Motor speech characteristics and timing in persons with ALS

By L.J. Ball and D.R. Beukelman


The purpose of our inquiry is to identify communication characteristics that may be utilized in early identification of bulbar symptoms and to monitor progression of bulbar dysfunction in patients with Amyotrophic Lateral Sclerosis (ALS). Early identification of bulbar dysfunction assists physicians with enrolling individuals in clinical trials and speech-language pathologists in clinical management decisions. A database of clinic visits from forty-nine persons with ALS was developed and formed the basis for these analyses. Results indicate that speech intelligibility alone is not an effective early identifier of the speech symptoms associated with bulbar ALS. Our data identified that the strongest early predictors of bulbar speech dysfunction must include a measure of speaking rate. Participants demonstrated a sharp decline in intelligibility associated with a decline in speaking rate (at approximately 100-120 words per minute). This sharp decline in intelligibility occurred regardless of the type of onset (bulbar, spinal, or mixed). The number of months post diagnosis of ALS did not prove predictive of speech loss in any of the types (bulbar, spinal, mixed).