Sexual Behavioral Disinhibition Associated with Nucleus Lentiformis Lesion: A Forensic Neuroscience Perspective Through a Case.

Organic brain disturbances particularly related to frontal cortex structures and subcortical areas including the basal ganglia may play a role in behavioral disinhibition disorders. Kluver-Bucy syndrome (KBS), which is one of the better knowns of these syndromes, includes hyperorality, visual agnosia, and hypersexuality, has been reported to occur after temporal lobe and amygdala lesions; however, several patients who had focal lesions in areas other than the temporal cortex and amygdala have been reported to present partial KBS symptoms. Nucleus lentiformis refers to a large portion of the basal ganglia including the putamen and globus pallidus, and specific structures within this broad area are known to be important for reward and value-based decision making. To date, KBS symptoms including hypersexual behavior associated with nucleus lentiformis lesions have never been reported. Here, we present a 38-year-old male patient who developed increased sexual interest and hyperorality after infarctions in the right lenticular nucleus and right occipitotemporal region and committed a first-degree sexual assault. He was sent to our institution for the assessment of criminal responsibility to the index sexual crime. According to a comprehensive and thorough forensic psychiatric evaluation, he was diagnosed as having an organic personality disorder with partial KBS symptoms. To the best of our knowledge, this is the first reported case of deviant sexual behavior and hyperorality developing after nucleus lentiformis infarction. We aimed to discuss possible neurobiologic explanations of late-onset deviant sexual behavior, which resulted in sexual criminal behavior following a cerebrovascular infarction.