Patients with Huntington Disease (HD) show poor self-awareness of a variety of symptoms. Previous research in HD has primarily examined awareness of motor symptoms, whereas less attention has been given to unawareness of cognitive function and behavioural disorders. This study aim to assess self-awareness of executive deficits in HD and to explore the association between impaired awareness, cognition (executive function and memory) and evolution of the disease.
Self-awareness was tested in 17 patients with HD (8 male, age=50.5 ± 9.8 years) at early stage of the disease (mean TFC 11.7) by comparing patient and family ratings using the Dysexecutive Questionnaire (DEX) with five-factor factorial structure (Inhibition, Intentionality, executive memory, negative and positive affect). Executive and memory functions were assessed by different standardised neuropsychological tests included in cognitive protocol Registry 3. Finally, we extracted the volume of the different striatal substructures (left and right caudate, putamen and nucleus accumbens) as a neuroanatomical signature of disease progression in HD.
Statistical analysis revealed a significant discrepancy between the DEX-Family and DEX-Patient specifically in the second factor of DEX (intentionality). This factor contains items about disinhibition, aggression, euphoria, lack of insight and social conscience. We also found that poor insight in this area measured by DEX is significantly and specifically related with the atrophy of the left caudate. None of the cognitive tests that were administrated showed significant correlation with unawareness.
Our results are consistent with previous literature, indicating that patients with HD generally overestimate their abilities. This study shows that the awareness of dysexecutive function in HD is not a general and uniform process, but is specific to certain symptoms (predominantly behaviours related with intentionality and disinhibition) and suggests the involvement of specific neuroanatomical substrates for unawareness in HD.