 a dural sinus malformation. The endovascular treatment goals were control of cardiac failure or hydrocephalus in cases of nonhemorrhagic malformations or to prevent new bleeding in cases of previous hemorrhage. A hemorrhagic complication occurred in 12 procedures and an ischemic complication in 2. Both complication types were correlated with the age of the infant (age cutoff at 3 months) (p = of 0.015 and 0.049, respectively). No correlation was found with the weight of the infant or the duration of the procedure.

CONCLUSIONS

The embolization of AVMs in these patients prevented adverse cardiac effects, hydrovenous disorders, and rebleeding. The risk of major cerebral complications seems mainly correlated with age, with a threshold at 3 months. A multidisciplinary team involved in the treatment of these children may help to improve treatment success and management.
Somatotopic organization of the human spinothalamic tract: in vivo computed tomography–guided mapping in awake patients undergoing cordotomy
Authors: Honey C. Michael , Ivanishvili Zurab , Honey Christopher R. , Heran Manraj K. S.
Published: February 2019

OBJECTIVE

The location of the human spinothalamic tract (STT) in the anterolateral spinal cord has been known for more than a century. The exact nature of the neuronal fiber lamination within the STT, however, remains controversial. After correlating in vivo macrostimulation-induced pain/temperature sensation during percutaneous cervical cordotomy with simultaneous CT imaging of the electrode tip location, the authors present a modern description of the somatotopy of the human cervical STT.

METHODS

Twenty patients underwent CT-guided percutaneous cervical cordotomy to alleviate contralateral medication-refractory cancer pain. Patient responses to electrical stimulation (0.01–0.1 V, 50 Hz, 1 msec) were recorded and the electrode location for each response was documented with a contemporaneous CT scan. In a post hoc analysis of the data, the location for each patient’s response(s) was measured and drawn on a diagram of their cord. Positive responses were represented only when the lowest possible voltage (≤ 0.02 V) elicited a response. Negative responses were recorded if there was no clinical response at 0.1 V.

RESULTS

Clinically, patients did well with an average reduction in opiates of 75% at 1 week, and 67% were able to leave the palliative care unit. The size of the cervical cord varied between patients, with an average lateral extent (width) of 11 mm and a height of 9 mm. Responses from the lower limb were represented superficially (lateral) and posteriorly within the anterolateral cord. The area with responses from the upper limb was larger and surrounded those with responses from the lower limb primarily anteriorly and medially, but also posteriorly.

CONCLUSIONS

In this study, the somatotopic organization of the human STT was elucidated for the first time using in vivo macrostimulation and contemporaneous CT imaging during cordotomy. In this cohort of patients, the STT from the lower-limb region was located superficially and posteriorly in the anterolateral quadrant of the cervical cord, with the STT from the upper-limb region surrounding it primarily anteriorly and medially (deep) but also posteriorly. The authors discuss how the previous methods of cordotomy may have biased the earlier versions of STT lamination. They suggest that an ideal spinal cord entry site for cordotomy of either the upper- or lower-limb pain fibers is halfway between the equator and anterior pole of the cord.
Radiosurgery for multiple sclerosis–related trigeminal neuralgia: retrospective review of long-term outcomes
Authors: Przybylowski Colin J. , Cole Tyler S. , Baranoski Jacob F. , Little Andrew S. , Smith Kris A. , Shetter Andrew G.
Published: February 2019

OBJECTIVE

The objective of this study was to assess long-term outcomes of facial pain and numbness after radiosurgery for multiple sclerosis (MS)–related trigeminal neuralgia (MS-TN).

METHODS

The authors conducted a retrospective review of their Gamma Knife radiosurgeries (GKRSs) to identify all patients treated for MS-TN (1998–2014) with at least 3 years of follow-up. Treatment and clinical data were obtained via chart review and mailed or telephone surveys. Pain control was defined as a facial pain score of I–IIIb on the Barrow Neurological Institute (BNI) Facial Pain Intensity Scale. Kaplan-Meier analysis was performed to determine the rates of pain control after index and first salvage GKRS procedures. Patients could have had more than 1 salvage procedure. Pain control rates were based on the number of patients at risk during follow-up.

RESULTS

Of the 50 living patients who underwent GKRS, 42 responded to surveys (31 women [74%], median age 59 years, range 32–76 years). During the initial GKRS, the trigeminal nerve root entry zone was targeted with a single isocenter, using a 4-mm collimator with the 90% isodose line completely covering the trigeminal nerve and the 50% isodose line abutting the surface of the brainstem. The median maximum radiation dose was 85 Gy (range 50–85 Gy). The median follow-up period was 78 months (range 36–226 months). The rate of pain control after the index GKRS (n = 42) was 62%, 29%, 22%, and 13% at 1, 3, 5, and 7 years, respectively. Twenty-eight patients (67%) underwent salvage treatment, including 25 (60%) whose first salvage treatment was GKRS. The rate of pain control after the first salvage GKRS (n = 25) was 84%, 50%, 44%, and 17% at 1, 3, 5, and 7 years, respectively. The rate of pain control after the index GKRS with or without 1 salvage GKRS (n = 33) was 92%, 72%, 52%, 46%, and 17% at 1, 3, 5, 7, and 10 years, respectively. At last follow-up, 9 (21%) of the 42 patients had BNI grade I facial pain, 35 (83%) had achieved pain control, and 4 (10%) had BNI grade IV facial numbness (very bothersome in daily life).

CONCLUSIONS

Index GKRS offers good short-term pain control for MS-TN, but long-term pain control is uncommon. If the index GKRS fails, salvage GKRS appears to offer beneficial pain control with low rates of bothersome facial numbness.
Surgical outcomes after reoperation for recurrent non–skull base meningiomas
Authors: Magill Stephen T. , Dalle Ore Cecilia L. , Diaz Michael A. , Jalili Daara D. , Raleigh David R. , Aghi Manish K. , Theodosopoulos Philip V. , McDermott Michael W.
Published: February 2019

OBJECTIVE

Recurrent meningiomas are primarily managed with radiation therapy or repeat resection. Surgical morbidity after reoperation for recurrent meningiomas is poorly understood. Thus, the objective of this study was to report surgical outcomes after reoperation for recurrent non–skull base meningiomas.

METHODS

A retrospective review of patients was performed. Inclusion criteria were patients with recurrent meningioma who had prior resection and supratentorial non–skull base location. Univariate and multivariate logistic regression and recursive partitioning analysis were used to identify risk factors for surgical complications.

RESULTS

The authors identified 67 patients who underwent 111 reoperations for recurrent supratentorial non–skull base meningiomas. The median age was 53 years, 49% were female, and the median follow-up was 9.8 years. The most common presenting symptoms were headache, weakness, and seizure. The WHO grade after the last reoperation was grade I in 22% of cases, grade II in 51%, and grade III in 27%. The tumor grade increased at reoperation in 22% of cases. Tumors were located on the convexity (52%), parasagittal (33%), falx (31%), and multifocal (19%) locations. Tumors involved the middle third of the sagittal plane in 52% of cases. In the 111 reoperations, 48 complications occurred in 32 patients (48%). There were 26 (54%) complications requiring surgical intervention. There was no perioperative mortality. Complications included neurological deficits (14% total, 8% permanent), wound dehiscence/infection (14%), and CSF leak/pseudomeningocele/hydrocephalus (9%). Tumors that involved the middle third of the sagittal plane (OR 6.97, 95% CI 1.5–32.0, p = 0.006) and presentation with cognitive changes (OR 20.7, 95% CI 2.3–182.7, p = 0.001) were significantly associated with complication occurrence on multivariate analysis. The median survival after the first reoperation was 11.5 years, and the 2-, 5-, and 10-year Kaplan-Meier survival rates were 91.0%, 68.8%, and 50.0%, respectively.

CONCLUSIONS

Reoperation for recurrent supratentorial non–skull base meningioma is associated with a high rate of complications. Patients with cognitive changes and tumors that overlap the middle third of the sagittal plane are at increased risk of complications. Nevertheless, excellent long-term survival can be achieved without perioperative mortality.
Influence of pretreatment growth rate on Gamma Knife treatment response for vestibular schwannoma: a volumetric analysis
Authors: Langenhuizen Patrick P. J. H. , Zinger Svitlana , Hanssens Patrick E. J. , Kunst Henricus P. M. , Mulder Jef J. S. , Leenstra Sieger , de With Peter H. N. , Verheul Jeroen B.
Published: February 2019

OBJECTIVE

The aim of this study was to gain insight into the influence of the pretreatment growth rate on the volumetric tumor response and tumor control rates after Gamma Knife radiosurgery (GKRS) for incidental vestibular schwannoma (VS).

METHODS

All patients treated with GKRS at the Gamma Knife Center, ETZ Hospital, who exhibited a confirmed radiological progression of their VS after an initial observation period were included. Pre- and posttreatment MRI scans were volumetrically evaluated, and the volume doubling times (VDTs) prior to treatment were calculated. Posttreatment volumes were used to create an objective mathematical failure definition: 2 consecutive significant increases in tumor volume among 3 consecutive follow-up MRI scans. Spearman correlation, Kaplan-Meier survival analysis, and Cox proportional hazards regression analysis were used to determine the influence of the VDT on the volumetric treatment response.

RESULTS

The resulting patient cohort contained 311 patients in whom the VDT was calculated. This cohort had a median follow-up time of 60 months after GKRS. Of these 311 patients, 35 experienced loss of tumor control after GKRS. The pretreatment growth rate and the relative volume changes, calculated at 6 months and 1, 2, and 3 years following treatment, showed no statistically significant correlation. Kaplan-Meier analysis revealed that slow-growing tumors, with a VDT equal to or longer than the median VDT of 15 months, had calculated 5- and 10-year control rates of 97.3% and 86.0%, respectively, whereas fast-growing tumors, with a VDT less than the median growth rate, had control rates of 85.5% and 67.6%, respectively (log-rank, p = 0.001). The influence of the VDT on tumor control was also determined by employing the Cox regression analysis. The resulting model presented a significant (p = 0.045) effect of the VDT on the hazard rates of loss of tumor control.

CONCLUSIONS

By employing a unique, large database with long follow-up times, the authors were able to accurately investigate the influence of the pretreatment VS growth rate on the volumetric GKRS treatment response. The authors have found a predictive model that illustrates the negative influence of the pretreatment VS growth rate on the efficacy of radiosurgery treatment. The resulting tumor control rates confirm the high efficacy of GKRS for slow-growing VS. However, fast-growing tumors showed significantly lower control rates. For these cases, different treatment strategies may be considered.
Aneurysm rebleeding before therapy: a predictable disaster?
Authors: Darkwah Oppong Marvin , Gümüs Meltem , Pierscianek Daniela , Herten Annika , Kneist Andreas , Wrede Karsten , Barthel Lennart , Forsting Michael , Sure Ulrich , Jabbarli Ramazan
Published: February 2019

OBJECTIVE

Current guidelines for subarachnoid hemorrhage (SAH) include early aneurysm treatment within 72 hours after ictus. However, aneurysm rebleeding remains a crucial complication of SAH. The aim of this study was to identify independent predictors allowing early stratification of SAH patients for rebleeding risk.

METHODS

All patients admitted to the authors’ institution with ruptured aneurysms during a 14-year period were eligible for this retrospective study. Demographic and radiographic parameters, aneurysm characteristics, medical history, and medications as well as baseline parameters at admission (blood pressure and laboratory parameters) were evaluated in univariate and multivariate analyses. A novel risk score was created using independent risk factors.

RESULTS

Data from 984 cases could be included into the final analysis. Aneurysm rebleeding occurred in 58 cases (5.9%), and in 48 of these cases (82.8%) rerupture occurred within 24 hours after SAH. Of over 30 tested associations, preexisting arterial hypertension (p = 0.02; adjusted odds ratio [aOR] 2.56, 1 score point), aneurysm location at the basilar artery (p = 0.001, aOR 4.5, 2 score points), sac size ≥ 9 mm (p = 0.04, aOR 1.9, 1 score point), presence of intracerebral hemorrhage (p = 0.001, aOR 4.29, 2 score points), and acute hydrocephalus (p < 0.001, aOR 6.27, 3 score points) independently predicted aneurysm rebleeding. A score built upon these parameters (0–9 points) showed a good diagnostic accuracy (p < 0.001, area under the curve 0.780) for rebleeding prediction.

CONCLUSIONS

Certain patient-, aneurysm-, and SAH-specific parameters can reliably predict aneurysm rerupture. A score developed according to these parameters might help to identify individuals that would profit from immediate aneurysm occlusion.
Blast-induced traumatic brain injury: the experience from a level I trauma center in southern Thailand
Authors: Tunthanathip Thara , Khocharoen Kanutpon , Phuenpathom Nakornchai
Published: February 2019

OBJECTIVE

In the ongoing conflict in southern Thailand, the improvised explosive device (IED) has been a common cause of blast-induced traumatic brain injury (bTBI). The authors investigated the particular characteristics of bTBI and the factors associated with its clinical outcome.

METHODS

A retrospective cohort study was conducted on all patients who had sustained bTBI between 2009 and 2017. Collected data included clinical characteristics, intracranial injuries, and outcomes. Factors analysis was conducted using a forest plot.

RESULTS

During the study period, 70 patients met the inclusion criteria. Fifty individuals (71.4%) were military personnel. One-third of the patients (32.9%) suffered moderate to severe bTBI, and the rate of intracerebral injuries on brain CT was 65.7%. Coup contusion was the most common finding, and primary blast injury was the most common mechanism of blast injury. Seventeen individuals had an unfavorable outcome (Glasgow Outcome Scale score 1–3), and the overall mortality rate for bTBI was 11.4%. In the univariate analysis, factors associated with an unfavorable outcome were preoperative coagulopathy, midline shift of the brain ≥ 5 mm, basal cistern effacement, moderate to severe TBI, hypotension, fixed and dilated pupils, surgical site infection, hematocrit < 30% on admission, coup contusion, and subdural hematoma. In the multivariable analysis, midline shift ≥ 5 mm (OR 29.1, 95% CI 2.5–328.1) and coagulopathy (OR 28.7, 95% CI 4.5–180.3) were the only factors predicting a poor outcome of bTBI.

CONCLUSIONS

bTBIs range from mild to severe. Midline shift and coagulopathy are treatable factors associated with an unfavorable outcome. Hence, in cases of bTBI, reversing an abnormal coagulogram is required as soon as possible to improve clinical outcomes. The management of brain shift needs further study.
Elective neurosurgical humanitarian care in a deployed setting
Authors: Forbes Jonathan A.
Published: February 2019

OBJECTIVE

Active-duty neurosurgical coverage has been provided at Bagram Air Force Base in Afghanistan since 2007. Early operative logs were reflective of a large number of surgical procedures performed to treat battlefield injuries. However, with maturation of the war effort, the number of operations for battlefield injuries has decreased with time. Consequently, procedures performed for elective neurosurgical humanitarian care (NHC) increased in number and complexity prior to closure of the Korean Hospital in 2015, which resulted in effective termination of NHC at Bagram. Monthly neurosurgical caseloads for deployed personnel have dropped precipitously since this time, renewing a debate as to whether the benefits of providing elective NHC in Afghanistan outweigh the costs of such a strategy. To date, there is a paucity of information in the literature discussing the overall context of such a determination.

METHODS

The author retrospectively reviewed his personal database of all patients who underwent neurosurgical procedures at Bagram during his deployment there from April 17 to October 29, 2014. Standardized clinical parameters had been recorded in the ABNS NeuroLog system. All cases of nonelective surgical care for battlefield injuries were identified and excluded. Records of all other procedures, which represented elective NHC delivered during this period, were accessed to extract salient clinical and radiological data.

RESULTS

During the 6-month deployment, 49 patients (29 male and 20 female, age range 18 months to 63 years) were treated by the author in elective NHC. Procedures were performed for spinal degenerative disease (n = 28), cranial tumors (n = 11), pediatric conditions (n = 6), Pott’s disease (n = 2), peripheral nerve impingement (n = 1), and adult hydrocephalus (n = 1). The duration of follow-up ranged from 3 to 23 weeks. Complications referable to surgery included asymptomatic, unilateral lumbar screw fracture detected 3 months postoperatively and treated with revision of hardware (n = 1); wound infection requiring cranial flap explantation and staged cranioplasty (n = 1); and unanticipated return to the operating room for resection of residual tumor in a patient with a solitary metastatic lesion involving the mesial temporal lobe/ambient cistern (n = 1). There were no instances of postoperative neurological decline.

CONCLUSIONS

Elective NHC can be safely and effectively implemented in the deployed setting. Benefits of a military strategy that supports humanitarian care include strengthening of the bond between the US/Afghan military communities and the local civilian population as well as maintenance of skills of the neurosurgical team during the sometimes-lengthy intervals between cases in which emergent neurosurgical care is provided for treatment of battlefield injuries.
Direct enhancement of readiness for wartime critical specialties by civilian-military partnerships for neurosurgical care: residency training and beyond
Authors: Shin David H. , Hooten Kristopher G. , Sindelar Brian D. , Corliss Brian M. , Carlton William R. Y. , Carroll Christopher P. , Tomlin Jeffrey M. , Fox W. Christopher
Published: February 2019

Military neurosurgery has played an integral role in the development and innovation of neurosurgery and neurocritical care in treating battlefield injuries. It is of paramount importance to continue to train and prepare the next generation of military neurosurgeons. For the Army, this is currently primarily achieved through the military neurosurgery residency at the National Capital Consortium and through full-time out-service positions at the Veterans Affairs–Department of Defense partnerships with the University of Florida, the University of Texas–San Antonio, and Baylor University. The authors describe the application process for military neurosurgery residency and highlight the training imparted to residents in a busy academic and level I trauma center at the University of Florida, with a focus on how case variety and volume at this particular civilian-partnered institution produces neurosurgeons who are prepared for the complexities of the battlefield. Further emphasis is also placed on collaboration for research as well as continuing education to maintain the skills of nondeployed neurosurgeons. With ongoing uncertainty regarding future conflict, it is critical to preserve and expand these civilian-military partnerships to maintain a standard level of readiness in order to face the unknown with the confidence befitting a military neurosurgeon.
Topographic correlation of infarct area on CT perfusion with functional outcome in acute ischemic stroke
Authors: Haranhalli Neil , Mbabuike Nnenna , Grewal Sanjeet S. , Hasan Tasneem F. , Heckman Michael G. , Freeman William D. , Gupta Vivek , Vibhute Prasanna , Brown Benjamin L. , Miller David A. , Jahromi Babak S. , Tawk Rabih G.
Published: February 2019

OBJECTIVE

The role of CT perfusion (CTP) in the management of patients with acute ischemic stroke (AIS) remains a matter of debate. The primary aim of this study was to evaluate the correlation between the areas of infarction and penumbra on CTP scans and functional outcome in patients with AIS.

METHODS

This was a retrospective review of 100 consecutively treated patients with acute anterior circulation ischemic stroke who underwent CT angiography (CTA) and CTP at admission between February 2011 and October 2014. On CTP, the volume of ischemic core and penumbra was measured using the Alberta Stroke Program Early CT Score (ASPECTS). CTA findings were also noted, including the site of occlusion and regional leptomeningeal collateral (rLMC) score. Functional outcome was defined by modified Rankin Scale (mRS) score obtained at discharge. Associations of CTP and CTA parameters with mRS scores at discharge were assessed using multivariable proportional odds logistic regression models.

RESULTS

The median age was 67 years (range 19–95 years), and the median NIH Stroke Scale score was 16 (range 2–35). In a multivariable analysis adjusting for potential confounding variables, having an infarct on CTP scans in the following regions was associated with a worse mRS score at discharge: insula ribbon (p = 0.043), perisylvian fissure (p < 0.001), motor strip (p = 0.007), M2 (p < 0.001), and M5 (p = 0.023). A worse mRS score at discharge was more common in patients with a greater volume of infarct core (p = 0.024) and less common in patients with a greater rLMC score (p = 0.004).

CONCLUSIONS

The results of this study provide evidence that several CTP parameters are independent predictors of functional outcome in patients with AIS and have potential to identify those patients most likely to benefit from reperfusion therapy in the treatment of AIS.
The anatomic location and importance of the tibialis posterior fascicular bundle at the sciatic nerve bifurcation: report of 3 cases
Authors: Wilson Thomas J. , Maldonado Andres A. , Amrami Kimberly K. , Glazebrook Katrina N. , Moynagh Michael R. , Spinner Robert J.
Published: February 2019

The authors present the cases of 3 patients with severe injuries affecting the peroneal nerve combined with loss of tibialis posterior function (inversion) despite preservation of other tibial nerve function. Loss of tibialis posterior function is problematic, since transfer of the tibialis posterior tendon is arguably the best reconstructive option for foot drop, when available. Analysis of preoperative imaging studies correlated with operative findings and showed that the injuries, while predominantly to the common peroneal nerve, also affected the lateral portion of the tibial nerve/division near the sciatic nerve bifurcation. Sunderland’s fascicular topographic maps demonstrate the localization of the fascicular bundle subserving the tibialis posterior to the area that corresponds to the injury. This has clinical significance in predicting injury patterns and potentially for treatment of these injuries. The lateral fibers of the tibial division/nerve may be vulnerable with long stretch injuries. Due to the importance of tibialis posterior function, it may be important to perform internal neurolysis of the tibial division/nerve in order to facilitate nerve action potential testing of these fascicles, ultimately performing split nerve graft repair when nerve action potentials are absent in this important portion of the tibial nerve.
Evaluation of stereotactic radiosurgery for cerebral dural arteriovenous fistulas in a multicenter international consortium
Authors: Starke Robert M. , McCarthy David J. , Chen Ching-Jen , Kano Hideyuki , McShane Brendan , Lee John , Mathieu David , Vasas Lucas T. , Kaufmann Anthony M. , Wang Wei Gang , Grills Inga S. , Patibandla Mohana Rao , Cifarelli Christopher P. , Paisan Gabriella , Vargo John A. , Chytka Tomas , Janouskova Ladislava , Feliciano Caleb E. , Rodriguez-Mercado Rafael , Tonetti Daniel A. , Lunsford L. Dade , Sheehan Jason P.
Published: February 2019

OBJECTIVE

In this multicenter study, the authors reviewed the results obtained in patients who underwent Gamma Knife radiosurgery (GKRS) for dural arteriovenous fistulas (dAVFs) and determined predictors of outcome.

METHODS

Data from a cohort of 114 patients who underwent GKRS for cerebral dAVFs were compiled from the International Gamma Knife Research Foundation. Favorable outcome was defined as dAVF obliteration and no posttreatment hemorrhage or permanent symptomatic radiation-induced complications. Patient and dAVF characteristics were assessed to determine predictors of outcome in a multivariate logistic regression analysis; dAVF-free obliteration was calculated in a competing-risk survival analysis; and Youden indices were used to determine optimal radiosurgical dose.

RESULTS

A mean margin dose of 21.8 Gy was delivered. The mean follow-up duration was 4 years (range 0.5–18 years). The overall obliteration rate was 68.4%. The postradiosurgery actuarial rates of obliteration at 3, 5, 7, and 10 years were 41.3%, 61.1%, 70.1%, and 82.0%, respectively. Post-GRKS hemorrhage occurred in 4 patients (annual risk of 0.9%). Radiation-induced imaging changes occurred in 10.4% of patients; 5.2% were symptomatic, and 3.5% had permanent deficits. Favorable outcome was achieved in 63.2% of patients. Patients with middle fossa and tentorial dAVFs (OR 2.4, p = 0.048) and those receiving a margin dose greater than 23 Gy (OR 2.6, p = 0.030) were less likely to achieve a favorable outcome. Commonly used grading scales (e.g., Borden and Cognard) were not predictive of outcome. Female sex (OR 1.7, p = 0.03), absent venous ectasia (OR 3.4, p < 0.001), and cavernous carotid location (OR 2.1, p = 0.019) were predictors of GKRS-induced dAVF obliteration.

CONCLUSIONS

GKRS for cerebral dAVFs achieved obliteration and avoided permanent complications in the majority of patients. Those with cavernous carotid location and no venous ectasia were more likely to have fistula obliteration following radiosurgery. Commonly used grading scales were not reliable predictors of outcome following radiosurgery.
High expression of survivin independently correlates with tumor progression and mortality in patients with skull base chordomas
Authors: Ma Junpeng , Tian Kaibing , Du Jiang , Wu Zhen , Wang Liang , Zhang Junting
Published: February 2019

OBJECTIVE

The object of this study was to clarify the expression characteristics and prognostic value of survivin in skull base chordomas.

METHODS

In this retrospective study, the authors measured the expression of survivin at the mRNA level in 81 samples from 71 patients diagnosed with skull base chordomas at their hospital in the period from July 2005 to January 2015. Clinical data collection, follow-up, and survival analyses were performed, and correlations were analyzed.

RESULTS

Of the 71 patients, 50 had primary chordomas with a mean survivin expression level of 1.09; the other 21 patients had recurrent chordomas with a mean survivin expression level of 2.57, which was 2.36 times higher than the level in the primary chordoma patients (p < 0.001, Mann-Whitney U-test). In addition, an analysis of 18 paired samples derived from 9 patients showed that the expression level of survivin was 2.62 times higher in recurrent tumors than in primary tumors (p = 0.002, paired t-test). The Spearman rank correlation coefficient method showed that the expression level of survivin was positively correlated with the mean ratio of tumor signal intensity to the signal intensity of surrounding brainstem on T1-weighted sequences (RT1; rs = 0.274, p = 0.021) and was negatively correlated with the mean ratio of tumor signal intensity to the signal intensity of surrounding brainstem on T2-weighted sequences (RT2; rs = −0.389, p = 0.001). A multivariate Cox proportional-hazards model suggested that pathology (p = 0.041), survivin expression level (p = 0.018), preoperative Karnofsky Performance Status (KPS; p = 0.012), and treatment history (p = 0.009) were independent prognostic factors for tumor progression. Survivin expression level (p = 0.008), preoperative KPS (p = 0.019), tumor diameter (p = 0.027), and intraoperative blood loss (p = 0.015) were independent prognostic factors for death.

CONCLUSIONS

Survivin expression level and preoperative KPS were independent significant prognostic factors for tumor progression and death in skull base chordoma patients. Recurrent skull base chordomas and chordomas with high RT1 and low RT2 were likely to have high survivin expression. Other independent risk factors related to tumor progression included conventional pathology and treatment history, whereas additional mortality-related risk factors included larger tumor diameter and greater intraoperative blood loss.
Quality of life outcomes for brain metastasis patients treated with stereotactic radiosurgery: pre-procedural predictive factors from a prospective national registry
Authors: Sheehan Jason P. , Grills Inga , Chiang Veronica L. , Dong Huamei , Berg Arthur , Warnick Ronald E. , Kondziolka Douglas , Kavanagh Brian
Published: February 2019

OBJECTIVE

Stereotactic radiosurgery (SRS) is increasingly used for the treatment of brain metastasis. To date, most studies have focused on survival, radiological response, or surrogate quality endpoints such as Karnofsky Performance Scale status or neurocognitive indices. The current study prospectively evaluated pre-procedural factors impacting quality of life in brain metastasis patients undergoing SRS.

METHODS

Using a national, cloud-based platform, patients undergoing SRS for brain metastasis were accrued to the registry. Quality of life prior to SRS was assessed using the 5-level EQ-5D (EQ5D-L) validated tool; additionally, patient and treatment attributes were collected. Patient quality of life was assessed as part of routine follow-up after SRS. Factors predicting a difference in the aggregate EQ5D-L score or the subscores were evaluated. Pre-SRS covariates impacting changes in EQ5D-L were statistically evaluated. Statistical analyses were conducted using multivariate linear regression models.

RESULTS

EQ5D-L results were available for 116 patients. EQ5D-L improvement (average of 0.387) was noted in patients treated with earlier SRS (p = 0.000175). Worsening overall EQ5D-L (average of 0.052 per lesion) was associated with an increased number of brain metastases at the time of initial presentation (p = 0.0399). Male sex predicted a risk of worsening (average of 0.347) of the pain and discomfort subscore at last follow-up (p = 0.004205). Baseline subscores of pain/discomfort were not correlated with pain/discomfort subscores at follow-up (p = 0.604), whereas baseline subscores of anxiety/depression were strongly positively correlated with the anxiety/depression follow-up subscores (p = 0.0039).

CONCLUSIONS

After SRS, quality of life was likely to improve in patients treated early with SRS and worsen in those with a greater number of brain metastases. Sex differences appear to exist regarding pain and discomfort worsening after SRS. Those with high levels of anxiety and depression at SRS may benefit from medical treatment as this particular quality of life factor generally remains unchanged after SRS.
Glioblastoma of the cerebellopontine angle and internal auditory canal mimicking a peripheral nerve sheath tumor: case report
Authors: Takami Hirokazu , Prummer Christoph M. , Graffeo Christopher S. , Peris-Celda Maria , Giannini Caterina , Driscoll Colin L. , Link Michael J.
Published: February 2019

Glioblastoma (GBM) of the internal auditory canal (IAC) is exceedingly rare, with only 3 prior cases reported in the literature. The authors present the fourth case of cerebellopontine angle (CPA) and IAC GBM, and the first in which the lesion mimicked a vestibular schwannoma (VS) early in its natural history. A 55-year-old man presented with tinnitus, hearing loss, and imbalance. MRI identified a left IAC/CPA lesion measuring 8 mm, most consistent with a benign VS. Over the subsequent 4 months he developed facial weakness. The tumor grew remarkably to 24 mm and surgery was recommended; the main preoperative diagnosis was malignant peripheral nerve sheath tumor (MPNST). Resection proceeded via a translabyrinthine approach with resection of cranial nerves VII and VIII, followed by facial-hypoglossal nerve anastomosis. Intraoperative frozen section suggested malignant spindle cell neoplasm, but final histopathological and molecular testing confirmed the lesion to be a GBM. The authors report the first case in which absence of any brainstem interface effectively excluded a primary parenchymal tumor, in particular GBM, from the differential diagnosis. Given the dramatic differences in treatment and prognoses between malignant glioma and MPNST, this case emphasizes the importance of surgical intervention on an aggressively growing lesion, which provides both the best probability of local control and the critical tissue diagnosis.
International practice variation in postoperative imaging of chronic subdural hematoma patients
Authors: Hulsbergen Alexander F. C. , Yan Sandra C. , Stopa Brittany M. , DiRisio Aislyn , Senders Joeky T. , van Essen Max J. , van der Burgt Stéphanie M. E. , Smith Timothy R. , Gormley William B. , Broekman Marike L. D.
Published: February 2019

OBJECTIVE

The value of CT scanning after burr hole surgery in chronic subdural hematoma (CSDH) patients is unclear, and practice differs between countries. At the Brigham and Women’s Hospital (BWH) in Boston, Massachusetts, neurosurgeons frequently order routine postoperative CT scans, while the University Medical Center Utrecht (UMCU) in the Netherlands does not have this policy. The aim of this study was to compare the use of postoperative CT scans in CSDH patients between these hospitals and to evaluate whether there are differences in clinical outcomes.

METHODS

The authors collected data from both centers for 391 age- and sex-matched CSDH patients treated with burr hole surgery between January 1, 2002, and July 1, 2016, and compared the number of postoperative scans up to 6 weeks after surgery, the need for re-intervention, and postoperative neurological condition.

RESULTS

BWH patients were postoperatively scanned a median of 4 times (interquartile range [IQR] 2–5), whereas UMCU patients underwent a median of 0 scans (IQR 0–1, p < 0.001). There was no significant difference in the number of re-operations (20 in the BWH vs 27 in the UMCU, p = 0.34). All re-interventions were preceded by clinical decline and no recurrences were detected on scans performed on asymptomatic patients. Patients’ neurological condition was not worse in the UMCU than in the BWH (p = 0.43).

CONCLUSIONS

While BWH patients underwent more scans than UMCU patients, there were no differences in clinical outcomes. The results of this study suggest that there is little benefit to routine scanning in asymptomatic patients who have undergone surgical treatment of uncomplicated CSDH and highlight opportunities to make practice more efficient.
Overall survival and response to radiation and targeted therapies among patients with renal cell carcinoma brain metastases
Authors: Juloori Aditya , Miller Jacob A. , Parsai Shireen , Kotecha Rupesh , Ahluwalia Manmeet S. , Mohammadi Alireza M. , Murphy Erin S. , Suh John H. , Barnett Gene H. , Yu Jennifer S. , Vogelbaum Michael A. , Rini Brian , Garcia Jorge , Stevens Glen H. , Angelov Lilyana , Chao Samuel T.
Published: February 2019

OBJECTIVE

The object of this retrospective study was to investigate the impact of targeted therapies on overall survival (OS), distant intracranial failure, local failure, and radiation necrosis among patients treated with radiation therapy for renal cell carcinoma (RCC) metastases to the brain.

METHODS

All patients diagnosed with RCC brain metastasis (BM) between 1998 and 2015 at a single institution were included in this study. The primary outcome was OS, and secondary outcomes included local failure, distant intracranial failure, and radiation necrosis. The timing of targeted therapies was recorded. Multivariate Cox proportional-hazards regression was used to model OS, while multivariate competing-risks regression was used to model local failure, distant intracranial failure, and radiation necrosis, with death as a competing risk.

RESULTS

Three hundred seventy-six patients presented with 912 RCC BMs. Median OS was 9.7 months. Consistent with the previously validated diagnosis-specific graded prognostic assessment (DS-GPA) for RCC BM, Karnofsky Performance Status (KPS) and number of BMs were the only factors prognostic for OS. One hundred forty-seven patients (39%) received vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs). Median OS was significantly greater among patients receiving TKIs (16.8 vs 7.3 months, p < 0.001). Following multivariate analysis, KPS, number of metastases, and TKI use remained significantly associated with OS.

The crude incidence of local failure was 14.9%, with a 12-month cumulative incidence of 13.4%. TKIs did not significantly decrease the 12-month cumulative incidence of local failure (11.4% vs 14.5%, p = 0.11). Following multivariate analysis, age, number of BMs, and lesion size remained associated with local failure. The 12-month cumulative incidence of radiation necrosis was 8.0%. Use of TKIs within 30 days of SRS was associated with a significantly increased 12-month cumulative incidence of radiation necrosis (10.9% vs 6.4%, p = 0.04).

CONCLUSIONS

Use of targeted therapies in patients with RCC BM treated with intracranial SRS was associated with improved OS. However, the use of TKIs within 30 days of SRS increases the rate of radiation necrosis without improving local control or reducing distant intracranial failure. Prospective studies are warranted to determine the optimal timing to reduce the rate of necrosis without detracting from survival.
Iron concentration linked to structural connectivity in the subthalamic nucleus: implications for deep brain stimulation
Authors: Dimov Alexey , Patel Wahaj , Yao Yihao , Wang Yi , O’Halloran Rafael , Kopell Brian H.
Published: February 2019

OBJECTIVE

The objective of this study was to investigate the relationship between iron and white matter connectivity in the subthalamic nucleus (STN) in patients undergoing deep brain stimulation (DBS) of the STN for treatment of Parkinson’s disease.

METHODS

Nine Parkinson’s disease patients underwent preoperative 3T MRI imaging which included acquisition of T1-weighted anatomical images along with diffusion tensor imaging (DTI) and quantitative susceptibility mapping (QSM). MR tractography was performed for the seed voxels located within the STN, and the correlations between normalized QSM values and the STN’s connectivity to a set of a priori chosen regions of interest were assessed.

RESULTS

A strong negative correlation was found between STN connectivity and QSM intensity for the thalamus, premotor, motor, and sensory regions, while a strong positive correlation was found for frontal, putamen, and brain stem areas.

CONCLUSIONS

Quantitative susceptibility mapping not only accurately delineates the STN borders but is also able to provide functional information about the STN functional subdivisions. The observed iron-to-connectivity correlation patterns may aid in planning DBS surgery to avoid unwanted side effects associated with DBS.