Are patients with GBA–Parkinson disease good candidates for deep brain stimulation? A longitudinal multicentric study on a large Italian cohort

Abstract

BackgroundGBAvariants increase the risk of developing Parkinson disease (PD) and influence its outcome. Deep brain stimulation (DBS) is a recognised therapeutic option for advanced PD. Data on DBS long-term outcome inGBAcarriers are scarce.ObjectiveTo elucidate the impact ofGBAvariants on long-term DBS outcome in a large Italian cohort.MethodsWe retrospectively recruited a multicentric Italian DBS-PD cohort and assessed: (1)GBAprevalence; (2) pre-DBS clinical features; and (3) outcomes of motor, cognitive and other non-motor features up to 5 years post-DBS.ResultsWe included 365 patients with PD, of whom 73 (20%) carriedGBAvariants. 5-year follow-up data were available for 173 PD, including 32 mutated subjects. GBA-PD had an earlier onset and were younger at DBS than non-GBA-PD. They also had shorter disease duration, higher occurrence of dyskinesias and orthostatic hypotension symptoms.At post-DBS, both groups showed marked motor improvement, a significant reduction of fluctuations, dyskinesias and impulsive-compulsive disorders (ICD) and low occurrence of most complications. Only cognitive scores worsened significantly faster in GBA-PD after 3 years. Overt dementia was diagnosed in 11% non-GBA-PD and 25% GBA-PD at 5-year follow-up.ConclusionsEvaluation of long-term impact ofGBAvariants in a large Italian DBS-PD cohort supported the role of DBS surgery as a valid therapeutic strategy in GBA-PD, with long-term benefit on motor performance and ICD. Despite the selective worsening of cognitive scores since 3 years post-DBS, the majority of GBA-PD had not developed dementia at 5-year follow-up.