Supplementary Material for: Differential Progression of Dysphagia in Heredity and Sporadic Ataxias Involving Multiple Systems

Sporadic ataxia affecting multiple systems, such as cerebellar, extrapyramidal, and autonomic systems, is known as multiple system atrophy cerebellar type (MSA-C), while similar multisystem involvements are seen in certain types of hereditary ataxia, such as spinocerebellar ataxia type 3 (SCA3). Dysphagia is a common symptom that can predispose to aspiration pneumonia, a major cause of death in patients with these diseases. Although the progressions of dysphagia in patients with MSA-C have been reported sporadically, those in SCA3 have not been reported. We retrospectively compared the results of repetitive videofluoroscopic examinations in patients with SCA3 (n = 6) and in those with MSA-C (n = 7). The result showed that the gross progression of dysphagia was significantly slower in patients with SCA3 than in those with MSA-C, but the maximum progression speeds were not significantly different. The dysphagia severities were not associated with impaired activity of daily living evaluated by the Barthel index in MSA-C, but were associated in SCA3. Despite the small number of patients enrolled, these data suggest that physicians should monitor swallowing functions in patients with SCA3 after mild dysphagia develops because it may progress as rapidly as it does in MSA-C.