The degenerative dysarthrias: a window into critical clinical and research issues

Although diversity of symptoms and urgency of needs pose many challenges, management of the degenerative dysarthrias is a crucial aspect of clinical practice. The purpose of this article is to review current research literature on selected degenerative dysarthrias including those associated with Parkinson's disease, multiple sclerosis, and amyotrophic lateral sclerosis. These dysarthrias are prevalent yet represent distinct patterns of underlying neuropathology, symptoms, age of onset, and rate of progression. Literature searches including the period 1997-2006 yielded 148 different studies reporting data on communication issues related to dysarthria. By far the largest category of studies was that which provided a basic description of speech production including the neurophysiologic, acoustic, or perceptual properties of dysarthria. Other categories included management (assessment and treatment) and the psychosocial consequences of dysarthria. While the topic of management of degenerative dysarthria is a focused one, it provides a window into many issues critical to the field of communication disorders including fundamental properties of speech production, development of evidence-based treatment techniques, the staging of these techniques into an effective management sequence, and the psychosocial consequences of communication disorders along with techniques to maintain communicative participation in the face of degenerative conditions.