Twenty-four-hour blood pressure profile and blood pressure responses to head-up tilt tests in Parkinson's disease and multiple system atrophy.

OBJECTIVE: To investigate the 24 h blood pressure profile in patients with Parkinson's disease with intact autonomic function or with autonomic failure and patients with multiple system atrophy (MSA), and to assess whether these patients exhibit posture-related variations in blood pressure. PATIENTS AND METHODS: We studied 24 patients with Parkinson's disease (11 with autonomic failure) and 13 patients with MSA (all with autonomic failure). Autonomic failure was determined by autonomic tests. An oscillometric recorder was used for ambulatory blood pressure monitoring. Tilt-table tests were performed with a head-up tilt position of 60 degrees.
RESULTS: An alteration in the normal 24 h blood pressure profile was observed in 82% of Parkinson's disease patients with autonomic failure and in 85% of those with multiple system atrophy, but not in the patients with intact autonomic function. Head-up tilt tests revealed a significantly higher supine blood pressure in Parkinson's disease patients with autonomic failure and in those with MSA than in Parkinson's disease patients with intact autonomic function. Tilting resulted in a marked fall in blood pressure in patients with MSA; in Parkinson's disease patients with autonomic failure, the fall was comparatively slighter.
CONCLUSIONS: We conclude that autonomic failure contributes to the alterations in the day-night blood pressure profile that may possibly be ascribed to postural dysregulation of blood pressure. We hypothesize that nocturnal hypertension is a risk factor in the development of additional cerebrovascular disease in patients with Parkinson's disease or MSA who are affected by autonomic failure.