Speech Movement Measures as Markers of Bulbar Disease in Amyotrophic Lateral Sclerosis.

Purpose: The goal of this study was to identify the effects of amyotrophic lateral sclerosis (ALS) on tongue and jaw control, both cross-sectionally and longitudinally. The data were examined in the context of their utility as a diagnostic marker of bulbar disease.

Method: Tongue and jaw movements were recorded cross-sectionally (n = 33 individuals with ALS, 13 controls) and longitudinally (n = 10 individuals with ALS) using a three-dimensional electromagnetic articulography system during the production of the sentence Buy Bobby a puppy. The movements were examined for evidence of changes in size, speed, and duration and with respect to disease severity and time in the study.

Results: Maximum speed of tongue movements and movement durations were significantly different only at an advanced stage of bulbar ALS compared with the healthy control group. The longitudinal analysis revealed a reduction in tongue movement size and speed with time at early stages of disease, which was not seen cross-sectionally. As speaking rate declined, tongue movements decreased in maximum speed, whereas jaw movements increased in maximum speed.

Conclusions: Longitudinal analyses of sentence-level kinematic data show their sensitivity to early bulbar impairment. A change in articulatory kinematics can serve as a useful diagnostic marker for bulbar ALS and to track bulbar disease progression in a clinical setting.