Abstracts

Frontal lobe epilepsy (FLE) is the most common form of extratemporal epilepsy, comprising between 15 to 30 percent of patients with medically refractory seizures. Despite its prevalence, few studies exist describing the cognitive and behavioral characteristics of FLE. Past research suggests that patients with FLE demonstrate significant impairments in executive functioning, especially in cognitive inhibition. Patients with FLE also report higher levels of depression and experience more social behavioral problems than their healthy counterparts. What is unclear is whether problems with cognition inhibition, mood, and behavior differ depending on the side of the seizure focus and/or the presence or absence of a structural lesion on MRI. This investigation explored cognitive inhibition, mood, and behavior in patients with FLE and addressed whether the side of the seizure focus and/or lesion status influence performances. Participants were 15 patients with FLE documented by EEG and clinical history. Five patients had left and 10 had right seizure foci. Eight patients had MRI-confirmed lesions, whereas seven were nonlesional. All patients completed the Color-Word Interference Test (CWIT) of the Delis-Kaplan Executive Functions System (DKEFS), the Frontal Systems Behavior Scale (FrSBe), and the Beck Depression Inventory-II. Patients with FLE, as a unified group demonstrated mild impairments on the CWIT Inhibition/switching condition of the DKEFS and reported mild levels of depression. Significant subgroup differences emerged, however, when the side of the seizure focus and lesion status were considered. Patients with left FLE showed poorer cognitive inhibition and reported higher levels of depression than those with right FLE. In addition, patients with structural lesions on MRI demonstrated poorer cognitive inhibition and reported higher levels of apathy on the FrSBe than patients without structural lesions. Correlational analyses in the whole sample revealed that higher levels of self-reported executive dysfunction were associated with poorer cognitive inhibition on formal testing. Neither variable correlated with self-reported depression. In patients with FLE, cognitive inhibition, mood, and behavior may differ depending on the side of the seizure onset and the presence or absence of a structural lesion. Thus, considering these patients as a unified group may obscure important cognitive and behavioral differences. Furthermore, there appears to be a significant relationship between self-reported executive dysfunction and actual test performance in patients with FLE, regardless of the side of seizures or lesion status. (Supported by the Epilepsy Foundation through the generous support of the American Epilepsy Society and the Milken Family Foundation.)