Dysexecutive symptoms such as apathy, impulsivity and distractibility have been reported on clinical ground in HD. However previous studies have assessed dysexecutive behavioural disorders using clinical interview or nonspecific questionnaires incorporating other features resulting in highly variable evaluation with poorly defined performance indices. This study aimed to assess dysexecutive behavioural abnormalities in HD, using a validated instrument, the Behavioural Dysexecutive Syndrome Inventory (BDSI).

14 patients (mean age: 55.5 years; SD 12.4; range: 34–73; mean duration: 8.7 years; SD=7; range: 2–30; mean MMSE score: 25; SD=3.4) with clinically diagnosed and genetically confirmed HD, were included. The assessment of depressive symptoms (Montgomery Asberg Depression Scale) showed a mild depression in 7 patients.

The BDSI is a highly structured caregiver based interview which rates frequency and severity of 12 dysexecutive disturbances (global hypoactivity with apathy, hyperactivity, irritability-impulsivity, euphoria, perseverative behaviour; environmental dependency, social behaviour disorders). The analysis of individual performance was performed using cutoff scores at the 5% level using normative data obtained in 96 controls¹.

The prevalence of behavioural dysexecutive syndrome was high (50%; 95% CI: 24–76). The behavioural profile was characterised by the prominence of irritability (50%), hyperactivity (43%), apathy (29%), disinterest (22%) and difficulties for anticipation (14%).

This study based on the BDSI revealed in HD that behavioural dysexecutive disorders are: 1 frequent with a prevalence of 50%, 2 characterised by a specific profile with the prominence of irritability and hyperactivity-distractibility, 13 whereas the hypoactivity-apathy disorders were less frequent contrary to most other degenerative disorders.

1 Godefroy et al. Ann Neurol. 2010