Clinical and Healthcare Disparities in Migrant Patients with Parkinson's Disease: A Matched Cohort Study in a Multiethnic European Population.

Background/Objectives: Data on Parkinson's disease in immigrant populations are limited despite increasing migration and population aging in Europe. This study aimed to evaluate differences in clinical presentation and healthcare engagement between immigrant and native patients with Parkinson's disease in a multiethnic European setting. Methods: We conducted a retrospective matched cohort study including immigrant patients with Parkinson's disease followed at our Movement Disorders Unit between 2000 and 2025. Immigrant patients were matched 1:1 with native patients by age, sex, and year of diagnosis. Clinical characteristics, prodromal symptoms, motor severity, and healthcare engagement variables were analyzed. Results: Ninety-eight immigrant patients were matched with 98 native patients. Most immigrants originated from Latin America and North Africa. Native patients showed a higher prevalence of hyposmia than immigrant patients (49.0% vs. 26.5%; p = 0.002). No significant differences were observed in disease duration, pattern of motor symptom onset, motor severity, Hoehn and Yahr stage, MDS-UPDRS scores, or antiparkinsonian treatment during follow-up, although native patients had higher postural tremor scores at baseline. Immigrant patients demonstrated lower healthcare engagement, with higher rates of missed follow-up visits (34.7% vs. 16.3%; p = 0.003) and poorer treatment adherence (24.5% vs. 11.2%; p = 0.016). Conclusions: Immigrant patients with Parkinson's disease showed a lower prevalence of hyposmia and reduced healthcare engagement despite otherwise comparable clinical characteristics, motor severity, and treatment patterns. These findings highlight the importance of considering sociocultural determinants and barriers to healthcare utilization when managing Parkinson's disease in increasingly diverse populations.