Transcutaneous vagal nerve stimulation improves gastroenteric complaints in Parkinson's disease patients

BACKGROUND: Gastrointestinal dysfunctions are common in Parkinson's disease. Their management is still challenging and new treatment options are needed. OBJECTIVE: To test whether transcutaneous vagal nerve stimulation can improve gastrointestinal dysfunction in patients with Parkinson's disease. METHODS: We performed a randomized double-blind pilot study enrolling patients suffering from Parkinson's disease with gastroenteric complaints. Patients were randomized to use either a sham-device or to stimulate the vagal nerve with an electric device over the course of four weeks with four stimulations per day. Ten patients (aged 69.6 +/- 4.6 years) were randomized for the intervention group, and nine patients (aged 67.2 +/- 6.3 years) used a sham-device. Clinical outcome was evaluated using the Gastrointestinal Symptom Rating Scale whereas gastrointestinal motility was measured with the C-13-octanoic acid breath test. RESULTS: In the treatment group, vagal nerve stimulation improved the Gastrointestinal Symptom Rating Scale comparing before and after stimulation (before, 8.7 +/- 6.09; after 5.67 +/- 3.08; p-value 0.48). This improvement was not observed in the sham group (before, 7.44 +/- 4.85; after, 5.67 +/- 3.08; p-value 0.16). In the C-13-octanoic acid breath test no significant changes were detectable. CONCLUSIONS: Vagal nerve stimulation is well tolerated with no side effects and may be a promising non-invasive therapy option to improve gastroenteric symptoms in Parkinson's disease.