Early DEtection of wEaring off in Parkinson disease: the DEEP study

Assessing the frequency of Wearing-Off (WO) in Parkinson's disease (PD) patients, and its impact on Quality of Life (QoL).

Consecutive ambulatory patients, who were on dopaminergic treatment for ≥ 1 year, were included in this multicentre, observational cross-sectional study. In a single visit, WO was diagnosed based on neurologist assessment as well as using the validated Italian version of a patient self-rated 19-question Wearing-Off Questionnaire (WOQ-19); WO was defined for scores ≥ 2. QoL was evaluated by the 8-item Parkinson's Disease Questionnaire (PDQ-8).

617 subjects were included, with a mean anti-Parkinson treatment duration of 6.6 ± 4.6 years, 87.2% were on levodopa treatment. Neurologists identified presence of WO in 351 subjects (56.9%), whereas 415 subjects (67.3%) were identified by the self-administered WOQ-19. In patients with a <2.5 years disease duration, WO was diagnosed in 12 subjects (21.8%) by neurologists and in 23 subjects (41.8%) by the WOQ-19. The most frequent WO symptoms, as identified by WOQ-19, were "slowness of movements" (55.8%) and "reduced dexterity" (48.8%). Younger age, female gender, Unified Parkinson's Disease Rating Scale (UPDRS) part II score and duration of anti-Parkinson treatment were found significantly associated with WO. The number of motor (p < 0.0001) and non-motor (p < 0.0001) WO symptoms correlated with PDQ-8 total score.

WO is common already at the early stages of PD and is underestimated by routine neurological clinical evaluation. The number of WO symptoms, both motor and non motor, increases along with disease duration and has a negative impact on patients QoL.