Abstracts

Rationale: To study the effect of multiple subpial transection (MST) on cortical excitability in patients with intractable infantile spasms and hypsarrhythmia. Methods: Three patients received MSTs. Presurgical MRI, PET, and long-term video-EEG were used to identify and localize coexisting partial seizures. Epileptogenic gyri were transected with reference to intraoperative electrocorticography (ECoG). Surgical outcome and related neurophysiological changes were assessed using postoperative long-term scalp EEG, seizure/spasm numbers, and PET scans.Results: Intraoperative ECoG disclosed the immediate effect of MSTs with disruption of synchronous cortical EEG activities on the targeted cortices. Clinically, the reduction of seizure/spasm frequency and developmental improvement were obtained and maintained continuously. The hypsarrhythmic EEG revealed less randomization and better organization. The glucose metabolism in the surgical regions increased.Conclusions: The good outcome suggests the validity of MST in the treatment of uncontrolled infantile spasms and sustains the rule of focal cortical excitation in spasm seizures.