The lower esophagus is one of the extra central nervous organs that share Lewy bodies, which are frequently found in Auerbach’s plexus. Pathological abnormalities may induce variable degrees of functional disorders in the lower esophagus.
Finally, we performed multiple logistic regression analysis of PD with or without GERD. In the analysis, we used “1” to represent PD with GERD, males, and patients with the wearing-off phenomenon and “0” to represent PD without GERD, females, and patients without the wearing-off phenomenon. The other parameters were represented by their original values. The etiology of GERD still remains unclear; however, pathological research has provided some suggestive findings regarding the alimentary system. Lewy bodies in the extra central nervous system have been reported in Auerbach’s and Meissner’s plexuses by systemic pathological examination .
The results of the analysis comparing between PD with and without GERD suggested that GERD was clinically characterized by subjective heartburn and was more common in the advanced stage presenting with the wearing-off phenomenon. The analysis also suggested that GERD could cause deterioration of patients’ daily living activities and quality of life and that GERD was associated with the presence of other nonmotor symptoms. Furthermore, daily living activity and nonmotor symptoms can be independent relating factors of GERD in PD. These results suggest that GERD is a frequent nonmotor problem and a deteriorating factor of daily living activity in PD patients.
Nonmotor symptoms are troublesome for PD patients and physicians because conventional dopaminergic therapy does not always work efficiently in the management of these symptoms. Therefore, physicians should be alert for treatable symptoms. The diagnosis of GERD is commonly based on the history or findings from upper gastrointestinal endoscopy. As a therapeutic diagnostic method, 24 h esophageal pH monitoring combined with the PPI test  is also used. Because clinical history-based diagnosis is the simplest and quickest, demanding no additional workload of the patients, it is suitable for clinical practice.
Increased attention should be given to detect GERD in PD. Gastrointestinal dysfunction is one of the most common nonmotor features of Parkinson’s disease (PD), from the original description by James Parkinson. Variable abnormalities from the mouth through the rectum are already known .
In PD patients, disease duration and severity, quality of life, and nonmotor symptoms were also examined and then the clinical features of GERD were analyzed. A total of 102 patients and 49 controls were enrolled and 21 patients and 4 controls had heartburn, significantly frequent in PD. The prevalence rate of GERD was 26.5% in PD and the odds ratio was 4.05. Heartburn, bent forward flexion, and wearing-off phenomenon were frequent, and scores of UPDRS, total and part II, PD questionnaire-39, and nonmotor symptom scale were significantly higher in PD patients with GERD than without GERD. Multiple logistic regression analysis revealed statistical significance in UPDRS part II and nonmotor symptom scale.
Symptoms of autonomic dysfunction can impact more on quality of life than motor symptoms. Appropriate symptom-oriented diagnosis and symptomatic treatment as part of an interdisciplinary approach can greatly benefit the patient.
pylori can improve these annoying problems in H. pylori-infected PD patients. However, it is unpredictable whether H. pylori eradication is helpful for improving symptoms of GERD in PD patients because the effect of eradication is still controversial in patients with GERD [30-32].
In clinical practice, disappearance of these symptoms following treatment with proton pump inhibitors (PPIs) allows general physicians to reasonably conclude that the patient had acid-related dyspepsia . Dyspepsia is usually defined as upper abdominal pain or retrosternal pain, discomfort, heartburn, nausea, vomiting, or other symptoms considered to arise from the upper alimentary tract. When these symptoms cause deterioration of patients’ daily life quality, PPIs are generally used for treatment because they are more effective than histamine H2 receptor antagonists for reflux-like (heartburn) or ulcer-like (episodic epigastric pain) dyspepsia.
Dopaminergic agents induce gastrointestinal problems by stimulating the peripheral dopaminergic receptors, which are mainly induced as nausea. A clinical review that has described adverse effects of dopaminergic agonists has addressed nausea as a popular adverse effect in the early stage of PD patients, whereas GERD or gastroesophageal influx has not been mentioned . Although nausea is a common clinical symptom of GERD, there is no evidence that nausea leads to GERD.
As shown in the present results, there were no differences in the use of dopaminergic agents expressed as the levodopa equivalent daily dose between PD with GERD and without GERD, which indicates that dopaminergic agents are not directly linked to the development of GERD. There are research data indicating the relationship between spinal kyphosis associated with osteoporosis and GERD in elderly people [16-18]. Postural abnormalities of the trunk are also frequent in PD patients . The bent forward postural abnormality, known as camptocormia, is one such trunk abnormality that occurs in PD patients .