In a Case of Alzheimer’s Disease, Aggressiveness Disappeared after an Infarction in the Anterior Thalamic Nucleus

Case Report In June 2002, a right-handed woman was admitted to the hospital at the age of 91 and showed intense aggressiveness. She was diagnosed as having Alzheimer’s senile dementia at the age of 88 and was associated with delusion and hostility towards the family. She often appeared angry and displayed resistance and violence towards caregivers. At the age of 95, a slightly unstable posture was observed when walking or sitting. A brain MRI was performed and diffusion-weighted imaging showed hyperintensity in a small region within the right basal ganglia, adjacent to the right lateral ventricle ( fig. 1 a). We diagnosed acute brain infarction and administered treatment for 2 weeks. A later MRI ascertained that the infarction caused a restricted lesion in the right anterior thalamic nucleus (ATH) ( fig. 1 b, c). After the infarction, the patient’s emotional and behavioral aggressiveness disappeared; she talked gently with the care staff and received assistance without refusal or aggression. In an assessment based on the Behavioral Pathology in Alzheimer’s Disease Rating Scale [2] , the scores of threat, violence, anxiety and fear decreased by at least 2 points compared to those before the infarction. The Mini-Mental State Examination scores were 5/30 in 2005 before the infarction, 2/30 in July 2006 after the infarction and 17/30 in April 2007. She was discharged in May 2007 and severe aggressiveness has not recurred. Introduction Emotional disturbances including aggressiveness, behavioral abnormalities and violence cause difficulty in the treatment and care of patients with Alzheimer’s disease. Although neuroleptics, including atypical antipsychotics, often alleviate these problems [1] , the mechanisms underlying the aggressive behavior are still unknown in this disease. Published online: November 17, 2008