Pathological generosity: an atypical impulse control disorder after a left subcortical stroke

Changes in socio-emotional behavior and conduct, which are characteristic symptoms of frontal lobe damage, have less often been described in patients with focal subcortical injuries. We report on a case of pathological generosity secondary to a left lenticulocapsular stroke with hypoperfusion of several anatomically intact cortical areas. A 49-year-old man developed excessive and persistent generosity as he recovered from a left lenticulocapsular hematoma. His symptoms resembled an impulse control disorder. (99m)Tc-HMPAO SPECT demonstrated hypoperfusion mostly in the ipsilateral striatum, dorsolateral, and orbitofrontal cortex. This case study adds pathological generosity to the range of behavioral changes that may result from discrete unilateral lesions of the lenticular nucleus and nearby pathways. In our particular case, post-stroke pathological generosity was not ascribable to disinhibition, apathy, mania, or depression. Because pathological generosity may lead to significant distress and financial burden upon patients and their families, it may warrant further consideration as a potential type of impulse control disorder.