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Item Techniques for placement of grid and strip electrodes for intracranial epilepsy surgery monitoring: Pearls and pitfalls(Scientific Scholar, 2013-07-26) Voorhies, Jason M.; Cohen‑Gadol, Aaron; Neurological Surgery, School of MedicineBackground: Placement of intracranial strip and grid electrodes for recording cortical electrocorticography is important as part of the workup of patients who are being considered for resective epilepsy surgery. In recent decades, the indications and techniques for intracranial epilepsy monitoring have been refined. Methods: In this article, the authors describe the techniques for intraoperative placement of grid and strip electrodes for extraoperative study of a seizure focus. Results: Methods to enhance the efficacy of this technique while minimizing complications are reviewed. Conclusions: Intracranial epilepsy monitoring with grid and strip electrodes is a useful tool for the planning of resective epilepsy surgery. Techniques to advance the safety and minimize complications will lead to improved outcomes.Item Characterizing Calcium Influx Via Voltage- and Ligand-Gated Calcium Channels in Embryonic Alligator Neurons in Culture(De Gruyter, 2013) Ju, Weina; Wu, Jiang; Pritz, Michael B.; Khanna, Rajesh; Neurological Surgery, School of MedicineVertebrate brains share many features in common. Early in development, both the hindbrain and diencephalon are built similarly. Only later in time do differences in morphology occur. Factors that could potentially influence such changes include certain physiological properties of neurons. As an initial step to investigate this problem, embryonic Alligator brain neurons were cultured and calcium responses were characterized. The present report is the first to document culture of Alligator brain neurons in artificial cerebrospinal fluid (ACSF) as well as in standard mammalian tissue culture medium supplemented with growth factors. Alligator brain neuron cultures were viable for at least 1 week with unipolar neurites emerging by 24 hours. Employing Fura-2 AM, robust depolarization-induced calcium influx, was observed in these neurons. Using selective blockers of the voltage-gated calcium channels, the contributions of N-, P/Q-, R-, T-, and L-type channels in these neurons were assessed and their presence documented. Lastly, Alligator brain neurons were challenged with an excitotoxic stimulus (glutamate + glycine) where delayed calcium deregulation could be prevented by a classical NMDA receptor antagonist.Item Systematic Review and Meta-Analysis of Endovascular Therapy Effectiveness for Unruptured Saccular Intracranial Aneurysms(American Heart Association, 2024) Pineda-Castillo, Sergio A.; Jones, Evan R.; Laurence, Keely A.; Thoendel, Lauren R.; Cabaniss, Tanner L.; Zhao, Yan D.; Bohnstedt, Bradley N.; Lee, Chung-Hao; Neurological Surgery, School of MedicineBackground: Currently, endovascular treatment of intracranial aneurysms (ICAs) is limited by low complete occlusion rates. The advent of novel endovascular technology has expanded the applicability of endovascular therapy; however, the superiority of novel embolic devices over the traditional Guglielmi detachable coils (GDCs) is still debated. We performed a systematic review of literature that reported Raymond-Roy occlusion classification (RROC) rates of modern endovascular devices to determine their immediate and follow-up occlusion effectiveness for the treatment of unruptured saccular ICAs. Methods: A search was conducted using electronic databases (PUBMED, Cochrane, ClinicalTrials.gov, Web of Science). We retrieved studies published between 2000-2022 reporting immediate and follow-up RROC rates of subjects treated with different endovascular ICA therapies. We extracted demographic information of the treated patients and their reported angiographic RROC rates. Results: A total of 80 studies from 15 countries were included for data extraction. RROC rates determined from angiogram were obtained for 21,331 patients (72.5% females, pooled mean age: 58.2 (95% CI: 56.8-59.6), harboring 22,791 aneurysms. The most frequent aneurysm locations were the internal carotid artery (46.4%, 95% CI: 41.9%-50.9%), the anterior communicating artery (26.4%, 95% CI: 22.5%-30.8%), the middle cerebral artery (24.5%, 95% CI:19.2%-30.8%) and the basilar tip (14.4%, 95% CI:11.3%-18.3%). The complete occlusion probability (RROC-I) was analyzed for GDCs, the Woven EndoBridge (WEB), and flow diverters. The RROC-I rate was the highest in balloon-assisted coiling (73.9%, 95% CI: 65.0%-81.2%) and the lowest in the WEB (27.8%, 95% CI:13.2%-49.2%). The follow-up RROC-I probability was homogenous in all analyzed devices. Conclusions: We observed that the coil-based endovascular therapy provides acceptable rates of complete occlusion, and these rates are improved in balloon-assisted coils. Out of the analyzed devices, the WEB exhibited the shortest time to achieve >90% probability of follow-up complete occlusion (~18 months). Overall, the GDCs remain the gold standard for endovascular treatment of unruptured saccular aneurysms.Item The Remote Intradural Migration of Polyethylene Glycol-Based Hydrogel Sealant Following Lumbar Laminectomy: A Case Report(MDPI, 2025-02-22) Obeng-Gyasi, Barnabas; Line, Trenton A.; Brown, Whitney; Chinthala, Anoop S.; Kussow, Nathan J.; Mao, Gordon; Neurological Surgery, School of MedicineBackground/Objectives: Synthetic polyethylene glycol (PEG)-based hydrogel sealants, such as Adherus, are commonly used in spinal surgeries to achieve watertight dural closure and prevent cerebrospinal fluid (CSF) leaks. This case report describes an unusual instance of suspected hydrogel sealant migration resulting in an intradural collection at a spinal level remote from the original surgery. Methods: A 57-year-old female with a history of osteoarthritis and prediabetes underwent a minimally invasive L5-S1 laminectomy for the removal of an epidural abscess causing cauda equina and S1 nerve root compression. During the procedure, a dural puncture occurred, which was repaired using Duragen (collagen matrix) and Adherus (synthetic PEG hydrogel sealant). Postoperatively, the patient developed urinary retention and new bilateral posterior leg pain. An MRI on postoperative day four revealed a new peripherally enhancing dorsal intradural collection at the L2 level, causing significant thecal sac narrowing and compression of the cauda equina nerve roots, suggestive of migration of the hydrogel sealant used during surgery. Conservative management was adopted. Results: The patients symptoms gradually resolved. Follow-up imaging at five months showed resolution of the intradural collection, with residual intradural inflammatory changes and arachnoiditis. Conclusions: While PEG-based hydrogel sealants like Adherus are effective in preventing CSF leaks, they can, in rare instances, migrate and cause remote intradural collections with neurological symptoms. Surgeons should exercise meticulous application techniques, thoroughly document the use of sealants, and maintain vigilant postoperative monitoring to mitigate these risks.Item Multi-omics analysis identifies glioblastoma dependency on H3K9me3 methyltransferase activity(Springer Nature, 2025-03-20) Xie, Qiqi; Du, Yuanning; Ghosh, Sugata; Rajendran, Saranya; Cohen-Gadol, Aaron A.; Baizabal, José-Manuel; Nephew, Kenneth P.; Han, Leng; Shen, Jia; Neurological Surgery, School of MedicineHistone H3 lysine 9 dimethylation and trimethylation (H3K9me2/3) are prevalent in human genomes, especially in heterochromatin and specific euchromatic genes. Methylation of H3K9 is modulated by enzymes such as SUV39H1, SUV39H2, SETDB1, SETDB2, and EHMT1/2, which influence cancer progression. This study reveals differential expression of these six H3K9 methyltransferases in tumors, with SUV39H1, SUV39H2, and SETDB1 showing significant links to cancer phenotypes. We developed the “H3K9me3 MtSig” (H3K9me3 methyltransferases signature) based on these findings. H3K9me3 MtSig is unique to various tumors, with prognostic significance and associations with key signaling pathways, especially in glioblastoma (GBM). Elevated H3K9me3 MtSig was observed in GBM samples, correlating with the G2/M cell cycle and reduced immune responses. H3K9me3-mediated repetitive sequence silencing by H3K9me3 MtSig contributed to these phenotypes, and inhibiting H3K9me3 MtSig in patient-derived GBM cells suppressed proliferation and increased immune responses. H3K9me3 MtSig serves as an independent prognostic factor and potential therapeutic target.Item Editorial for Brain Sciences Special Issue “Advances in Restorative Neurotherapeutic Technologies”(MDPI, 2025-03-05) Line, Trenton A.; Elkinbard, Isabella S.; Purger, David A.; Buch, Vivek P.; Neurological Surgery, School of MedicineItem Efficacy of postoperative seizure prophylaxis in intra-axial brain tumor resections(Springer, 2014) Ansari, Shaheryar F.; Bohnstedt, Bradley N.; Perkins, Susan M.; Althouse, Sandra K.; Miller, James C.; Neurological Surgery, School of MedicineThe effectiveness of seizure prophylaxis in controlling postoperative seizures following craniotomy for tumor resection is unclear. Most patients are seizure-free before surgery. To prevent seizures, it is common to treat tumor craniotomy patients postoperatively with an antiepileptic drug (AED). The authors retrospectively analyzed seizure occurrence with and without postoperative prophylactic AEDs. Between 2005 and 2011 at the authors' institution, 588 patients underwent craniotomy for brain tumors and were screened. Data on seizures, AED use, histopathology, comorbidities, complications, and follow-up were collected. Exclusion criteria included lack of follow-up data, previous operation, preoperative seizures, or preoperative AED prophylaxis. The incidence of postoperative seizures in patients with and without prophylactic AEDs was compared using logistic regression analysis. A total of 202 patients (50.5% female) were included. The most common tumor diagnosis was metastasis (42.6%). Of the 202 patients, 66.3% were prescribed prophylactic AED after surgery. Forty-six of 202 (22.8%) suffered a postoperative seizure. The odds of seizure for patients on prophylactic AED was 1.62 times higher than those not on AED (p = 0.2867). No difference was found in seizure occurrence between patients with glioblastoma multiforme compared with other tumor types (odds ratio 1.75, p = 0.1468). No difference was found in time-to-seizure between the two groups (hazard ratio 1.38, p = 0.3776). These data show no statistically significant benefit to prophylactic postoperative AED and a nonsignificant trend for increased seizure risk with AEDs. A randomized, placebo-controlled trial is needed to clarify the benefit of postoperative AED use for brain tumor resection.Item The extended supracerebellar transtentorial approach for resection of medial tentorial meningiomas(Scientific Scholar, 2014-03-15) Ansari, Shaheryar F.; Young, Ronald L.; Bohnstedt, Bradley N.; Cohen‑Gadol, Aaron A.; Neurological Surgery, School of MedicineBackground: The supracerebellar transtentorial (SCTT) approach has been established as a safe corridor to access the posteriomedial basal temporal region. Previous reports have demonstrated the efficacy of this route in the resection of intrinsic tumors and small arteriovenous malformations. Only one report in the English literature has described its use to resect a medial tentorial meningioma. Methods: The authors discuss the relevant surgical anatomy of this approach and its advantages compared with more traditional routes, and illustrate its application to remove medial tentorial meningiomas through two operative cases with accompanying videos. Results: In illustrative case one, the patient recovered from surgery with no deficits. All his preoperative symptoms had resolved at 3-month follow-up. At the 4-year follow-up, MRI did not demonstrate any growth of the residual tumor. In case two, gross total resection was achieved and the patient did not suffer any postoperative language or visual deficit. At 2-year follow-up, no tumor recurrence was present. Conclusion: The SCTT approach has a potential to safely access extra-axial lesions located around the medial tentorial incisura. As demonstrated in these two cases, the approach merits consideration in patients with tentorial meningiomas as an alternative to more widely utilized skull base approaches and subtemporal routes.Item Surgical decompression in acute spinal cord injury: A review of clinical evidence, animal model studies, and potential future directions of investigation(Frontiers Media, 2014) Li, Yiping; Walker, Chandler L.; Zhang, Yi Ping; Shields, Christopher B.; Xu, Xiao-Ming; Neurological Surgery, School of MedicineThe goal for treatment in acute spinal cord injury (SCI) is to reduce the extent of secondary damage and facilitate neurologic regeneration and functional recovery. Although multiple studies have investigated potential new therapies for the treatment of acute SCI, outcomes and management protocols aimed at ameliorating neurologic injury in patients remain ineffective. More recent clinical and basic science research have shown surgical interventions to be a potentially valuable modality for treatment; however, the role and timing of surgical decompression, in addition to the optimal surgical intervention, remain one of the most controversial topics pertaining to surgical treatment of acute SCI. As an increasing number of potential treatment modalities emerge, animal models are pivotal for investigating its clinical application and translation into human trials. This review critically appraises the available literature for both clinical and basic science studies to highlight the extent of investigation that has occurred, specific therapies considered, and potential areas for future research.Item A brief review of recent advances in stem cell biology(Wolters Kluwer, 2014) Chen, Jinhui; Zhou, Libing; Pan, Su-yue; Neurological Surgery, School of MedicineStem cells have the remarkable potential to develop into many different cell types, essentially without limit to replenish other cells as long as the person or animal is still alive, offering immense hope of curing Alzheimer's disease, repairing damaged spinal cords, treating kidney, liver and lung diseases and making damaged hearts whole. Until recently, scientists primarily worked with two kinds of stem cells from animals and humans: embryonic stem cells and non-embryonic "somatic" or "adult" stem cells. Recent breakthrough make it possible to convert or "reprogram" specialized adult cells to assume a stem stem-like cells with different technologies. The review will briefly discuss the recent progresses in this area.