New insights from a Malaysian real-world deep brain stimulation cohort

BackgroundThe availability of deep brain stimulation (DBS), a highly efficacious treatment for several movement disorders, remains low in developing countries, with scarce data available on utilization and outcomes.ObjectiveWe characterized the DBS cohort and outcomes at a Malaysian quaternary medical center.MethodsA retrospective chart review was done on DBS-related surgery at the University of Malaya, including clinico-demographic, genetics, and outcomes data focusing on post-operative medication reduction and complications.Results149 Parkinson's disease (PD) patients underwent DBS targeting the subthalamic nucleus. Six had globus pallidus internus DBS (primarily for dystonia). Only 16.1% of patients were government-funded. Of the 133 PD patients operated in the past decade (2013-2022), 25 (18.8%) had disease duration <5 years. At 6-12 months post-DBS, median levodopa-equivalent daily dose (LEDD) reduction was 440.5 [418.9] mg/day, corresponding to a reduction of ≥50% and ≥30% in 42.2% and 69.8% of patients, respectively. LEDD reductions were larger in the early-onset and short-duration subgroups. Three patients (1.9% of 155) had symptomatic intracranial hemorrhage, resulting in stroke in two. Pathogenic monogenic or GBA1 variants were detected in 12/76 (16%) of patients tested, mostly comprising the "severe" GBA1 variant p.L483P (12%).ConclusionsThis is the largest report on DBS from Southeast Asia. The procedures were effective, and complication rates on par with international norms. Our study found a high frequency of GBA1-PD; and included a substantial number of patients with short-duration PD, who had good outcomes. It also highlights regional inequities in access to device-aided therapy.