[Utility of the study of the vegetative nervous system in the differential diagnosis between Parkinson's disease and multiple system atrophy]

INTRODUCTION

The aim of this study is to show if the exploration of the autonomic nervous system is useful to improve the specificity of clinical criteria of Parkinson's Disease (PD) and Multiple System Atrophy (MSA).

PATIENTS AND METHODS

20 patients with PD and 13 patients with MSA were studied. After 12 hours in off medication, NE and GH were measured in supine position and NE after 5 minutes standing. Later, GH levels were recorded at 15, 30, 45 and 60 minutes after a dose of 0.005 mg/kg of apomorphine. Finally, analysis of the symptoms of autonomic dysfunction and levodopa test were carried out.

RESULTS

Sympathetic response to postural changes was significantly higher in patients with PD (NE increase in relation to basal: PD: 170.90 +/- 110.08 pg/ml; MSA: 91.33 +/- 73.79 pg/ml; p = 0.029). No differences were found in the response of GH to apomorphine (GH peak at 45 minutes: PD: 2.37 +/- 2.7 ng/ml; MSA: 1.69 +/- 1.90 ng/ml; ns). The symptoms of autonomic dysfunction were more frequently in patients with MSA. The stridor was specific to MSA. Improvement in motor scores in the levodopa test was higher in patients with PD (PD: 39.7 %; MSA: 17.89; p = 0.019).

DISCUSSION

Sympathetic response to postural changes, description of symptoms of autonomic dysfunction, and motor response to levodopa test are useful tools in order to improve specificity of the diagnostic criteria of PD and MSA. The GH test with apomorphine was not useful for a differential diagnosis.