Wearing off identification using clinical assessments and self-reports in parkinson s disease. A Waking-day monitoring study

Abstract

Background: Parkinson s disease (PD) is characterized by motor fluctuations through the day due to L-dopa treatment. The wearing-off phenomenon is defined as a predictable, clinically relevant motor fluctuation which is routinely identify using clinical scales as well as self-reported questionnaires. Few studies have evaluated accuracy of such tools in identifying wearing-off using a waking-day monitoring study approach of patients motor status. Objectives: to assess diagnostic accuracy of clinical scales as well as self-reported questionnaires compared to an objective proposed tool obtained by a 12-h motor status monitoring in PD patients. Methods: Twenty-two PD patients were enrolled in the study. According to the item 36 of the UPDRS-ME part IV, N=11 patients were classified as fluctuating and N=11 as stable. All patients were clinically evaluated for 12 hours every 2 hours during the day and a Wearing Off Index (WOI) was computed to detect motor fluctuations. Patients also were tested using a self reported questionnaire (WOQ-19) and a 12-hours self diary (NOMO) to identify subjective perceptions of motor and non-motor fluctuations. Results: A WOI score between 2 to 3 was able to detect a wearing-off defined by the UPDRS, with a sensitivity of 90.9% and a specificity of 63.6%. WOQ-19 was less accurate to detect a wearing-off defined by the UPDRS, with a sensitivity and specificity of 90.9 % and 27.3%, respectively. When WOI was used as gold standard, UPDRS-IV item 36 revealed a sensitivity of. 71.4 % and a specificity of 87.5 % to detect the wearing-off, while the WOQ-19 presented a sensitivity of 85.7% and specificity of 25%. According to NOMO diary, fluctuating patients showed a greater percentage of non-motor fluctuations, in particular anxiety and depression (90% and 70%, respectively) even if fluctuating non motor symptoms were also identify in stable patients. Conclusions: our study provided some evidences about accuracy of commonly screening tools to detect wearing-off in clinical practice. A waking day monitoring approach, even if non routinelyapplicable in clinical practice, may be useful to accurately assess changes in motor status through the day due to changes in pharmacological regimen.