Seizure outcomes after stereotactic radiosurgery for cerebral arteriovenous malformations

To determine the effect of stereotactic radiosurgery on seizure outcomes for patients with intracerebral arteriovenous malformations (AVM).

Between May 1990 and December 1998, 65 patients with a history of single or recurrent seizures underwent AVM radiosurgery, had more than 1 year of follow-up, and sufficient data to record an Engel seizure frequency score. The authors reviewed their records and updated clinical information when necessary with direct patient contact. Follow-up ranged from 12 to 144 months (median, 48 months). Seizure frequency was compared before and after radiosurgery with the Engel Seizure Frequency Scoring System.

Overall, 26 patients (51%) were seizure-free (aura-free) after radiosurgery at 3-year follow-up; 40 patients (78%) had an excellent outcome (non-disabling simple partial seizures only) at 3-year follow-up. Factors associated with seizure-free or excellent outcomes include a low seizure frequency score (<4) before radiosurgery and smaller size and diameter AVM. Twenty-three patients had intractable partial epilepsy prior to treatment. Twelve (52%) of 23 and 11 of 18 (61%) patients with medically intractable partial epilepsy had excellent outcomes at years 1 and 3.

Overall, stereotactic radiosurgery improves seizure outcomes in the majority of patients and more than half of the patients with medically intractable partial epilepsy had an excellent seizure outcome after radiosurgery.