The Risk Factors for the Wearing-Off Phenomenon in Parkinson's Disease

Introduction: First-line treatment of Parkinson's disease (PD) includes a dopamine analog, levodopa, administered in combination with carbidopa to increase efficacy. Wearing-off (WO) phenomenon is a frequent complication which is defined as a reoccurrence of motor and non-motor symptoms during levodopa free interval, which has a negative impact on the quality of life of patients. Through this study, we aim to determine risk factors that lead to the manifestation of the WO phenomenon among patients presenting in our out-patient department of a tertiary care hospital in Pakistan. Method: A observational case-control study was conducted from April 2019 to December 2019 in a tertiary care hospital in Pakistan. A total of 101 patients who had PD were included in the study. They were randomized into two groups i.e. patients who had WO phenomenon (59 participants) and patients who did not experience WO (42 participants) phenomena. Patients were evaluated based on a self-administrated questionnaire. A p-value of less than 0.05 was considered significant. Result: WO was significantly higher in those patients who had earlier onset of Parkinson (59 +/- 10 vs. 65 +/- 8; p<0.002) and had the disease for a longer duration (7.9 +/- 5.1 vs. 5.6 +/- 3.1, p<0.002). Other findings included, there was more risk of WO in patients on anti-parkinsonian treatment for longer duration (7.2 +/- 5.1 vs. 3.9 +/- 3.5, p<0.010) and on longer duration on levodopa treatment (6.9 +/- 4.9 vs. 3.1 +/- 2.8, p<0.0001). Conclusion: Our study demonstrated several factors which are responsible for the WO phenomenon. This will aid neurologists to consider these risk factors while prescribing different treatment modalities for the disease to improve efficacy and mitigate WO effect among patients, specifically while advising levodopa.