Early Frontal Executive Impairment as a Predictor of Subsequent Behavior Disturbance in Dementia

Abstract

To determine the extent to which frontal executive impairment early in the course of dementia is predictive of subsequent disturbed behavior. This was a prospective follow-up study set in the Memory Clinic, Leicester, United Kingdom. A patient cohort (N = 42) diagnosed with mild to moderate dementia was followed up between three and six years after initial assessment. Executive function at baseline was assessed using the The Cambridge Examination for Mental Disorders of the Elderly-Revised (CAMCOG-R) Executive Function score. Disturbed behavior and caregiver distress at follow-up were assessed on the Neuropsychiatric Inventory (NPI), Cohen-Mansfield Agitation Inventory (CMAI), and Dementia Apathy Interview and Rating (DAIR). After adjustment, the Executive Function score at baseline was predictive of disturbed behavior and caregiver distress (NPI, CMAI, DAIR) at follow up, with higher levels of executive impairment associated with higher levels of disturbance/distress. Baseline measures of global cognitive impairment (Mini-Mental State Exam, CAMCOG) were not predictive of subsequent disturbed behavior or caregiver distress. Executive impairments identifiable relatively early in the clinical course of dementia are predictive of disturbed behavior and associated caregiver distress at long-term follow-up, which supports the view that executive dysfunction is important in the etiology of these problems.