Swallowing and deep brain stimulation in Parkinson's disease: A systematic review

Abstract

The purpose of this review is to assess the current state of the literature on the topic of deep brain stimulation (DBS) and its effects on swallowing function in Parkinson’s disease (PD). Pubmed, Cochrane review, and web of science searches were completed on all articles addressing DBS that contained a swallowing outcome measure. Outcome measures included the penetration/aspiration scale, pharyngeal transit time, oropharyngeal residue, drooling, aspiration pneumonia, death, hyolaryngeal excursion, epiglottic inversion, UPDRS scores, and presence of coughing/throat clearing during meals. The search identified 13 studies specifically addressing the effects of DBS on swallowing. Critical assessment of the 13 identified peer-reviewed publications revealed nine studies employing an experimental design, (e.g. “on” vs. “off”, pre- vs. post-DBS) and four case reports. None of the nine experimental studies were found to identify clinically significant improvement or decline in swallowing function with DBS. Despite these findings, several common threads were identified across experimental studies and will be examined in this review. Additionally, available data demonstrate that, although subthalamic nucleus (STN) stimulation has been considered to cause more impairment to swallowing function than globus pallidus internus (GPi) stimulation, there are no experimental studies directly comparing swallowing function in STN vs. GPi. Moreover, there has been no comparison of unilateral vs. bilateral DBS surgery and the coincident effects on swallowing function. This review includes a critical analysis of all experimental studies and discusses methodological issues that should be addressed in future studies.

Dysphagia in a Patient with Cervical Dystonia

“…A published systematic review of literature did not find clinically significant improvement or decline in swallowing function related to DBS in people with Parkinson's disease, and the authors identified a need for further investigation [1]. This case along with another report of DBS-induced fixed epiglottis causing airway obstruction [2] underscores the need for further investigation into the effects of disease pathophysiology, DBS electrode placement, and intensity of stimulation on swallowing function.…”

Decisions about deep brain stimulation therapy in Parkinson’s disease

“…In theory, impairments in speech and swallowing could be induced more frequently by STN DBS, due to its proximity to corticobulbar fibers, but the cited meta-analysis and an additional systematic review did not confirm this association 26,63 . Some features of gait, such as anticipatory postural adjustments and freezing of gait, could improve with surgery, but postural instability and falls are less likely to improve, and might, in fact, worsen after DBS 40 .…”

Implementation of a standardized out-of-hospital management method for Parkinson dysphagia

“…At present, drug treatment and deep brain stimulation therapy are effective for improving PD patients' limb functions, but improvement of swallowing function is not clear and to date remains controversial. [4][5][6][7][8] In recent years, studies have shown that swallowing therapy machine has some effect on vascular Parkinson syndrome with dysphagia.…”