Uric acid: The role in the pathophysiology and the prediction in the diagnosis of Parkinson's disease: A Turkish-based study.

BACKGROUND AND PURPOSE: Oxidative stress has been associated as an essential contributor to the development of neurodegenerative diseases. Recent developments in the field of Parkinson's Disease (PD) pathophysiology have led to a renewed interest in this field. As an antioxidant, uric acid (UA) has arisen as a potential neuroprotectant. Higher concentrations of UA are linked to reducing the risk of the development of the disease and preventing its progression. However, the expositions are unsatisfactory because the outcomes of these reports have not been consistent. This study is set out to assess the association of whether lower UA concentrations increased the PD risk by investigating its relationship with patients' demographic and clinical data, and to determine whether previous studies are compatible with the Turkish-sampled population. Furthermore, we aimed to determine UA's probability of being an early-stage diagnostic marker. METHODS: A total of 305 patients and 100 healthy controls were included. Serum UA levels of patients and controls were compared with clinical features. We classified the patients into three motor subtypes and determined the disease severity by modified Hoehn&Yahr Staging Scale (mH&Y) and Unified Parkinson's Disease Rating Scale (UPDRS). Standardized Mini-Mental State Examination (MMSE-TR) was assessed for cognition. RESULTS: There were not any significant differences of age and sex between patients and controls (p=0.030, p=0.132). The mean UA was 5.06±1.33 mg/dL in patients and 5.46±1.44 in controls, and a statistical significance was detected (p=0.022). The mean MMSE-TR were 24.83±4.35 in patients and 27.09±2.13 in controls, and statictical significance was revealed (p=0.001). The mean duration of the disease was 6.31±4.16 years, mean UPDRS scores were 59.74±22.33, and mH&Y scores were 2.29±0.91. In binary comparisons, patients with tremor-dominant motor subtype had lower UA concentrations than controls (p=0.014). ROC curve analysis revealed UA's cut-off as ≤9.15, the specificity was 99.3, the sensitivity was 10.0, and the area under the curve was 0.576 (p<0.005). Regression analysis revealed age as an independent risk factor on UA values. Oxidative stress might be a factor in the development of PD, and UA may be a possible prospective protecting factor in the clinical course of the disease. However, it does not affect the severity. CONCLUSION: Our results support that lower uric acid concentrations are associated with PD; however, it is not a powerful indicator for predicting PD risk. As we reveal more about UA and its effect in further investigations, its significant role will become well-defined.

Neuropsychiatric Effects of COVID-19 Pandemic on Alzheimer's Disease: A Comparative Study of Total and Partial Lockdown.

Objectives: Coronavirus disease 2019 (COVID-19)-related lockdown may have a negative effect on the neuropsychiatric status of Alzheimer's disease (AD) cases. In this study, it was aimed to find future implications by evaluating the neuropsychiatric conditions of AD cases during total and partial lockdown periods. Methods: It is a prospective, cross-sectional, and multicenter study that includes AD cases which have been followed for at least 1 year by outpatient clinics from different regions of Turkey. Sociodemographic data, comorbidities, mobility, existence of social interactions, clinical dementia rating (CDR) scale, and neuropsychiatric inventory (NPI) for total and partial lockdown were questioned by the caregivers with the help of case files of the patients. Results: A total of 302 AD cases were enrolled to the study (mean age: 78±8 years, mean duration of education: 5.8±9 years). The total comorbidity ratio was found to be 84%, with the most frequent comorbidity being hypertension. The mean NPI score was 22.9±21 in total lockdown and 17.7±15 in partial lockdown, which is statistically significantly different. When lockdown periods were compared with the total scores of NPI scores according to gender, existence of social interactions, mobility, and comorbidities were found higher in the total lockdown than the partial lockdown. When switching from total lockdown to partial lockdown, the presence of comorbidities, mobility, and CDR were found to be factors that had a significant effect on NPI scores. In regression analysis, CDR score was found as the most effective parameter on the neuropsychiatric status of AD cases for both lockdown periods. Conclusion: When lockdown-related restrictions were reduced, the neuropsychological conditions of AD cases were significantly improved. Lockdown rules should be considered with these data in mind.