Characterizing motor and non-motor aspects of early-morning off periods in Parkinson's disease: an international multicenter study

Introduction: The characteristic off periods that develop over time in subjects with Parkinson's disease (PD) on chronic levodopa therapy are usually considered to be motor complications but more recently the important contribution of non-motor off and non-motor fluctuations has also been acknowledged. Early-morning off (EMO) periods in PD patients are known to be a cause of significant disability, in addition to having a negative impact on quality of life. Yet EMOs are poorly defined, particularly in relation to non-motor symptoms (NMS).

Methods: This European, multicentre, observational study was undertaken to characterize the range and patterns of NMS that occur during EMO periods in a consecutive series of PD patients.

Results: The results demonstrate that EMO periods are common and occur in 59.7% of subjects across all disease stages in line with other reports. However, importantly, in 88.0% of those, EMOs were found to be associated with NMS. The predominant NMS associated with EMO were urinary urgency, anxiety, dribbling of saliva, pain, low mood, limb paresthesia and dizziness. The patterns of dopaminergic treatment being taken by patients in this study suggested that a prolonged-release or continuous drug delivery strategy can alleviate some NMS associated with EMO.

Conclusions: In light of these findings it is suggested that greater awareness, recognition and appropriate treatment of EMO and NMS could improve the overall 24-h management of PD. An EMO-specific scale/questionnaire which captures both motor and NMS associated with EMO over the off time period is warranted.