Stereotactic amygdaloidotomy for aggressive behaviour.

Amygdaloidotomy was performed bilaterally on 15 and unilaterally on three patients exhibiting severe aggressive or self-mutilating behaviour. Nine subjects (50%) were improved a year after operation; improvement was maintained in seven (39%) for periods ranging from 27 months to nearly six years. Four non-epileptic cases had convulsions during the period of review; one of them has a persistent mild hemiparesis dating from the postoperative period. There was a tendency for epileptics to respond better than non-epileptics and for mentally retarded patients to respond poorly, but none of the differences was statistically significant.