Explosive aggression, frontal deficits linked
in epileptic subjects

Unprovoked aggressive episodes are more common among people with temporal lobe epilepsy than among non-epileptic individuals. However, only a minority of people with temporal lobe epilepsy experience episodes of abnormal aggression, and a new study may help elucidate the difference between those who do and do not exhibit this behavior.

Friedrich Woermann and colleagues used quantitative MRI to examine the brains of 24 individuals with temporal lobe epilepsy and a history of unprovoked aggression, 24 patients with temporal lobe epilepsy but no history of abnormal aggression, and 35 controls with neither condition. The researchers report that the patients with temporal lobe epilepsy and aggression exhibited a decrease of gray matter, most markedly in the left frontal lobe, compared with control subjects and with patients with epilepsy but without a history of aggressive episodes.

The researchers say their findings are similar to those of earlier studies showing reduced prefrontal glucose metabolism in murderers (see related article, Crime Times, 1995, Vol. 1, No. 1-2, Page 1), and abnormalities in the frontal lobes of repetitively violent patients with learning disabilities. "These findings," they say, "might suggest a localized reduction in frontal gray matter volume or neuronal density to be common to different syndromes involving dyscontrol or affective aggression."

The findings are also interesting in light of a recent report by Adrian Raine et al. (see related article, Crime Times, 2000, Vol. 6, No. 2, Page 1) of a link between prefrontal deficits and antisocial personality disorder.

"Reduction of frontal neocortical grey matter associated with affective aggression in patients with temporal lobe epilepsy: an objective voxel by voxel analysis of automatically segmented MRI," Friedrich G. Woermann, Ludger Tebartz van Elst, Matthias J. Koepp, Samantha L. Free, Pamela J. Thompson, Michael R. Trimble, and John S. Duncan, Journal of Neurology, Neurosurgery, and Psychiatry, Vol. 68, No. 2, February 2000, pp. 162-169. Address: Friedrich G. Woermann, Epilepsy Research Group, Institute of Neurology, Department of Clinical Neurology, Queen Square, London WC1N 3BG, U.K.