Management of Dysarthria in Amyotrophic Lateral Sclerosis
Kathryn M. Yorkston, Ph.D., BC-NCD, Department of Rehabilitation Medicine, University of Washington, Seattle, WA.
David Beukelman, Ph.D., Department of Special Education and Communication Disorders, University of Nebraska, Lincoln, Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska, Omaha, NE.
Laura Ball, Ph.D., Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska, Omaha, NE.
Summary
This article describes intervention for dysarthria associated with amyotrophic lateral sclerosis (ALS). Five critical periods are presented including a stage with normal speech, detectable speech disturbance, behavioural intervention, use of augmentative communication, and loss of useful speech. Intervention strategies at each of these stages are outlined with the goal of maintaining functional communication regardless of the severity of dysarthria.
ALS is a rapidly progressive degenerative disease of unknown etiology involving the motor neurons of both the brain and spinal cord.1 The symptoms characteristic of ALS are generally classified by site of involvement (that is, upper motor neuron versus lower motor neuron) and by whether spinal nerves (those innervating the arms and legs) or bulbar nerves (those innervating the muscles of speech and swallowing) are involved. The motor speech impairment associated with ALS is classified as a mixed dysarthria showing features associated with both spasticity (lack of fine control) and flaccidity (weakness).2
Loss, or potential for loss, of communication is one of the most distressing aspects of ALS. Approximately 80% of persons with ALS experience such severe speech impairments that they require augmentative communication strategies to meet their daily communication needs. These communication impairments are progressive. Those with bulbar signs experience relatively early loss of the speech while those with spinal signs lose their speaking effectiveness somewhat later in the course of the disease. Maintenance of functional communication skills either in the form of natural speech or augmentative communication strategies is an important intervention goals. There are few aspects of adult life that are not affected by reduced communication capabilities. This article describes principles of intervention for dysarthria associated with ALS. Symptoms and intervention for five stages of dysarthria severity are also outlined.
Principles of Intervention
Communication competence allows persons with ALS to maintain their ability to guide, direct and influence the management of both medical and personal aspects of their lives.3
The first intervention principle is to maintain functional communication throughout the course of the disease. This principle is most often violated when patients, their families and professionals delay their decision-making until the individual can no longer speak, before pursuing alternative communication methods. This delay is commonly the result of inadequate information and education.
The second, and related principle of management is timely intervention. To accomplish this, professionals need to systematically evaluate the speech performance of persons with ALS and to inform them regarding predictors of impending communication failure. With this information, persons with ALS and their families can prepare themselves to make the necessary intervention decisions to become aware of the availability of services that they need in the future. A chief goal is to help the patient and family become informed consumers of medical and technological services.
The third principle of intervention is a system to identify "critical periods" when intervention is needed promptly and briefly. These critical points are periods when the person's capabilities have changed and communication needs are not being met, but before fatigue and weakness are overwhelming. Identification and anticipation of these critical periods requires the staging of intervention so that current needs are met and future needs anticipated.
Staging Intervention
The following section outlines intervention in five stages of dysarthria severity. These stages that define critical periods of intervention are summarized in