Exploring the association between pain, demographic and clinical variables in Georgian patients with Parkinson's disease

Pain is a frequent occurrence in Parkinson's disease (PD), with a reported prevalence of >80%. The first ever validated scale to assess pain in PD, the King's PD Pain Scale (KPPS), was developed in 2015. The present study aimed to evaluate the correlation between general demographic (age and sex) and PD‑related characteristics (disease duration, cognitive function, anxiety, depression and disability) and the KPPS score in a patient population with PD. A total of 100 adult patients, aged 45‑86 years, were assessed. The study measured the correlation between PD‑related pain and age, time from disease onset, disability due to impaired mobility, depression severity, anxiety severity, cognitive function and PD severity, followed by multiple regression analysis to determine individual KPPS domain and total scores. Moderate, positive correlations were found between anxiety severity and the KPPS total score, and between disease severity and KPPS Domain 4 score. In addition, weak correlations were present between the following: Anxiety severity and KPPS Domain 1, 3, 4, 5 and 6 scores; age and KPPS Domain 3 score; disability due to impaired mobility and KPPS Domain 4 and KPPS total scores; depression and Domain 1, 4, 5, 7 and KPPS total scores. In multiple regression models, the anxiety score was found to be a predictor of Domain 1, 3, 4, 5 and 6, and KPPS total scores; the disease severity score was a predictor of Domain 4 score; impaired mobility predicted KPPS total score; and depression severity predicted Domain 1 score. Consistent with prior evidence, the correlation and predictive association between anxiety severity and PD‑related pain strongly suggest a cause‑and‑effect association. The association between depression and pain is inconsistently demonstrated and may be subtle and nuanced, although less likely causal. No association was found between KPPS and disease duration, cognitive function or sex. Further research is required regarding the association between clinical and demographical variables and PD‑related pain.