Surgical Outcome in Patients with Epilepsy with Occult Vascular Malformations Treated with Lesionectomy

Abstract

Summary:Purpose: This retrospective study reports the longterm surgical outcome of patients with medically refractory epilepsy and vascular malformations who were treated with lesionectomy. A detailed analysis of surgical failures had been performed in an attempt to define predictors of surgical success and failure.Methods: Fifteen patients with medically intractable epilepsy and angiographically occult vascular malformations (AOVMs) were treated surgically with lesionectomy at Duke University Medical Center. Lesionectomy consisted of removal of the AOVM and surrounding hemosiderin-stained brain only, without the use of electrocorticography (ECoG) to guide resection.Results: Eleven (73%) patients are seizure free after lesionectomy. Three showed no significant improvement, and one patient died, presumably after a seizure. Age of onset, duration of seizures, age at resection, and gender did not affect outcome. All patients with neocortical AOVMs in whom EEG findings correlated with the site of the lesion were seizure free after lesional resection. Treatment failures were associated with the presence of multiple intracranial lesions, poorly localized or diffuse EEG findings, discordant positron emission tomography (PET) imaging, or with a lesion in close proximity to the limbic system.Conclusions: Lesionectomy, with removal of surrounding hemosiderin-stained brain, can be considered the procedure of choice in carefully selected patients with epilepsy with occult vascular malformations.

Long-Term Seizure Control After Resection of Supratentorial Cavernomas

“…In a study of 15 patients with occult vascular malformations, Kraemer et al (21) concluded that the removal of the lesion and adjacent hemosiderin was highly effective in treating seizures, as 73.3% of patients were seizure-free postoperatively. The same authors proved experimentally, in other studies, that the gliotic, hemosiderin-laden tissue of vascular malformations was associated with epileptogenic activity (19,20).…”

Prognostic factors for post-operative seizure outcomes after cavernous malformation treatment

“…1,6,7,10,[25][26][27][28][29][30][31][32][33][34][35][36][37][38] Cavernous malformations may not directly generate seizures, 4,39 but it is hypothesized that the area surrounding the malformation, the ''hemosiderin rim'', is the epileptogenic region due to iron deposition from recurrent hemorrhage. 4,[39][40][41] Hence, removing this hemosiderin rim during cavernous malformation surgical resection has been postulated to improve seizure outcomes.…”

When drugs don’t work

“…Specifically, postoperative seizure outcome for these cases is almost as good as that of temporal lobectomies. 21,[31][32][33] This is true for various lesions, and excellent outcomes (seizure-free or almost seizure-free) have been reported in 73 to 83% of cases for vascular malformations, [34][35][36] in 70% of cases for encephalomalacia, 37 and in 63 to 79% of cases for neoplasms. 38,39 Numbers are somewhat lower for cortical dysplasias, ranging from 35 to 42%.…”