Angiographic characteristics of epileptogenic arteriovenous malformations and effectiveness in the seizure control after treatment with radiosurgery.

OBJETIVE

Define the angiographic characteristics of epileptogenic arteriovenous malformations (AVM) and assess symptom control of the seizure after treatment with radiosurgery.

MATERIAL AND METHODS

Between 1996 and 2006, a total of 237 adults patients were diagnosed with AVM and were treated in our center by radiosurgery with linear accelerator. We analyzed demographics, clinicals, angiographics and radiosurgicals characteristics and the complications of the procedure in each of them. The first symptom was a seizure in 68 of them and the subsequent analysis of the treatment effectiveness for the seizure control was done, and the possible predictive factors of AVM nidus evolution were assessed.

RESULT

The average volume of the epileptogenic AVMs was 7.17 cc, compared ot the non-epileptogenic AVM 5.06 cc (p<0.03). Other differentiating factors were surface blood supply (p<0.003), venous ectasia (p<0.064), angiogenesis (p<0.078), and the presence of unrelated aneurysms (p<0.08). For 68 patients (28.7%) with seizures a clinical control (Seizure Frequency Scoring System SFSS ≤2) was obtained in 70% of patients and there was an excellent control (SFSS ≤1) in 25% of them. The percent occlusion of their AVMs was 50%. There was statistical significance with SFSS ≤1 (p<0.01), but was not any significance with SFSS ≤2. Age (p<0.003) and diffuse nidus morphology (p<0.05) were predictors of good AVM nidus evolution.

CONCLUSIONS

The stereotactic radiosurgery seems to be an effective method for control of symptomatic seizures for intracranial AVMs. Certain angiographic characteristics, such as the volume, surface blood supply, angiogenesis, venous ectasia, and unrelated aneurysms to the AVMs, seem to influence the appearance of epileptic seizures.