Seizures in cerebral arteriovenous malformations: type, clinical course, and medical management

We investigated the type and early clinical course of seizure disorders in cerebral arteriovenous malformations (AVMs). Decisions on invasive treatment for AVMs depend on detailed knowledge of the natural course and prognosis of neurologic sequelae. Among 328 patients of a prospective cerebral AVM databank 92 (28%) presented with seizures unrelated to haemorrhage. Under a median observation time of 2.2 years (mean 3.8 years) the 92 patients received 454 follow-up examinations (median time interval 4.6 months). All patients were treated with anticonvulsant medication. During the observation period sixty (65%) patients received staged endovascular glue embolisation. The effect of staged embolisation on seizure recurrence was tested univariately by comparing patients undergoing embolisation versus those without endovascular treatment. At the time of enrolment in the database, elementary (motor or sensory) and partial complex seizures were described in twenty (22 %) and one (1%) patients, respectively. Generalized seizures without focal initiation were reported in sixty (65%) and with focal initiation in 11 (12%) patients. 57 (62%) cases had suffered a seizure as a first single event, ten (11%) had weekly, 17 (19%) monthly, and eight (9%) patients had seizures once per year. In the following clinical course, complete cessation of seizure activity was seen in 69 (75%). Ten (11%) patients continued to have seizures at a rate of once per year or less. 13 (14%) cases continued to have weekly to monthly events with only four (4%) of them showing (monthly) grand mal. An early beneficial effect of staged embolisation on seizure recurrence was not observed. Seizure disorders in cerebral AVMs show a benign early course, leaving few patients with insufficient seizure control. The differential longterm effect of invasive AVM treatment on seizure control should be subject to clinical trials.