An Evaluation of Right-Sided Symptom Onset as a Predictor of Poor Parkinson's Disease Prognosis.

Objective The current study aimed to measure and compare neurological disability in Parkinson's disease (PD) patients with right-sided symptom onset with that in PD patients with left-sided symptom onset, using the measurements taken at their first and last visits, to determine if right-sided symptom onset was predictive of a poor PD prognosis. Methods One hundred and forty-three PD patients were included in the study. The Unified Parkinson's Disease Rating Scale (UPDRS) and the Hoehn and Yahr Scale were used to measure neurological disability in patients at the first and last visits. The scores for the neurological disability of patients at the first and last visits were compared retrospectively relative to disease onset. Results Seventy-six PD patients had right-sided symptom onset (53%), and 67 patients had left-sided symptom onset (47%) (p = < 0.001). The differences between the scores at the first and last visits, measured using the UPDRS and the Hoehn and Yahr Scale, were higher for PD patients with right-sided symptom onset than patients with left-sided symptom onset (p = < 0.001, p = < 0.002, respectively). Similarly, the UPDRS Part II and Part III values, used to evaluate motor function, were higher in PD patients with right-sided symptom onset as compared to those with left-sided symptom onset at the first and last visits (p = < 0.001). Conclusion Right-sided symptom onset was predictive of a poor prognosis in PD patients at follow-up.