Subthalamic Nucleus Deep Brain Stimulation in Early-onset Parkinson's Disease: Clinical Outcomes in LRRK2 Mutation...

Subthalamic nucleus deep brain stimulation (STN-DBS) is an established treatment for early-onset Parkinson's disease (EOPD). While the effect of STN-DBS on patients with LRRK2 G2019S mutation has been largely investigated, data specific to EOPD patients with this mutation remain scarce. This study examines the impact of the LRRK2 G2019S mutation on STN-DBS outcomes in EOPD patients in Morocco, a developing country where such treatment is challenging to provide.

A prospective cohort study was conducted at the University Hospital of Ibn Rochd in Casablanca. Genomic DNA was analyzed for the LRRK2 G2019S mutation, and clinical data were collected before and after surgery. Motor outcomes, including dyskinesia, motor fluctuations, and reduction in levodopa equivalent daily dose (LEDD), were assessed one year post-DBS.

Seventeen EOPD patients who underwent STN-DBS were included, with 10(58.8%) being carriers of the LRRK2 G2019S mutation. The mean age of participants was 57.2±8.4 years, with a mean age at onset of 37.9±6.2 years. Motor fluctuations were present in 88.2% of patients, and 94.1% experienced dyskinesia. Following DBS, both mutation carriers and non-carriers demonstrated significant improvements in motor symptoms, with a mean improvement of 61.3% in the unified PD rating scale (UPDRS) III. Dyskinesia and motor fluctuations, as measured by specific UPDRS IV items, improved by 77.1% and 83.8%, respectively, with a mean LEDD reduction of 60.6%. Improvements were comparable between LRRK2 G2019S carriers and non-carriers. All patients were satisfied with the treatment, though one patient had a hardware-related infection.

STN-DBS is effective in managing motor symptoms and reducing medication needs in EOPD patients, regardless of LRRK2 G2019S mutation status.