Dysphagia linked to clinical phenotype and disease progression in spinocerebellar ataxia type 3

Spinocerebellar Ataxia type 3 (SCA3) is a widely recognized autosomal dominant disorder characterized by cerebellar ataxia, particularly prevalent in China. Dysphagia frequently arises in SCA3 and other neurological disorders, representing a significant threat to patient survival.

Examining the Prevalence of Dysphagia among SCA3 Patients and Its correlation with Clinical phenotype and Disease Progression.

We retrospectively analyzed 183 SCA3 patients, divided into dysphagia and non-dysphagia groups. Dysphagia, as an item within INAS, was assessed by ataxia specialists primarily based on patient-reported symptoms, supplemented by caregiver or family input when available. Spearman's rho tested factor associations with dysphagia, logistic regression identified dysphagia risk factors, and multivariable linear regression assessed dysphagia's effect on ataxia severity. Kaplan-Meier curves with first derivative fitting explored dysphagia progression over the disease duration.

The study found 77.0% of SCA3 patients had dysphagia, with disease duration most strongly linked to its onset (r = 0.456, p < 0.001). Sex (p = 0.001; OR = 4.69, 95% CI = 1.85 to 11.88), AAO (p = 0.031; OR = 0.93, 95% CI = 0.87 to 0.99), SARA scores (p = 0.034; OR = 1.12, 95% CI = 1.01 to 1.25), and disease duration (p < 0.001; OR = 1.34, 95% CI = 1.14 to 1.57) were independent dysphagia risk factors. Dysphagia also affected SARA scores (p = 0.048). Dysphagia progression rate peaks within the first decade of disease onset, reaching maximal velocity at 6.5 years, with a median time to dysphagia onset of 9 years.

In China, dysphagia frequently occurs in SCA3 patients and can impact the severity of ataxia. The prevalence of dysphagia varies as the disease advances. These findings highlight the importance of timely intervention for dysphagia in SCA3 patients, particularly during the late stages of the first decade.