Longitudinal changes in discourse production in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a multisystem disease that significantly impacts communication as a function of changes in motor speech, cognition, and language skills. Although discourse tasks have been used to assess language in a variety of acquired disorders, little work to date has been published on changes in discourse in ALS and even less work has evaluated these changes with disease progression. In the present study, discourse samples (gained from a picture description task) as well as standardized language test measures obtained from 16 individuals with ALS without dementia and 12 healthy controls (collected over a duration of 24 months). Discourse samples were analyzed for both productivity and content. Results indicate that there were no differences for ALS versus controls for any of the standardized language tests. However, findings suggest that discourse analysis methods may be more sensitive for identifying subtle language deficits in ALS. Overall, discourse productivity appears less impaired than discourse content for individuals with ALS. Although there was a general trend for decline in language performance over the study duration, there was the suggestion of subgroups of language performance among ALS participants. The results suggest that subtle cognitive language deficits that affect discourse emerge early in ALS and progress with disease progression.