Neuropsychological performance in frontal lobe epilepsy

The search for a special neuropsychological profile of frontal lobe epilepsy subjects (FLE) has so far led to inconclusive results. In this paper we compared the preoperative neuropsychological performance of FLE and temporal lobe epilepsy (TLE) subjects. We further investigated whether frontal lobe lesions of epileptogenic cause produce the same type of cognitive dysfunction as do tumours of the frontal lobe. Sixteen FLE subjects were compared to 16 TLE subjects as well as to a group of 10 subjects after the removal of frontal lobe tumors (TUM) and a healthy control group. A set of neuropsychological test measures routinely used for presurgical evaluation, an emotional conceptualization task and two associative learning tasks were administered. We found that subjects with frontal lobe damage were significantly impaired relative to controls on a wide range of cognitive functions independent of neurological cause. FLE subjects could hardly be discriminated from TLE subjects as both groups showed a similarly reduced level of neuropsychological performance. Our results demonstrate the devastating effect that frontal lobe epilepsy can have on cognitive functioning. Routinely used neuropsychological test measures lack the specificity to distinguish between frontal and temporal lobe epilepsy. Highly specialized measures are necessary to reveal differences.