Epilepsy surgery in bifrontal injury from prior craniopharyngioma resections.

Abstract

Epilepsy surgery in frontal lobe epilepsy (FLE) has less favorable seizure-free outcomes than temporal lobe epilepsies. Possible contributing factors include fast propagation patterns and large clinically silent areas which are characteristics of the frontal lobes. Bilateral frontal lobe abnormalities on MRI are another relative contraindication to epilepsy surgery. For example, bilateral encephalomalacia may be a presupposition to bilateral or multifocal epilepsy. The possibility of potential disinhibition with already poor reserves may be another deterrent to consideration for resective epilepsy surgery. As such, conventional surgical approaches to intractable epilepsy with bilateral frontal injury may be limited to palliative procedures like vagus nerve stimulation and corpus callosotomy. We present a case in which the epileptogenic zone was a subset of the acquired, bilateral, cystic encephalomalacia. This iatrogenic injury resulted from two prior craniotomies for excision of craniopharyngioma and its recurrence.Following the initial bilateral and subsequent unilateral, subdural grid- and depth electrode-based localization and resection, our patient has remained seizure-free 2 years after epilepsy surgery with marked improvement in her quality of life, as corroborated by her neuropsychological test scores. Our patient's clinical course is testament to the potential role for resective strategies in selected cases of intractable epilepsy associated with bifrontal injury. Reversal of behavioral deficits with frontal lobe epilepsy surgery such as in this patient provides a unique opportunity to further our understanding of the complex nature of frontal lobe function.