小嶋 大二朗

Abstract The lateralized efficacy of vagus nerve stimulation (VNS) remains insufficiently explored. We report a case of drug-resistant epilepsy with bilateral frontal lobe seizure onset, treated with left cervical VNS. Preoperative video- electroencephalogram revealed predominant interictal discharges in the right hemisphere and frequent seizures from both hemispheres. Following VNS, overall seizure frequency decreased. Notably, stereo-electroencephalography performed 15 months postoperatively showed a marked reduction in right-sided seizures, while left-sided seizures remained frequent. This case highlights the potential lateralized effect of VNS in a single patient with bilateral frontal lobe epilepsy, suggesting that VNS may preferentially suppress seizures originating from the right hemisphere.

BACKGROUND: Diploic veins may act as collateral venous pathways in cases of meningioma with venous sinus invasion. Diploic vein blood flow should be preoperatively evaluated to consider preserving the veins. In this study, we evaluated the use of time-resolved whole-head computed tomography angiography (4D-CTA)-which is less patient-intensive than digital subtraction angiography (DSA)-for assessing diploic vein blood flow and the positional relationship between typical craniotomy approaches and diploic veins. METHODS: We retrospectively examined 231 patients who underwent surgery for intracranial meningioma. We performed contrast-enhanced magnetic resonance imaging (MRI) to evaluate diploic vein pathways and compared the visualization rates of diploic vein blood flow assessed using 4D-CTA and DSA. Subsequently, we evaluated the rates of the diploic veins transected during craniotomy by comparing the pre- and postoperative contrast-enhanced MRI. RESULTS: The diagnostic performance of 4D-CTA was assessed in 45 patients. Of the 320 diploic veins identified in these patients, blood flow in 70 (21.9%) diploic veins was identified by 4D-CTA and DSA, and both results were consistent. To assess the transection rates of the diploic veins, 150 patients were included. A trend towards a high transection rate of the diploic vein in the basal interhemispheric, frontotemporal, orbitozygomatic, combined transpetrosal, and convexity craniotomy approaches was observed. CONCLUSIONS: In patients with meningiomas, both 4D-CTA and DSA are useful in evaluating diploic vein blood flow. In meningiomas with venous sinus invasion, determining the extent of craniotomy after understanding the pathways and blood flow of diploic veins is recommended.