Prosody impairment and associated affective and behavioral disturbances in Alzheimer's disease

We examined the ability to produce, repeat, and comprehend emotional prosody in 20 patients with Alzheimer's disease (AD) and in 11 elderly normal control subjects. In addition, caregivers of AD patients completed affective and behavioral measures with reference to the patient. Relative to control subjects, comprehension of emotional prosody was marginally impaired in mildly demented AD patients, whereas production, comprehension, and repetition of emotional prosody were significantly impaired in moderately demented AD patients. The moderately demented patients performed significantly poorer than the mildly demented patients on the production and repetition tasks. In contrast, there was no significance difference between the two groups on the prosody comprehension task. Additional analyses revealed an inverse relationship between the ability to correctly produce and repeat emotional prosody and the frequency of agitated behaviors and depressive symptomatology in moderately demented patients. This latter findings suggests that the inability to communicate emotional message is associated with disturbances in mood and behavior in AD patients. Implications for the management of disruptive behavior in agitated and aprosodic AD patients include the development of caregiver sensitivity to unexpressed emotion and caregiver assistance with emotional expression.