Orthostatic hypotension following deep brain stimulation in parkinson's disease: a systematic review

Background: Deep brain stimulation (DBS) is a treatment that may be suitable for patients with Parkinson's disease (PD) with severe motor fluctuations and/or dyskinesias despite optimised medical therapy. DBS has been associated with side effects including deterioration in cognition, verbal fluency and mood. Studies assessing the effect of DBS on orthostatic hypotension (OH) have produced variable results. Objectives: The aim is to summarise peer-reviewed studies that have assessed the effect of DBS on systolic or diastolic BP in PD patients. Methods: The databases PubMed, EMBASE, Medline and Scopus were searched using the terms (Deep brain stimulation OR DBS) AND (hypotension OR hypertension OR blood pressure) on 13 April 2017. Results: Fourteen studies fulfilled the inclusion criteria. Ten studies involved subthalamic nucleus (STN) DBS, three studies globus pallidus interna (GPi) DBS and one study involved DBS of the pedunculopontine nuclei and motor thalamus. The majority of the studies found results indicating that DBS in PD does not worsen OH in PD. Conclusions: Small sample sizes and lack of blinding of outcome assessors means this result should be approached cautiously. Future research may further investigate the effect of GPi DBS on OH and should aim to address these methodological issues.