Correlation of the severity of autonomic dysfunction to cardiovascular reflexes and to plasma noradrenaline levels in Parkinson's disease.

The present study analyses the relation of both the diminished cardiovascular reflexes and the diminished plasma noradrenaline (NA) response to standing to the severity of the autonomic nervous system (ANS) dysfunction in patients with Parkinson's disease (PD). 47 patients with PD were investigated. A clear correlation was established between the duration and the severity of PD (by the Webster rating scale) and the degree of autonomic dysfunction (ANS disability scale). Similarly, a significant negative correlation was found between the diminished cardiovascular reflexes and the clinical severity of the ANS disturbance. Furthermore, a slight correlation was shown between the clinical severity of ANS dysfunction and plasma NA concentrations in response to a standing-up stimulus.