Epilepsy in the frontal lobes: Neuropsychological characteristics

The disruption of cognitive functions by epileptic discharges arising from specific foci in the frontal regions have rarely been described, probably reflecting the previous difficulties in the collection of adequately described groups. We describe the neuropsychological consequences of frontal lobe epilepsy dependent on the epileptic focus in the frontal region. A group of 74 subjects with frontal lobe epilepsy (FLE) was assessed; 30 had a dorsolateral dysfunction (17 left, 13 right), 11 had mesial (7 left, 4 right), 10 had orbitofrontal (5 left, 5 right), 10 had motor/premotor (5 left, 5 right), and 13 had extensive (i.e., more than one frontal region, 8 left, 5 right) dysfunction. Comparisons were made between the groups on a battery of neuropsychological measures believed to be sensitive to frontal lobe dysfunction. The results indicated only 2 of 26 variables to be specifically impaired dependent on the location of epileptic foci in the frontal lobe (p < 0.05), an observation that emphasizes the difficulty in assessing functions in this region and the consequences that rapidly diffusing epileptic activity may have on cognitive function. We conclude that documentation of consistent deficits associated with frontal lobe epileptic loci will prove difficult.