Neurogenic orthostatic hypotension of Parkinson's disease: what exploration for what treatment?

The aim of this short review is to illustrate, using orthostatic hypotension as an example, the clinical problems related to autonomic features in Parkinson's disease. Orthostatic hypotension is frequently encountered in Parkinson's disease and its diagnosis remains manometric (a fall of at least 20 and/or 10 mmHg in standing blood pressure). It is often associated with supine hypertension to be taken into account before prescribing. To distinguish between the role of disease and of drugs (not only antiparkinsonian drugs), a simple clinical test of autonomic nervous system activity (deep breathing test and standing test with measurement of 30/15 ratio) can be used. When diagnosis with multisystem atrophy is discussed, cardiac [¹²³I]-metaiodobenzylguanidine (MIBG) scintigraphy is of value showing in Parkinson's disease a decreased uptake of the radiopharmaceutical indicating postganglionic sympathetic denervation. Concerning treatment, nonpharmacological methods have to be systematically used since no drug has been specifically evaluated for the treatment of orthostatic hypotension of Parkinson's disease.