The demographic characteristics of the study population and their questionnaire scores are detailed in Table 1. Postural instability was reported by 26 patients, whereas swallowing problems were reported by 14 and FOG by 19; 23 patients reported impairment in more than one domain (Fig. 1).
The FES total score correlated positively with SDQ total score (Spearman’s rho = 0.594; P = 0.001), as well as oral (rho = 0.619; P < 0.001) and pharyngeal subscales (rho = 0.563; P = 0.001). In contrast, neither SDQ total (rho = 0.176; P = 0.362) nor subscales showed a correlation with FOG Questionnaire score.
We performed multiple linear regression with total SDQ as the dependent variable using age, gender, disease duration, LEDD, and FES total score as predictive variables. In this model, FES total score was a significant predictor of SDQ score (standardized β = 0.533, P = 0.004), whereas other variables did not reach statistical significance.