Serum noradrenaline response to standing up in patients with Parkinson's disease.

Responses of serum noradrenaline (NA) levels to standing up were determined in patients with Parkinson's disease (PD) examining 15 patients and 13 healthy subjects of similar age in order to obtain information about autonomic failure in PD. Mild symptoms of autonomic dysfunction were found in all the patients. The mean (+/- SD) increment of serum NA levels as a response to standing up of patients was 0.11 +/- 0.29 nmol/l and that of the controls 1.09 +/- 1.15, the percentage rises being 5.4 +/- 12.1 and 38.2 +/- 35.0, respectively. These results indicate that serum NA responses to standing up in patients with PD are significantly diminished describing a sympathetic nervous system deficit in PD.