Clinical Scales Predict Significant Videofluoroscopic Dysphagia in Machado Joseph Disease Patients

Although aspiration is one of the main causes of death in SCA, such as SCA3/Machado Joseph disease (SCA3/MJD), clinical studies on dysphagia are lacking for these diseases. The aims of this study were to characterize dysphagia in SCA3/MJD through videofluoroscopy (VF) of swallowing, correlate VF with disease severity criteria and weight loss, and determine the clinical criteria cutoffs for performing VF in the clinical routine, in order to detect aspiration.

A cross-sectional study on 34 SCA3/MJD patients was performed. Clinical and molecular data, as well as body mass index (BMI), were obtained. Neurological scales, such as the Scale for the Assessment and Rating of Ataxia (SARA), and the Swallowing Quality of Life (SWAL-QOL) questionnaire were applied. The VF scores, Dysphagia Outcome and Severity Scale (DOSS) and penetration/aspiration scale (PAS), were obtained: Moderate-to-severe scores were grouped as "significant dysphagia."

Overall, 31 of 34 individuals showed abnormal scores at VF. SARA, BMI, and the domain "eating duration" of SWAL-QOL correlated with VF: Their relation to significant dysphagia (DOSS <4 points or PAS >3) was evaluated through receiver operating characteristic curves. A sensitivity of 100% was equivalent to a cutoff of 15 points on SARA score, 23.72 kg/m² on BMI, and 60% on eating duration-SWAL-QOL (P < 0.05).

Significant dysphagia was not related to age at onset, disease duration, or CAG repeat expansion, but with SARA scores, lower BMI, and the domain eating duration of SWAL-QOL. As a guideline for preventing aspiration, we suggest that SARA scores greater than 15 or eating duration-SWAL-QOL lower than 60% should urge VF studies in SCA3/MJD.