Prevalence and factors related to orthostatic syndromes in recently diagnosed, drug-naïve patients with Parkinson disease.

Orthostatic syndromes were common in the recently diagnosed drug-naïve patients with PD enrolled in the study, but only the prevalence of OI was higher in PD patients than in the non-parkinsonian controls. Unlike motor or functional disability indicators, markers of dopaminergic striatal deficit and gastrointestinal dysfunction were associated with OH and OI.