Earlier Surgery in Medically Refractory Frontal Lobe Epilepsy Is Associated With Better Outcomes

S. Andrew Josephson, M.D.


AccessMedicine from McGraw-Hill 

Frontal lobe epilepsy can be treated with medical or surgical approaches. In general, surgical outcomes have been better in the more common temporal lobe epilepsy compared with frontal lobe epilepsy for somewhat unclear reasons. While the typical approach in frontal lobe epilepsy is to trial a number of medications prior to declaring the patient medically refractory and referring to a surgical center, earlier surgery may indeed lead to better long-term outcomes as has been shown in temporal lobe epilepsy. Simasathien and colleagues (2013) examined this question in a large cohort of frontal lobe epilepsy patients.

The authors retrospectively reviewed all patients undergoing surgery for frontal lobe epilepsy at a single tertiary center over a 15-year period. Patients were excluded if they had undergone previous brain surgery, if the duration of their follow-up was <6 months, or if they carried a diagnosis of a progressive neurologic disorder. All patients received MRI and electroencephalography 6 months after the surgery. The primary outcome examined was seizure freedom at last follow-up beyond the acute postoperative period (>1 week).

A total of 158 patients were included, with a mean follow-up duration of 4.3 years (range, 0.5–15.7 years). Mean age at surgery was 20.4 years, with a mean duration of epilepsy of 12 years. In terms of pathology, the specimens removed were classified as malformations of cortical development (MCD) in 59%, tumor in 10%, encephalomalacia from stroke or trauma in 9%, normal in 10%, and other in 12%.

The proportion of patients achieving seizure freedom was 66% [95% confidence interval (CI), 62–68] at 1 year, 52% (95% CI, 48–56) at 2 years, and 44% (95% CI, 39–49) at 5 years. The median time to recurrence in those who experienced seizures was 3 months. In 17% this recurrence occurred in the setting of antiepileptic drug withdrawal, and in an additional 13% it occurred in the setting of physiologic stress (e.g., sleep deprivation or illness).

A shorter duration of epilepsy was associated with better seizure outcomes using multivariate modeling, including when using duration cutoffs of 2, 5, or 10 years. Better seizure outcomes were observed in children undergoing surgery compared with adults, but earlier surgery led to better outcomes across all age groups. This benefit of lesional surgery was also found to be independent of pathologic diagnosis. Other independent predictors of poor prognosis that have been previously defined and were confirmed in the cohort included left-sided surgeries and acute postoperative seizures (in the first week following surgery).

This study once again demonstrates the benefit of surgery in focal epilepsy. These medically refractory patients were still seizure free at 5 years nearly 50 percent of the time, which is a remarkable success rate comparable with previous investigations. Limitations include the retrospective nature of this study and the natural biases of patient selection at a single institution. While a randomized trial would be welcome to prove the benefit of early surgery in frontal lobe epilepsy, for now clinicians and their patients with frontal lobe epilepsy should consider earlier resective surgery when it becomes clear that they are refractory to commonly used antiepileptic medications.