Efficacy of vagus nerve stimulation for drug-resistant epilepsy in a survivor of poor-grade subarachnoid hemorrhage: A case report

A man in his 60s had undergone clipping for a subarachnoid hemorrhage (SAH) due to a ruptured anterior communicating artery aneurysm in his 40s. He survived cerebral vasospasms following surgery for poor-grade SAH and required anti-seizure medications (ASMs) for post-stroke epilepsy. More than 20 years after the clipping, he developed focal impaired awareness seizure, which decreased his quality of life (QOL). Computed tomography (CT) showed an infarct in the left frontal lobe. 123I-iomazenil single-photon emission CT showed decreased benzodiazepine accumulation in the left frontal and medial temporal lobes. An interictal electroencephalogram showed epileptic discharges in the left temporal region. We diagnosed focal epilepsy and adjusted ASMs based on seizure control. However, the seizures were not controlled, and the adverse effects worsened with dosage increase. The condition was diagnosed as drug-resistant epilepsy, and the patient underwent vagus nerve stimulation. Postoperatively, we confirmed control of seizures and improvement of QOL.