Evaluation of cerebral vasomotor reactivity in Parkinson's disease: Is there any association with orthostatic hypotension?

Objective: Our aim was to look for a probable relationship between cerebral vasomotor reactivity (VMR) and orthostatic hypotension (OH) in Parkinson's disease (PD). Materials and methods: This study was conducted on 44 patients with PD. Assessment of cerebral VMR was performed by means of transcranial Doppler (TCD) of middle cerebral artery (MCA) before and after a vasodilatory stimulus, carbon dioxide test. Moreover, orthostatic hypotension was evaluated. Results: OH was presented in 12 (27.3%) Parkinson's patients. The average resting blood flow velocity (BFV) in the MCA was 30.20 (SD = 9.58) cm s(-1) which significantly increased to 46.25 (SD = 16.23)cm s(-1) after carbon dioxide test (P < 0.001). Impaired VMR was observed in 15 (34.1%) of the subjects, while it was not associated with the presence of OH (P = 0.770). Conclusion: Evaluation of VMR in patients affected by PD, could assist in early diagnosis of cerebral autonomic dysfunction and prevent its serious consequences prior and more valid to OH. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.