Researchers report that evaluating a person’s control of tongue movement during speech can help to diagnose bulbar disease, especially in its early stages, in patients with amyotrophic lateral sclerosis (ALS).
ALS affects motor neurons in the brain, brainstem, and spinal cord. If patients show alterations in speech or swallowing abilities they are diagnosed with bulbar ALS. Indeed, as ALS disease progresses, 85 percent of patients exhibit bulbar disease.
The study, “Speech Movement Measures as Markers of Bulbar Disease in Amyotrophic Lateral Sclerosis,” published in the Journal of Speech, Language, and Hearing Research, aimed to determine if the mechanics of speech, as seen in tongue and jaw control, could be used as diagnostic markers for bulbar disease in ALS.
The standard clinical assessment of bulbar disease can be done by examination of the strength, range, speed of movement, and symmetry of oral musculature. However, these measurements can be subjective.
The authors proposed that mechanistic measurements of the tongue and jaw could allow the evaluation of independent structures involved in speech. This process could improve the assessment of a motor speech disorder resulting from ALS.
Researchers asked ALS patients to say the sentence Buy Bobby a puppy, while they recorded patients’ tongue and jaw movement. Information gathered allowed them to assess changes in movement size, speed, and duration according to disease severity.
Results showed that tongue movements’ maximum speed and duration were significantly different in patients with advanced stage bulbar ALS when compared with healthy controls.
At early stages of the disease, a reduction in the size and duration of tongue movements was seen, while as speaking ability further deteriorated, the speed of tongue movements further slowed and the speed of jaw movements increased.
These results indicated that tongue movement can be an appropriate marker of early changes in bulbar function. “A decrease in tongue movement size with disease progression may serve as a potential diagnostic marker for early detection of bulbar involvement,” the researchers wrote.
They also highlighted the importance of more studies to develop a protocol for detecting early signs of bulbar ALS, and for documenting disease progression over time and improving clinical trials.