Abstracts

Rationale: Cavernous malformation (CM) is a disorder of small arteries and veins in brain, which often presents with headaches and seizures. Although surgical treatment of CM is primarily to remove mass effect and to prevent further intracerebral hemorrhages, seizure control is another important goal of the CM surgery. In fact, some patients may undergo surgery mainly to control their refractory seizures even when the size of CM is small. Seizure outcome after surgery could be depend on multiple factors such as the lesion location (temporal vs. extratemporal lobe), size of CM and the extent of surgical resection. However, it is not clear whether the timing of the surgery (early vs. late) for CM plays a role in seizure outcome. We conducted a study to evaluate whether early surgical intervention improves the seizure outcome in patients with CM and refractory seizures. Methods: We retrospectively reviewed patients who underwent lesionectomy of supratentorial CM at the Barrow Neurological Institute. To examine the effectiveness of cortical/subcortical lesionectomy with respect to seizure control, patients with thalamic, midbrain, pontine, medullary, or cerebellar CM were excluded. We then further identified patients with recurrent seizures despite medical therapy, and divided them into two groups depending on the timing of the surgery: Group 1 (surgery within 6 month of seizure onset) and Group 2 (surgery after 6 month of seizure onset). The patients were followed at least 6 months after the surgery and the seizure outcome was categorized according to Engel’s class. The protocol and data collection were approved by the local Institutional Review Boards. Results: There were 118 patients who underwent resection for supratentorial CM. Among them, 67 had recurrent seizures before surgery. All patients underwent simple lesionectomy without extralesional cortical resection or ECoG guided resection. Of these 67 patients, 48 patients had at least 6 months of clinical follow-up (median, 30 months). Fifteen patients were identified as Group 1 and 33 as Group 2. All 15 (100%) of the Group 1 patients became seizure free after the surgery (Engel’s class I), and most of these patients (93%) discontinued their anticonvulsant medications. Of the 33 patients in Group 2, 18 (55%) had class I, 7 (21%) had grade II, and 8 (24%) had class III or worse outcomes. Conclusions: Seizures are the common presenting symptoms of CM. These patients may develop refractory seizures and surgical intervention could be quite effective. Although the small sample size for this study limits definitive conclusion, our study suggests that early surgical treatment of CM provides better seizure outcome.