Relationship between speech and swallowing disorders in patients with neuromuscular disease

The intelligibility of monosyllabic speech, word speech, and conversational speech was evaluated in 113 dysarthric speakers, and the presence and severity of swallowing disorders were evaluated using videofluoroscopic and bedside examinations. The results revealed a high correlation between swallowing function and all levels of speech intelligibility. Furthermore, the prevalence of concomitant dysphagia in dysarthric patients was quite high regardless of the primary etiology and time elapsed since the onset. However, the relationship between the two functions is more complex than is initially apparent. The prevalence and severity of dysphagia vary markedly according to the type of dysarthria. Patients in the flaccid, spastic, and mixed categories encompass a broad range of severity levels with many individuals being severely impaired, while patients in the ataxic, hypokinetic, and unilateral upper motor neuron categories seldom have severe concomitant swallowing problems. Furthermore, the correlation coefficient between conversational intelligibility and swallowing function varies considerably according to the type of dysarthria. The correlation was not significant in the flaccid, hypokinetic, and UUMN dysarthria groups. Based on these findings, we discuss herein the clinical management of dysarthric patients with dysphagia.