CEREBRAL BLOOD-FLOW CORRELATES OF APATHY IN ALZHEIMER-DISEASE

Background: Apathy is a pervasive noncognitive neuropsychiatric distur bance in Alzheimer disease, which causes significant caregiver distres s. The neuroanatomical substrate of apathy is not well understood. Obj ective: To study the relationship between regional cerebral blood flow and the presence and severity of the personality disturbance, apathy, in individuals with Alzheimer disease. Design: Analysis of the relati onship between regional cerebral blood flow as measured by single phot on emission computed tomography and severity of apathy as measured by the Neuropsychiatric Inventory using an analysis of variance design. W e examined regional cerebral perfusion alterations as measured by xeno n Xe-133-calibrated technetium Tc 99m hexamethyl-propyleneamine-oxime single photon emission computed tomography in relation to the presence and severity of apathy. Setting: The neurology clinics of the Univers ity of California, Los Angeles, UCLA School of Medicine, and Harbor-UC LA Medical Center. Participants: Thirty-one community-dwelling patient s fulfilling National Institute of Neurological and Communicative Diso rders and Stroke-Alzheimer's Disease and Related Disorders Association diagnostic criteria for probable Alzheimer disease who had a single p hoton computed tomographic scan performed within 3 months of administr ation of the Neuropsychiatric Inventory. Results: The presence of apat hy was associated with more severe prefrontal and anterior temporal dy sfunction. These regional cerebral perfusion relationships with apathy were independent of cognitive decline except in the dorsolateral pref rontal cortex. Conclusions: These results demonstrate the association of apathetic syndromes with prefrontal and anterior temporal regional brain dysfunction and are consistent with similar findings preciously reported in other disorders.