The Influence of Serum Uric Acid Level on Non-Motor Symptoms Occurrence and Severity in Patients with Idiopathic Parkinson's Disease and Atypical Parkinsonisms-A Systematic Review

Background and Objectives: A growing number of studies correlated higher levels of serum uric acid (UA) with both: lower risk of Parkinson’s Disease (PD) occurrence and slower progression of the disease. Similar conclusions were made where studies correlated UA with atypical Parkinsonisms (AP) progression. A few researchers have studied the issue of the influence of serum UA on the occurrence of non-motor symptoms (NMS) in PD and AP. Our systematic review is the first review completely dedicated to this matter. Materials and Methods: A comprehensive evaluation of the literature was performed to review the relationship between UA and NMS in PD and AP. The systematic review was conducted according to PRISMA Statement guidelines. The following databases were searched starting in April 2021: MEDLINE via PubMed, Embase, and Scopus. During the research, the following filters were used: >2010, articles in English, concerning humans. The study was not registered and received no external funding. Results: Seven articles meeting all inclusion criteria were included in this study. Collectively, data on 1104 patients were analyzed. A correlation between serum UA concentration and a few NMS types has been provided by the analyzed studies. In four papers, sleep disorders and fatigue were related to UA for both advanced and early PD. Other commonly appearing NMS domains were Attention/memory (4 studies), Depression/anxiety (3 studies), Cardiovascular (3 studies), Gastrointestinal (1 study), Perceptual (1 study), and Miscellaneous (1 study). For AP, no significant correlation between UA and worsening of NMS has been found. Conclusions: Based on the analyzed studies, a correlation between serum UA level and the occurrence and worsening of NMS in PD and APs cannot be definitively determined. Large-scale studies with a more diverse patient population and with more accurate methods of NMS assessment in Parkinsonism are needed.

Comparative analysis of non-motor symptoms in patients with Parkinson's Disease and atypical parkinsonisms

OBJECTIVES

After being diagnosed with idiopathic Parkinson's Disease (IPD) or Atypical Parkinsonism (AP) patients often tend to present non-motor symptoms (NMS). The aim of the study was to explore the differences between occurrence of non-motor symptoms presented by patients with IPD and AP, including sleep, autonomic, psychotic and affective disorders.

MATERIALS AND METHOD

The study included 219 patients (184 with IPD, and 35 with AP) hospitalized between 2016 and 2019 in the Department of Neurology of the Medical University of Silesia. Non-motor symptoms were evaluated using patients' medical chart reviews and NMS questionnaire. The clinical advancement of the disease was assessed using UPDRS part III, and modified Hoehn-Yahr scale (HY).

RESULTS

There were no statistically significant differences between both IPD and AP groups within the parameters of sex, age, HY and UPDRS III OFF scales. Non-motor symptoms were presented significantly often (p = 0.003) in AP patients (n = 32, 91.4 %), then in patients with IPD (n = 122, 66.3 %). Sleep disorders were significantly more prevalent in patients with idiopathic Parkinson's disease (n = 92, 50 %) than in patients with atypical parkinsonism (n = 8, 22.86 %, p = 0.0031). However, autonomic and psychotic disorders didn't show statistically significant differences in both groups.

CONCLUSION

Non-motor symptoms are frequent in both IPD and AP which makes them an integral part of both diseases. Patients with AP are more likely to present non-motor symptoms in general, but rarely they complain of sleep disorders.