Researchers examined 145 patients within 3 to12 months following their stroke. None of the patients (average age of 60) had a previous history of stroke or depression. Forty-seven of the patients (32 percent) became unable to control anger or aggression as a result of the stoke. The Speilberger Trait Anger Scale (see attached) was used to assess the patients' pre-stroke and post-stroke status. Interviews included input from relatives living with the patients.
In addition, researchers examined brain lesions and found there was a correlation between the location of the brain lesion and the appearance of anger and aggression. The inability to control anger and aggression was frequently present when there was a presence of lesions affecting the frontal, lenticulocapsular, and pontine base areas.
"We think that the inability to control anger and aggression is more likely a symptom of brain injury rather than a reactive behavior secondary to stroke, even in patients with physical disabilities," said Jong S. Kim, MD, Department of Neurology, Asan Medical Center, Seoul, Korea. "Anger and aggression seems to be a behavioral symptom caused by disinhibition of impulse control that is secondary to brain lesions, although it could be triggered by other peoples' behavior or by physical defects." He said anger and aggression and another symptom common with recovering stroke patients is "emotional incontinence," which are sudden outbursts of emotions that seem out of proportion or inappropriate to the situation. The two symptoms tend to occur together and share similar lesion distribution.