Predictors of Levo-dopa induced Dyskinesias in Parkinson's Disease

Background: Levodopa has a superior antiparkinsonian effect than dopamine agonists making it the standard of care for patients with Parkinson's disease (PD). During the initial stages, PD patients show a steady response to levodopa. Response fluctuations and levodopa-induced dyskinesias (LID) develop subsequently. The timing and onset of dyskinesias vary among individuals, and there are very few studies identifying the predictors of dyskinesia in India.

Aims: We aimed to study the clinical profile, disability, and predictors of LID in a patient with PD.

Materials and methods: This was a cross-sectional observational study of consecutive patients with PD attending our movement disorder clinic. Patients on levodopa treatment with a minimum follow-up of 6 months were included in the study. All patients were observed before and after administration of levodopa to assess onset, duration of action, and timing of dyskinesias. Dyskinesias were video recorded and classified. Bivariate analysis was performed using Chi-square test or Fisher's exact test and multivariate analysis using binary logistic regression.

Results: This study recruited 110 patients with PD on levodopa therapy. Thirty-one (28.1%) out of 110 had LID. Of these, 25 patients (80.6%) had on-time dyskinesia, 19 patients (61.3%) had off-time dystonia, and 13 patients (41.9%) had diphasic dyskinesia. Majority had only mild-to-moderate dyskinesia. Incapacitating dyskinesias were during off time, primarily affecting the foot. Age, disease duration, disease severity, duration of treatment, and total dose of levodopa were found to be predictors of LID. Multivariate regression analysis showed younger age and longer duration of levodopa treatment to be independent predictors for LID.

Conclusions: LID is fairly common in PD though not severely disabling. Patients with younger age of onset, longer disease duration, and severe disease were more likely to get early LID. We observed the lower prevalence of LID when initiating at lower doses and slow titration of levodopa.