Apathy symptom profile and behavioral associations in frontotemporal dementia vs dementia of Alzheimer type.

BACKGROUND Apathy is a common and significant problem in patients with dementia, regardless of its cause. Observations about frontosubcortical circuit syndromes indicate that apathy may have affective, behavioral, or cognitive manifestations. OBJECTIVES To explore whether the apathy manifested in frontotemporal dementia (FTD), with its predominantly anterior brain neuropathologic features, differs from the apathy in dementia of Alzheimer type (DAT), with its predominantly hippocampal- and temporoparietal-based neuropathologic features, and to determine whether other behavioral disturbances reported in frontosubcortical circuit syndromes correlate with apathy. DESIGN Analyses included individual items within Neuropsychiatric Inventory subscale items. Items of the apathy/indifference subscale were designated by consensus as affective (lacking in emotions), behavioral (inactive, chores abandoned), or cognitive (no interest in the activities of others). Proportions of correlated nonapathy Neuropsychiatric Inventory items were calculated. SETTING Several neurology specialty clinics contributed to our data set. PARTICIPANTS A total of 92 participants with FTD and 457 with DAT. MAIN OUTCOME MEASURES The Neuropsychiatric Inventory was analyzed. RESULTS Apathy was more prevalent in patients with FTD than in those with DAT, but when present, the specific apathy symptoms associated with both types of dementia were rarely restricted to 1 of the 3 domains of apathy. Dysphoria concurrent with apathy was unique to the DAT group and negatively correlated in the FTD group. Participants with affective apathy more frequently copresented with an orbital frontosubcortical syndrome in FTD (impulsivity and compulsions). Affective apathy also copresented with uncooperative agitation, anger, and physical agitation in both types of dementia. CONCLUSIONS Apathy is common in patients with FTD and DAT, although it is more common in those with FTD. When present, it usually involves changes in affect, behavior, and cognition. It is associated with behaviors that have previously been shown to affect patient safety, independence, and quality of life.