Aug 2026· Journal of Neurosurgery: Case Lessons· Vol 12· 0 citations· 44 references
Medicine
TL;DR
This case highlights underrecognized perforator-related subcortical infarction after LEAT resection and suggests a possible relationship between subcortical stroke and N2 latency changes that warrants further study.
Abstract
BACKGROUND The authors present the case of a 15-year-old male who underwent resection of a left parieto-occipital long-term epilepsy-associated tumor (LEAT) near the language and visual tracts. Tractography-guided dorsal language stream cortico-cortical evoked potentials (CCEPs) and visual evoked potentials (VEPs) were used intraoperatively under general anesthesia to minimize postoperative deficits. This case report describes the utility and limitations of CCEPs, VEPs, and tractography in pediatric resective epilepsy surgery. OBSERVATIONS During resection, CCEP N1 amplitude and latency remained stable; N2 latency was prolonged by 23% (from 11.3 to 14.0 msec). VEP P100 amplitude decreased transiently by approximately 80% intraoperatively and recovered to approximately 20% below baseline at closure. Postoperative MRI showed a subcortical ischemic infarct in the occipital periventricular white matter involving the inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, and optic radiations. Postoperatively, the patient exhibited dysphasia and right homonymous hemianopia. The patient remained seizure free with improved speech at the 18-month follow-up. LESSONS Intraoperative CCEPs, VEPs, and pre- and postoperative tractography have their uses and limitations in monitoring and assessing the integrity of language/visual white matter pathways. This case highlights underrecognized perforator-related subcortical infarction after LEAT resection and suggests a possible relationship between subcortical stroke and N2 latency changes that warrants further study. https://thejns.org/doi/10.3171/CASE25915
Depth electrode implantation is widely used in the presurgical evaluation of drug-resistant epilepsy. Conventional orthogonal temporal trajectories are commonly used to access mesial temporal structures; however, these approaches may be technically challenging in patients with prior cranial surgery or dural reconstruction.
A 53-year-old woman developed epilepsy following herpes encephalitis at 29 years of age. She previously underwent right frontal lobectomy with artificial dural reconstruction but continued to experience medically refractory seizures. Presurgical evaluation suggested a complex epileptogenic network involving bilateral mesial temporal structures and additional cortical regions. Because a large artificial dural graft and postoperative skull defects limited conventional temporal entry points, all electrodes were implanted using posterior occipitotemporal trajectories. Stereoelectroencephalography (SEEG) monitoring recorded 19 seizures arising from the right hippocampus, right parietal cortex, and left hippocampus. Although multiple seizure onset regions were identified, the right hippocampus was considered the principal surgical target based on seizure frequency and propagation patterns. The patient subsequently underwent right anterior temporal lobectomy with amygdalohippocampectomy and achieved an Engel class II seizure outcome at 6-month follow-up.
Posterior occipitotemporal trajectories represent a practical alternative for SEEG implantation when conventional approaches are limited by prior cranial reconstruction.
Simple Summary Adult brainstem gliomas are rare tumors located in one of the most functionally critical regions of the central nervous system. Surgical treatment carries a substantial risk of neurological injury, making intraoperative neurophysiological monitoring (IONM) an important tool for preserving neural function. In this retrospective study, we evaluated the association between intraoperative electrophysiological changes and early postoperative neurological outcomes in 22 adults who underwent surgical resection of brainstem gliomas. Somatosensory and motor evoked potential changes were frequently observed during surgery; however, conventional amplitude-based warning criteria were not associated with neurological status at hospital discharge. In contrast, increases in motor stimulation thresholds were significantly associated with postoperative complications. These findings suggest that dynamic changes in motor threshold may provide clinically relevant information beyond traditional amplitude-based monitoring parameters. Larger prospective studies are needed to confirm the prognostic value of specific IONM metrics and to optimize intraoperative monitoring strategies during brainstem glioma surgery.
G. Pauletto, B. Skrap, B. Tomasino et al.· Current Oncology· 0 citations
Background: Gliomas of the medial frontal lobe extending into the gyrus cinguli represent a challenging neurosurgical entity because of their deep location, complex vascular anatomy, and proximity to functionally significant cortical and subcortical structures. Awake craniotomy with functional mapping, diffusion tensor imaging (DTI)-based planning, neuronavigation, and cortical/subcortical stimulation represents an important contemporary strategy for maximal safe glioma resection, particularly for tumors located within or near eloquent networks. However, in carefully selected cases, standard microsurgical craniotomy under general anesthesia may remain a valuable option when detailed anatomical and venous assessment identifies a safe operative corridor. Dense frontal bridging veins draining into the superior sagittal sinus may limit standard interhemispheric approaches and influence the selection of an alternative transcortical route. Case Description: We report the case of a 31-year-old right-handed woman presenting with progressive headache, seizures, and urinary incontinence. Preoperative magnetic resonance imaging revealed a large intra-axial tumor of the right medial frontal lobe with extension toward the anterior cingulate gyrus and partial involvement of the corpus callosum. Neuropsychological assessment demonstrated moderate frontal–subcortical cognitive impairment. Preoperative venous imaging identified multiple frontal bridging veins draining into the superior sagittal sinus, which made the interhemispheric surgical corridor potentially unsafe. A tailored transcortical approach through the superior frontal gyrus was therefore selected. The procedure was performed under general anesthesia without awake mapping, DTI-based tractography, neuronavigation, or intraoperative cortical/subcortical stimulation. Tumor resection was performed using a three-trajectory strategy with early identification of the pericallosal–callosomarginal arterial complex according to the vessel-first principle, while minimizing brain retraction and preserving bridging veins. The component of the tumor tightly adherent to the cingulate cortex was intentionally left to preserve functionally significant structures. Near-total resection was achieved without new permanent neurological deficits, and postoperative neuropsychological changes were transient with subsequent recovery. Conclusion: This case does not propose an alternative to awake mapping or modern functional adjuncts in glioma surgery. Rather, it illustrates that standard microsurgical craniotomy under general anesthesia may retain clinical value in carefully selected medial frontal gliomas involving the cingulate gyrus, particularly when bridging venous anatomy makes an interhemispheric corridor potentially unsafe. Careful anatomical planning, preservation of bridging veins, early arterial identification, minimization of brain retraction, and function-oriented resection may allow safe tumor removal in selected cases.
Jakhongirmirzo Z. Yoldoshev, Uygun Altibayev, G. Kariev et al.· Surgical neurology internati...· 0 citations
OBJECTIVE
Resections of the supplementary motor area (SMA) in the dorsomedial frontal cortex (DMFC) have traditionally been thought to result in predictable postoperative motor deficits termed the "SMA syndrome." However, the true incidence, etiology, and duration of these deficits seem overstated in the modern era. Herein, the authors aimed to critically evaluate and reassess the SMA syndrome in the context of surgical navigation, retractorless surgery, and contemporary motor mapping and monitoring techniques.
METHODS
The authors retrospectively reviewed the electronic medical records of all patients who underwent DMFC resections for tumors or epilepsy between 2004 and 2025 at a single institution. Patients with insufficient data were excluded from the study. Compiled data included demographics, presenting symptoms, surgical characteristics, intraoperative mapping, postoperative motor function, postoperative complications, and follow-up visits up to 12 weeks.
RESULTS
Eighty patients were eligible for study inclusion. New postoperative motor deficits occurred in 33.8% of patients (27/80); however, when cases with concomitant involvement of the primary motor cortex or cingulate gyrus were excluded, the incidence of SMA-specific deficits was only 10.0% (8/80). Moreover, 81.5% of new deficits (22/27) resolved by a median of 13 days, and 51.9% (14/27) recovered very rapidly. Patients with new deficits were more likely to have right hemisphere resections (p = 0.033). Motor strip involvement (p = 0.019) and postoperative complications (p = 0.042) were also associated with new deficits. No association was found with the use of intraoperative mapping, percentage of resected SMA, or other clinical characteristics. As expected, patients with new deficits experienced a longer postoperative hospital course (p = 0.023) and were more often discharged to inpatient rehabilitation (p = 0.012). Permanent deficits occurred in 6.3% of patients (5/80) and were more often associated with preoperative weakness (p = 0.047) and a major postoperative complication (p = 0.013).
CONCLUSIONS
These findings challenge the classic perspectives on SMA syndrome. When resections are confined to the SMA, postoperative deficits are uncommon, mild, and resolved rapidly. Persistent deficits reflect injury to adjacent eloquent regions rather than injury from the SMA resection itself. With gravity-based retraction, modern navigation, and functional mapping, DMFC lesions can be resected more safely than in the past. Study findings support redefining SMA syndrome and expanding the role of mapping-guided resections in this region.
A. Dono, Shalin Shah, Maria Morkas et al.· Journal of Neurosurgery· 0 citations
Objective Deep brain stimulation of the anterior nucleus of the thalamus (ANT-DBS) is an established palliative therapy for drug-resistant focal epilepsy; however, its efficacy for epileptic spasms (ES) and the clinical utility of unilateral stimulation remain unclear. To address these issues, we report a case of drug-resistant focal epilepsy with ES treated with unilateral ANT-DBS. Case An 18-year-old right-handed male with focal cortical dysplasia type I had long-standing drug-resistant epilepsy. Despite multiple resective and palliative surgeries—including right frontal disconnection, corpus callosotomy, right anterior temporal lobectomy, and vagus nerve stimulation—daily ES, weekly focal impaired consciousness seizures (FIC), and monthly focal-to-bilateral tonic-clonic seizures (FBTC) persisted. Presurgical evaluation suggested an epileptic focus in the left temporal lobe for FIC/FBTC. ANT-DBS was planned for seizure alleviation. Lead implantation on the right side was considered unfavorable because of marked postsurgical atrophy. Therefore, unilateral ANT-DBS lead implantation on the left side was performed. Results After implantation, ES frequency transiently decreased (median 0.46 seizures/day) but later increased during follow-up. Stimulation was initiated on postoperative day 22. After the stimulation amplitude reached ≥2.0 mA (postoperative day 92), the median spasm frequency decreased again to 0.31/day, lower than the preoperative baseline of 0.75/day (58.1% reduction; p = 0.012). FIC frequency also decreased from 0.21/day to 0.09/day (60.0% reduction; p = 0.121). Significance Unilateral ANT-DBS was associated with a clinically meaningful reduction in ES in this highly refractory case, suggesting a potential therapeutic role even when bilateral implantation is not feasible.
Takumi Mitsuhashi, Y. Iimura, Hiroharu Suzuki et al.· Epilepsy & Behavior Reports· 0 citations
BACKGROUND Intraoperative somatosensory evoked potentials (SSEPs) are routinely used during spine surgery to assess the integrity of white matter pathways and identify potential neurological injury. Their use as a bedside diagnostic adjunct for unexplained postoperative neurological deficits, particularly when functional neurological disorder (FND) is suspected, has not been well described. OBSERVATIONS A 53-year-old woman developed profound lower extremity weakness and sensory loss after L3–5 decompression and fusion despite stable intraoperative neuromonitoring and imaging findings that did not explain her deficits. Bedside SSEPs remained normal and comparable to intraoperative recordings. Subsequent revision surgery also demonstrated stable SSEPs and robust transcranial motor evoked potentials. Together with inconsistent examination findings and preserved movement when distracted, these results supported a multidisciplinary diagnosis of FND. LESSONS Bedside SSEPs may provide objective evidence of preserved sensory pathway function in patients with unexplained postoperative neurological deficits and may assist in distinguishing functional symptoms from structural injury. https://thejns.org/doi/10.3171/CASE251006
BS Sirisha Nouduri, Mbbs Ayesha Akbar Waheed, Hallie Triplett et al.· Journal of Neurosurgery: Cas...· 0 citations
