Comprehension of complex discourse in different stages of Huntington's disease.

BACKGROUND: Huntington's disease not only affects motor speech control, but also may have an impact on the ability to produce and understand language in communication. AIMS: The ability to comprehend basic and complex discourse was investigated in three different stages of Huntington's disease. METHODS & PROCEDURES: In this experimental group study, 18 patients with Huntington's disease completed a test that assessed basic language abilities as well as tests from a battery of tasks that explored the ability to comprehend more complex information. The test battery assessed the ability to comprehend logico-grammatical sentences, ambiguous information and inferred meaning on sentence and discourse levels. OUTCOMES &
RESULTS: In comparison with results from pair-matched participants in a control group, matched for gender, age and education, the group of individuals with Huntington's disease had significantly more problems with all tasks requiring more complex cognitive processing. There was a correlation, as well as tendencies towards correlations, between results in the group of individuals with Huntington's disease and stage of the disease. However, results within the stage groups were heterogeneous, and some individuals in an early stage of the disease sometimes performed as well as others in a late stage. CONCLUSIONS & IMPLICATIONS: It is likely that, in complex discourse tasks, individual differences in cognitive capacity may contribute and override other differences related to stage of disease. These results indicate that it is important to assess comprehension even in early stages of Huntington's disease, with tests that are sensitive to subtle language disorders, to reduce communication problems for the individuals concerned and their conversational partners.