Surgical treatment of independent bitemporal lobe epilepsy defined by invasive recordings

Abstract

Objectives: Bitemporal lobe epilepsy is commonly encountered in the evaluation of pharmacoresistant epilepsy. Yet the role of surgery in the management of these patients is unclear. This study evaluates the impact of surgery on seizure tendency and quality of life, as well as prognostic indicators in individuals with proven ictal onset bitemporal lobe epilepsy.

Methods: The study population comprised all patients who underwent temporal lobe surgery over a 10 year period and had ictal onset bitemporal lobe epilepsy identified with intracranial electrode monitoring. Patients with extratemporal seizure generators were excluded. Subjects were divided into a favourable or less favourable group based on the results of surgery on seizure tendency.

Results: 11 subjects were studied with a mean 5.9 years of post-surgical follow-up. Six subjects constituted the favourable outcome group. Four had a less favourable outcome and continued to have frequent seizures after surgery; however, three with less favourable seizure reduction subjectively reported improvement in quality of life after surgery as a result of reduced seizure frequency and severity, and reduced medications. No single preoperative factor was significantly different between the groups, including ictal EEG laterality, epilepsy duration, age at surgery, age at seizure onset and mesial temporal atrophy.

Conclusions: Surgical resection is an important treatment option for medically intractable bitemporal epilepsy. The proportion of seizures arising from one temporal lobe is not reliable as a single indicator to prognosticate the results of surgery on seizure tendency. In addition, individuals who achieved only palliation by reducing seizure frequency experienced improvement in quality of life.