[Characteristics of epileptic seizures associated with cerebral arteriovenous malformations].

PURPOSES

The purpose of this study is to analyze the characteristics of epileptic seizures associated with cerebral arteriovenous malformations treated by radiosurgery.

PATIENTS AND METHODS

Seven hundred and two patients are studied (406 men, 296 women) with a mean age of 33 when radiosurgery was performed. 210 patients had epileptic seizures; those seizures either uniquely revealed the arteriovenous malformation or were associated with other clinical signs. Seizures occurring after an hemorrhage were excluded from the study. We studied the age category upon seizures occurrence, the malformation localization, type of seizure (partial, generalized, or partial secondary generalized), the history related to the epileptic seizures, the clinical topographical correlation, the number of seizures, their duration prior to the radiosurgery, antiepileptic treatment provided, electroence-phalographic characteristics, angiographic characteristics, prior endovascular or surgical treatment, and factors associated with severe seizure.

RESULTS

Epileptic seizures revealed the arteriovenous malformations in 30% of the cases; they predominated between 10 and 40 years (80.5%) with a peak between 20 and 30 years. The malformation localization most frequently associated with seizures were temporal and rolandic for partial seizures, whereas frontal or sylvian localization were predominantly associated with generalized seizures. The type of seizure was, in all cases, related to the malformation localization because of the initial signs seizure. 47.6% of the patients showed a limited number of seizures (between 2 and 20), 27.6% showed only a single seizure, and 24.7% suffered from severe epilepsy. Generalized seizures are unique in the majority of cases (61.8%) whereas partial seizures were severe in 47.6% of the cases. The majority of patients are under a single-drug therapy (79%). The EEG patterns showed a small increase of slow and sharp localized waves in patients presenting seizures compared with the global population (27% and 15% respectively). Severe seizures predominated between 10 and 19 years of age; seizures were exclusively partial in 59.6% of the cases and secondary generalized in 40.4%, their frequencies were between 1 to 4 per month in the majority of cases (59.1%), the delay was often more than 10 years (57.7%), status epilepticus was rare (5.8%), temporal and rolandic localization were predominant, social and professional insertion of the patient was preserved in 87.5% of the cases, and seizures did not provoke any death. The angiographic characteristics associated with seizures were: superficial localization, volume, superficial venous drainage, recruitment and venous divergence.

CONCLUSION

Anatomic and topographic characteristics of cerebral arterio-venous malformations may provide information on the features of seizures associated with them.