Huntington's disease is characterized by motor and behavioral symptoms as well as cognitive decline. Apathy is a common behavioral symptom, and its severity is related to disease progression. It has been suggested that Huntington's disease gene expansion carriers (HDGECs) are unaware of the signs and symptoms of the disease, which may account for their own level of awareness of their apathy. Therefore, the authors investigated the level of agreement on the degree of apathy severity between HDGECs and their proxies by using a self-report questionnaire. A total of 109 REGISTRY participants (premotormanifest, N=31; early motormanifest, N=49; and late motormanifest, N=29) and their proxies completed the Apathy Evaluation Scale. The authors used the Wilcoxon signed-rank test to assess whether gene expansion carriers and their proxies agreed on apathy severity. Scores on the Apathy Evaluation Scale significantly increased from the early motormanifest stage to the late motormanifest stage. Premotormanifest carriers scored themselves significantly higher on the Apathy Evaluation Scale than their proxies, whereas no differences were found between all motormanifest carriers and their proxies. Apathy severity increases in the motormanifest stages of Huntington's disease. HDGECs can adequately assess their level of apathy on a self-report questionnaire. These results also suggest that slight changes in the degree of apathy among premotormanifest gene expansion carriers remain unnoticed by their proxies.
Keywords: Huntington’s Disease; Neuropsychiatric Rating Scales.