Case report: acquired antisocial personality disorder associated with unilateral left orbital frontal lobe damage.

We report on our analysis of a patient who developed personality changes which strongly resembled an antisocial personality disorder after surgical resection of a pituitary tumor. Despite behavioral changes that were obvious to friends, family and health care professionals, formal neuropsychological and personality testing revealed no specific cognitive deficits or psychopathology. We hypothesize that damage to a circumscribed region of the left orbitofrontal cortex, illustrated by magnetic resonance imaging, underlies these personality alterations. In contrast to previous reports, which ascribe such personality changes to bilateral frontal lobe injury, we suggest that unilateral frontal lobe damage alone may have resulted in the development of this syndrome.