Parkinson's disease with and without REM sleep behaviour disorder: are there any clinical differences?

Rapid eye movement sleep behaviour disorder (RBD) may serve as a useful indicator to approach Parkinson's disease (PD); however, PD patients do not always exhibit RBD. We wondered whether the presence of RBD would be reflected in the expansion of PD lesions and represent the same PD entity. We examined the clinical differences between PD with and without RBD and studied the frequency of RBD-like symptoms (RBD-s) and clinical differences in 150 PD patients, including 81 patients (54.0%) who satisfied the International Classification of Sleep Disorders, Revised, minimum clinical criteria for RBD. RBD-s preceding the appearance of parkinsonism were found in 44.4% of patients. Statistically, the presence of RBD-s was associated with ages above 65 years, male gender, constipation, dopa-induced dyskinesia and 'sleep attack', with odds ratios of 3.709, 2.469, 2.184, 5.046 and 6.562, respectively. No differences were found between the 2 groups with regard to symptoms at PD onset, disease duration, Hoehn-Yahr stage, hallucination, dementia, wearing-off, orthostatic hypotension, cerebral blood flow and antiparkinsonism drugs. In the early stage, RBD and autonomic system dysfunction are important factors in the progression of PD.