Recent evidence suggests that the vagus nerve and autonomic dysfunction play an important role in the pathogenesis of Parkinson’s disease. Using heart rate variability analysis, the autonomic modulation of cardiac activity can be investigated. This meta-analysis aims to assess if analysis of heart rate variability may indicate decreased parasympathetic tone in patients with Parkinson’s disease. The MEDLINE, EMBASE and Cochrane Central databases were searched on 31 December 2020. Studies were included if they: (1) were published in English, (2) analyzed idiopathic Parkinson’s disease and healthy adult controls, and (3) reported at least one frequency- or time-domain heart rate variability analysis parameter, which represents parasympathetic regulation. We included 47 studies with 2772 subjects. Random-effects meta-analyses revealed significantly decreased effect sizes in Parkinson patients for the high-frequency spectral component (HFms2) and the short-term measurement of the root mean square of successive normal-to-normal interval differences (RMSSD). However, heterogeneity was high, and there was evidence for publication bias regarding HFms2. There is some evidence that a more advanced disease leads to an impaired parasympathetic regulation. In conclusion, short-term measurement of RMSSD is a reliable parameter to assess parasympathetically impaired cardiac modulation in Parkinson patients. The measurement should be performed with a predefined respiratory rate.

Parkinson´s disease multimodal complex treatment (PD-MCT) is a multidisciplinary inpatient treatment option increasingly applied in Germany. However, data on its effectiveness are rare. Data were collected at the Department of Neurology of the University Hospital Jena, Germany. In 2019, 159 patients were admitted to our neurology ward for PD-MCT. Patients were followed for up to 12 months, and their data were retrospectively analyzed to assess the short- and long-term treatment effects. The treatment led to an improvement in motor function assessed by Movement Disorder Society sponsored revision of the unified Parkinson´s disease rating scale part III (MDS-UPDRS III) and motor performance (Tinetti test). Improvement of MDS-UPDRS III was associated with lower age, higher MDS-UPDRS III at admission, and less depression (assessed by Hospital Anxiety and Depression Scale and Beck-Depression Inventory II). One month after the hospital stay, 36.8% of the patients reported feeling better, while 32.6% reported feeling worse. If the patients were not depressed, they were more likely to have reported feeling better. PD-MCT is an effective inpatient treatment option. However, to improve patients’ satisfaction, screening and treatment for depression is essential. The effectiveness of different treatment durations has to be elucidated in further studies.

The enteric nervous system is involved in the pathology of Parkinson´s disease and patients frequently have symptoms related to delayed gastric emptying. However, the pathophysiology of gastric dysmotility is yet not well understood. The objective of this study was to assess interdigestive gastric motility in Parkinson´s disease. Using an electromagnetic capsule system, the dominant gastric contraction frequency (primary outcome measure) and the gastric transit time were assessed in 16 patients with Parkinson´s disease and 15 young healthy controls after a fasting period of 8 h. Motor and non-motor symptoms were assessed using the Movement Disorder Society Unified Parkinson´s Disease Rating Scale III (MDS-UPDRS III), the Non-Motor Symptoms Questionnaire (NMS-Quest), and Hoehn & Yahr staging. The Gastroparesis Cardinal Symptom Index was used to record symptoms related to delayed gastric emptying. In healthy controls and patients with Parkinson's disease, the dominant contraction frequency was 3.0 cpm indicating normal function of interstitial cells of Cajal. In patients with Parkinson's disease, the gastric transit time was longer than in younger controls (56 vs. 21 min). The dominant contraction frequency and gastric transit time did not correlate with age, disease duration, Hoehn & Yahr stage, levodopa equivalent daily dose, MDS-UPDRS III, NMS-Quest, and Gastroparesis Cardinal Symptom Index. Changes of gastric motility in Parkinson´s disease are not caused by functional deficits of the gastric pacemaker cells, the interstitial cells of Cajal. Therefore, gastroparesis in Parkinson's disease can be attributed to disturbances in neurohumoral signals via the vagus nerve and myenteric plexus.

We present a case of a 26-year-old female patient with bloating, postprandial nausea and recurrent vomiting after solid food intake. A gastric emptying scintigraphy showed a delayed gastric emptying, defining gastroparesis. Because of her past medical history of short stature and pulmonary stenosis, we initiated genetic counseling where the diagnosis of Noonan syndrome was made. Dietary therapy and medication with domperidone quickly led to relief of the discomfort due to gastroparesis. However, prokinetics are not indicated for long-term therapy, as cardiac arrhythmia may occur. A risk-benefit assessment should be done. There are several novel approaches which need to be further investigated.