Gastroparesis and Parkinson's disease: a systematic review.

Some of the gastrointestinal (GI) symptoms commonly experienced by patients with Parkinson's disease (PD) have been attributed to gastroparesis; however, the precise prevalence and relevance of gastric emptying delay in PD is unclear. The definition of gastroparesis varies; currently the most widely accepted definition (from the National Institute of Diabetes and Digestive and Kidney Diseases Gastroparesis Clinical Research Consortium) is the presence of appropriate symptoms (including nausea, retching, vomiting, stomach fullness, and inability to finish a meal) for ≥ 12 weeks, together with delayed gastric emptying on scintigraphy and the absence of any obstructive lesions on upper GI endoscopy. In PD patients, gastroparesis has the potential to affect nutrition and quality of life, as well as the absorption of PD medications, including L-dopa. This reduced absorption of L-dopa has implications for the control of the PD motor symptoms for which it is administered. We performed a systematic review of the literature on gastroparesis in PD with the aim of developing an evidence-based approach to its management. Based on this review, we conclude that while gastric emptying has been reported to be frequently delayed in PD, the existing data do not permit definitive conclusions concerning its true prevalence, relationship to the underlying disease process, relevance to PD management, or the optimal therapy of related GI symptoms. Further study of these important issues is, therefore, required.