Anxiety and motor fluctuations in Parkinson's disease: A cross-sectional observational study

Background: Some studies have suggested a relationship between anxiety and motor fluctuations in patients with Parkinson's disease (PD). Aim: To describe the nature of the relationship between anxiety symptoms and motor fluctuations and to describe the anxiety symptoms encountered during 'off', 'on' and 'on with dyskinesia' phases. Design and methods: In this cross-sectional study, 250 patients with idiopathic PD, of whom 118 had motor fluctuations, underwent a standardized clinical assessment including the Unified Parkinson's Disease Rating Scale (UPDRS), the DSM IV criteria for major depression and anxiety disorders, the Hamilton Depression Rating Scale (HAMD), and the Hamilton Anxiety Rating Scale (HARS). In addition, patients with motor fluctuations were administered a questionnaire to assess the presence of anxiety symptoms and their relation to motor states. Results: Patients with motor fluctuations suffer from generalized anxiety disorder more often than patients without motor fluctuations. When patients with motor fluctuations have anxiety symptoms, the majority report that these have no temporal relationship with specific motor states. When there was a relationship, symptoms were almost always related to 'off' periods. However, a minority of patients experience anxiety symptoms during 'on' or "on with dyskinesia" periods exclusively. Conclusion: Our findings suggest that the relationship between anxiety and motor fluctuations is more complex than can be explained solely by 'wearing off' phenomena of levodopa. Further studies investigating the temporal dynamics of anxiety and motor fluctuations are needed.