Case Report: Deep brain stimulation in SYNJ1-related early-onset parkinsonism

Category	Detail
Condition	Early-Onset Parkinsonism due to SYNJ1 Mutation
Key Mechanisms	Deep brain stimulation (DBS) targeting the subthalamic nucleus (STN) or globus pallidus internus (GPi) to improve motor function and reduce dopaminergic requirements.
Target Population	Patients with early-onset parkinsonism carrying SYNJ1 mutations.
Care Setting	Single-center gene-listed early-onset Parkinson's disease DBS cohort.

DBS showed efficacy in reducing levodopa equivalent daily dose (LEDD) in two patients with SYNJ1-related early-onset parkinsonism.
Case 1: LEDD reduced from 775 to 300 mg/day with improved dyskinesia and sleep.
Case 2: LEDD reduced from 955 to 605 mg/day and UPDRS-III score improved from 51 to 32 at 1.5-year follow-up.
Median LEDD reduction in the contextual cohort was 35.2% after DBS.
Genotype-specific uncertainty remains regarding the efficacy of DBS in SYNJ1 carriers.

Clinical diagnosis of Parkinson's disease supported by genetic testing for SYNJ1 mutations.

Consider DBS as a symptomatic strategy in selected patients with SYNJ1-related early-onset parkinsonism.

Potential for heterogeneous clinical responses to DBS in patients with different SYNJ1 variants.

Patients with genetically confirmed SYNJ1-related early-onset parkinsonism.

DBS may allow for significant reductions in dopaminergic medication requirements.

Clinical Scorecard: Clinical Case Study: Efficacy of Deep Brain Stimulation in Patients with Early-Onset Parkinsonism Due to SYNJ1 Mutation