井林 賢志

BACKGROUND: Temporal encephaloceles (TEs) are increasingly recognized as epileptogenic lesions in drug-resistant temporal lobe epilepsy. However, endoscopic endonasal surgery performed primarily to resect epileptogenic lesions remains extremely rare, largely because defining the optimal extent of resection is challenging without direct electrophysiological confirmation. OBSERVATIONS: A 41-year-old right-handed man presented with drug-resistant focal impaired consciousness seizures. MRI revealed a right TE herniating into the lateral recess of the sphenoid sinus. Scalp EEG suggested seizure onset in the right anterior temporal region with no evidence of a widespread temporal epileptogenic network. Through an endoscopic endonasal transpterygoid approach, the encephalocele and adjacent temporal dura mater were exposed. Depth electrodes placed into the encephalocele and adjacent cortex demonstrated frequent spikes in both sites, confirming epileptogenicity. The encephalocele and a 7-mm margin of adjacent cortex were resected, followed by multilayer skull base reconstruction. The patient experienced no complications and remained seizure free for 48 months. LESSONS: Endonasal depth EEG enables direct confirmation of epileptogenicity in encephalocele-associated epilepsy and supports minimally invasive, tailored lesionectomy. In appropriately selected patients, particularly those without evidence of a widespread mesial temporal epileptogenic network, use of an endoscopic endonasal approach may avoid craniotomy while achieving durable seizure freedom. https://thejns.org/doi/10.3171/CASE25965.

BACKGROUND: The incidence of cerebral aneurysms in polyarteritis nodosa (PN) is low, and reports of subarachnoid hemorrhage (SAH) in patients with PN are even rarer. The necessity of head imaging may be underestimated, particularly when the patient is in remission. OBSERVATIONS: A 20-year-old female with PN, who had been in remission following anti-interleukin-6 receptor antibody therapy, developed SAH and was admitted to the authors' department. Cerebral angiography revealed multiple beaded changes in both carotid and vertebral arterial systems, along with several small aneurysms. These findings posed substantial difficulty in identifying the bleeding source and proceeding with surgical intervention. Therefore, the authors intensified the immunosuppressive therapy targeting the underlying PN. The patient remained free from rebleeding, her headaches and other symptoms resolved, and she was discharged in ambulatory condition. Follow-up MR angiography 3 months after discharge confirmed resolution of the small aneurysms. LESSONS: This case suggests that enhanced immunosuppressive therapy may be effective in treating both extracranial and intracranial vascular lesions in PN. In patients with PN, early and serial head imaging may be beneficial. The appearance of de novo aneurysms in the context of disease progression may indicate the need for more aggressive treatment. https://thejns.org/doi/10.3171/CASE25617.

OBJECTIVE: Patients with temporal lobe epilepsy (TLE) suffer from epileptic seizures and memory decline. While focal resection eliminates seizures in 60-70% of patients, surgery carries the risk of further compromising memory. We hypothesized that hippocampal neurofeedback (NF) will induce targeted brain activity associated with memory function. METHODS: Patients with intracranial electrodes implanted in bilateral hippocampi performed a memory NF task, developed specifically for this project. The NF task involved real-time analysis of hippocampal activity using the electrode in the less-affected hippocampus while conducting a memory task. Changes in theta activity and task performance were assessed. RESULTS: The NF task was conducted in seven TLE patients. In five patients, theta activity increased significantly in the targeted hippocampus (Mann-Kendall test; p < 0.05). Mixed linear model analysis across all sessions revealed a significant increase in theta activity in the targeted hippocampus (p = 0.0032), with no significant change contralaterally (p = 0.19). Three additional TLE patients underwent random NF to assess if theta activity was induced merely by the encoding process, but none of them showed significant changes in theta activity. CONCLUSION: Memory NF task effectively induced targeted hippocampal activity in TLE patients. SIGNIFICANCE: Hippocampal NF may enhance memory function in TLE patients prior to focal resection.

BACKGROUND: Redo awake surgery is ideal for recurrent malignant gliomas in the language-dominant hemisphere, but it may not always be optimal because of inadequate awake mapping. In this report, the authors describe a case of recurrent language-dominant frontal glioma in which a super-selective Wada (ssWada) test and super-selective cone-beam CT angiography (ssCBCTA) enabled successful tumor removal under general anesthesia after awake surgery. OBSERVATIONS: A woman in her 30s underwent awake surgery for left frontal glioma recurrence 2 years after the initial resection. Three years after another recurrence, the ssWada test and ssCBCTA revealed that the tumor-supplying artery did not perfuse the functional cortex, allowing safe and maximal resection under general anesthesia. Postoperatively, she had mild motor aphasia but recovered quickly with minimal sequelae. LESSONS: The combined use of the ssWada test and ssCBCTA enables precise preoperative language mapping and safe tumor resection. Originally developed for epilepsy surgery, the ssWada test is valuable for functional mapping and, when paired with ssCBCTA, provides a 3D understanding of the lesions. This combination serves as a critical preoperative tool for tumors in the language-dominant hemisphere. https://thejns.org/doi/10.3171/CASE25384.