國井 尚人

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.

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: 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.

Immature teratomas of the pineal region are a subtype of non-germinomatous germ cell tumors typically associated with early recurrence. Ultra-late recurrence decades after initial treatment is exceedingly uncommon. We report an immature teratoma case in the pineal region that recurred 35 years after subtotal resection and chemoradiotherapy, showing somatic-type malignant transformation into adenoid cystic carcinoma-like adenocarcinoma. A 16-year-old boy initially underwent ventriculoperitoneal shunting followed by tumor resection, after the pathological confirmation of an immature teratoma (grade 2 according to the ovarian teratoma grading system). A small residual lesion remained, and the patient's condition remained stable for more than a decade, but he was lost to follow-up. At 51 years of age, the patient presented with obstructive hydrocephalus and tumor regrowth. Preoperative serum and cerebrospinal fluid tumor markers levels were normal. An endoscopic biopsy revealed poorly differentiated adenocarcinoma. Resection through an occipital transtentorial approach indicated tumor infiltration into the bilateral thalamus. Histology showed glandular and cartilaginous components with marked atypia and immunohistochemical features resembling adenoid cystic carcinoma, whereas germ cell markers were negative, thus establishing a diagnosis of teratoma with somatic-type malignant transformation. Despite ifosfamide, carboplatin, and etoposide chemotherapy (all at 50% dose) and stereotactic radiosurgery, the disease progressed with leptomeningeal dissemination, and the patient died 613 days after he underwent the second surgery. This case represents the longest reported interval of recurrence for a central nervous system immature teratoma and highlights the possibility of long-term tumor dormancy followed by malignant transformation. Lifelong surveillance is therefore warranted in patients with residual immature teratomas.

BACKGROUND: Hair shaving during craniotomy is traditionally performed to facilitate skin preparation and improve intraoperative visibility, but it may cause cosmetic and psychological concerns for patients. Evidence supporting its role in reducing postoperative infections is limited. In this study, we evaluated patient satisfaction with a shave-free craniotomy technique and examined postoperative infection rates. METHODS: We retrospectively reviewed patients who underwent shave-free craniotomy performed by the author between April 2018 and April 2023. Procedures that did not require shaving, as well as surgeries in which additional or extended incisions were anticipated, were excluded. Eligible patients were mailed a questionnaire between July and October 2023. The survey assessed (1) preoperative anxiety related to shaving, (2) expectations regarding shaving before preoperative explanations, and (3) satisfaction with the shave-free procedure (0-100 scale). Postoperative wound infections were also assessed. RESULTS: A total of 116 surgeries were performed on 115 patients. Fifty-five patients (48%) responded to the questionnaire. Shaving-related anxiety accounted for 10.7% of overall preoperative anxiety. Before receiving preoperative explanations, 18% of patients expected total shaving, 80% expected partial shaving, and 1.8% expected no shaving. Satisfaction scores were high for both women (95.8 ± 16.9) and men (96.7 ± 5.7). Two postoperative wound infections (1.7%) were observed, one of which required bone flap removal. CONCLUSION: Shave-free craniotomies were associated with high patient satisfaction and did not increase the risk of postoperative infections. Although cosmetic concerns differ among individuals, avoiding hair removal may help reduce anxiety in some patients without compromising surgical safety.