Longitudinal analysis of impulse control disorders in Parkinson disease.
Level 3 - non-randomized controlled study
Multicenter prospective longitudinal cohort study
PubMed 29925549 · doi:10.1212/WNL.0000000000005816
What was done
A multicenter prospective cohort of 411 patients with Parkinson disease (disease duration ≤5 years at baseline) was evaluated annually for up to 5 years (mean follow-up 3.3 ± 1.7 years). Impulse control disorders (ICDs) were assessed during face-to-face semistructured interviews with movement disorder specialists. Generalized estimating equations and Poisson regression models with robust variance evaluated the time-dependent relationship between ICDs and antiparkinsonian medications, specifically examining dopamine agonist (DA) cumulative exposure, daily dose, and duration.
What was found
Among 411 patients (40.6% women, mean age 62.3 years), 356 (86.6%) took a DA at least once. In 306 patients without ICDs at baseline, the 5-year cumulative incidence of ICDs was 46.1% (95% CI 37.4–55.7), reaching 51.5% (95% CI 41.8–62.1) in DA ever-users versus 12.4% (95% CI 4.8–30.0) in DA never-users. Overall ICD prevalence increased from 19.7% at baseline to 32.8% at 5 years. Ever DA use was associated with ICDs (prevalence ratio 4.23, 95% CI 1.78–10.09). Lifetime average daily dose and duration of treatment were independently associated with ICDs in significant dose-effect relationships. Levodopa was not strongly associated with ICDs, and ICDs progressively resolved after DA discontinuation.
Why it matters
This study provides longitudinal evidence that nearly half of Parkinson disease patients on dopamine agonists develop impulse control disorders within five years, demonstrating a direct dose- and duration-dependent risk that remits after stopping the drug.
Limits
The observational cohort design cannot completely rule out confounding by indication or underlying psychiatric predispositions influencing DA prescribing. Specific subtype breakdown of ICDs and exact numeric risk estimates for specific dose increments are not reported in the abstract. Mean follow-up was 3.3 years rather than the full 5 years across the entire sample.
Cited by
- supports Approximately 1 in 4 Parkinson's disease patients receiving dopamine replacement therapy develop a de novo addictive or impulse control disorder.