Velopharyngeal Function During Speech Production in Amyotrophic Lateral Sclerosis

Abstract

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that leads to decreased muscle function resulting in problems with movement, breathing, swallowing, and speech. In the United States, approximately 5,600 people are diagnosed with ALS annually (ALS Association [ALSA], 2010). ALS can attack muscles all over the body, including those in the velopharynx, a muscular valve-like structure located at the back of the oral cavity. In a healthy adult, the velopharynx closes off the passageway to the nasal cavity during speech production to direct air through the mouth rather than through the nose (except during productions of /m/, /n/, and /ng/). Speech that is produced with an open velopharynx sounds indistinct and has a nasal quality. Many people with ALS experience difficulty producing clear, articulate speech because their velopharynx remains open for the majority of speech sounds. As a result, their speech eventually becomes unintelligible. Currently, there is little information available about the function of the velopharynx in people with ALS. The purpose of this study is to describe velopharyngeal function during speech in people with ALS. This information will be compared with their speech rate and intelligibility scores, both common measures used to document speech decline.