Deep brain stimulation in Early Onset Parkinson's disease

Motor and Non-motor Outcomes of Deep Brain Stimulation across the Genetic Panorama of Parkinson's Disease: A Multi-Scale Meta-Analysis

BACKGROUND

In the era of modern medicine, where high-throughput sequencing techniques are readily available, it is desirable to elucidate the role of genetic background in patients with Parkinson's Disease (PD) undergoing Deep Brain Stimulation (DBS). Genetic stratification of PD patients undergoing DBS may assist in patient selection and prediction of clinical outcomes and complement existing selection procedures such as levodopa challenge testing.

OBJECTIVE

To capture a broad spectrum of motor and non-motor DBS outcomes in genetic PD patients with data from the recently updated literature.

METHODS

A multi-scale meta-analysis with 380 genetic PD cases was conducted using the Cochrane Review Manager, JASP software and R.

RESULTS

This meta-analysis revealed that overall, patients with genetic PD are good candidates for DBS but the outcomes might differ depending on the presence of specific mutations. PRKN carriers benefited the most regarding motor function, daily dose medication and motor complications. However, GBA carriers appeared to be more prone to cognitive decline after subthalamic nucleus DBS accompanied by a low quality of life with variable severity depending on genetic variants and concomitant alterations in other genes. Apart from GBA, cognitive worsening was also observed in SNCA carriers. Pre-operative levodopa responsiveness and a younger age of onset are associated with a favorable motor outcome.

CONCLUSION

A personalized approach with a variant-based risk stratification within the emerging field of surgicogenomics is needed. Integration of polygenic risk scores in clinical-decision making should be encouraged.

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

BACKGROUND

GBA variants 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 in GBA carriers are scarce.

OBJECTIVE

To elucidate the impact of GBA variants on long-term DBS outcome in a large Italian cohort.

METHODS

We retrospectively recruited a multicentric Italian DBS-PD cohort and assessed: (1) GBA prevalence; (2) pre-DBS clinical features; and (3) outcomes of motor, cognitive and other non-motor features up to 5 years post-DBS.

RESULTS

We included 365 patients with PD, of whom 73 (20%) carried GBA variants. 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.

CONCLUSIONS

Evaluation of long-term impact of GBA variants 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.