Subcutaneous Apomorphine Infusion Initiation Is Associated with Impulse Control Disorder Attenuation in Advanced Parkinson's Disease Patients: Insights from the French NS-Park Cohort.

Background: Impulse control disorders (ICD) are common non-motor complications in Parkinson's disease (PD), particularly in patients receiving oral dopamine agonists (DA). Continuous subcutaneous apomorphine infusion (CSAI) is a device-aided therapy for advanced PD, but its effects on ICD remain underexplored in real-world settings.

Objectives: To assess the impact of CSAI initiation on ICD prevalence and severity in a large real-world PD cohort and to compare ICD evolution in CSAI-treated patients versus orally-treated controls.

Methods: We analyzed data from the national prospective observational NS-Park cohort, selecting patients with documented ICD status before and after CSAI initiation. Changes in ICD prevalence and severity based on the MDS-UPDRS sub-item 1.6 were assessed using paired statistical tests, with additional sensitivity analyses based on time-restricted sub-cohorts (considering 60-, 24- and 12-months follow-up). A matched case-control analysis and a propensity score matching were used to compare CSAI-treated patients to orally-treated PD patients.

Results: 149 patients were included in the analysis. Before CSAI initiation, slight and mild/severe ICDs were present in 17% and 5% of the patients, respectively. After CSAI starting, ICD prevalence significantly decreased from 22% to 13%, (P = 0.003). These improvements were consistent across different time windows, despite an overall increase in DA levodopa-equivalent dose, with no associated mood worsening (up to 24-month follow-up). CSAI was associated with longitudinal ICD reduction, contrasting with the stable or worsening ICD trajectory in orally-treated controls, though trajectories were not statistically different.

Conclusions: The presented findings of our real-life cohort suggest that ICD tend to improve following CSAI initiation in patients with PD, likely due to a reduction of oral DA or the effect of continuous dopaminergic stimulation provided by the pump. While this observation is clinically relevant, it should be interpreted with caution given the study's observational design and the limitations inherent to using MDS-UPDRS sub-items for ICD assessment.