Surgical management and long-term seizure outcome after epilepsy surgery for different types of epilepsy associated with cerebral cavernous malformations

Purpose: Precise outcome data about the surgical therapy of cerebral cavernous malformation (CCM)-associated epilepsy is scarce regarding different epilepsy types, surgical approach, and outcome. Long-term outcome in patients with CCM-associated epilepsy is analyzed in a large single-center series.

Methods: Seizure outcome data >24 months was available in 118 patients. The influence of different parameters of preoperative workup and surgical technique was analyzed with regard to seizure outcome.

Key findings: The study cohort comprised 76 patients with drug-resistant epilepsy (DRE), 20 patients with chronic epilepsy that did not meet the definition of DRE, as well as 22 patients with sporadic seizures. Temporal localization of CCMs predisposed to develop DRE. Detailed epileptologic workup was performed in 85 patients; invasive monitoring was done in 23 (37%) of 76 DRE cases. In 84% of DRE cases more extensive resections were performed. Mean follow-up varied between 107 and 137 months for the three groups. Seizure freedom in DRE was 88%, in chronic epilepsy 80%, and in sporadic seizures was 91%. Longer symptom duration was associated with worse seizure outcome. Outcome of patients who underwent invasive monitoring was not worse. The outcome in CCM-associated DRE can be good if more extensive resections are used and if noninvasive and/or invasive presurgical epileptologic workup is used whenever indicated. DRE was considerably more frequent in the temporal lobe, suggesting that temporal localization predisposes development of DRE. Seizure freedom rates were stable over a long period.

Significance: Surgical therapy of CCM-associated seizures and epilepsy can be successful if different surgical techniques according to presurgical evaluation are realized. To prevent clinical worsening into DRE, surgical intervention in CCM-associated epilepsy may be considered early.