Changes in lingual-alveolar contact pressure during speech over six months in amyotrophic lateral sclerosis

This study compared lingual-alveolar contact pressures during consonant (LACP-Sp) production between adults with and without amyotrophic lateral sclerosis (ALS) over three visits within six months and assessed the relationship between LACP-Sp and speech intelligibility.

Ten people with ALS and nine without read sentences with lingual-alveolar consonants embedded as LACP-Sp was recorded. Recordings were done at study entry, then three and six months after entry. Six of ten with ALS had bulbar symptoms detected in clinical encounter at the time of study enrollment (ALS-B); the remaining four had only spinal symptoms (ALS-S).

Main and interaction effects varied across experimental stimuli. However, the pattern of results from the ANOVAs indicated that the ALS-B had lower LACP-Sp values than the other groups. Time main effects were present indicating a reduction in LACP-Sp. However, there were interaction effects for fricatives and/l/, with the ALS-S group demonstrating greater reduction over time than the other groups. Word intelligibility had moderate to large correlations with LACP-Sp but confidence intervals were broad and only a few were statistically significant.

LACP-Sp does decrease over time in people with ALS and may reflect a general weakening of the tongue. Confirmation of these group changes will require assessment with a larger sample size.