Assessment of autonomic function in patients with a Parkinsonian syndrome

The integrity of the autonomic nervous system was assessed in 11 Parkinsonian patients with symptoms suggestive of autonomic dysfunction. Three had the additional clinical features of the Shy-Drager variant of idiopathic orthostatic hypotension and were found to have a gross disturbance of vasomotor, sudomotor, pilomotor, and bladder function; assessment indicated that a lesion was present at sympathetic ganglionic level or beyond in two cases, though a more centrally placed lesion may well have been present also, as in the third case. In the remaining eight patients with paralysis agitans no unequivocal functional disturbance was found except in the bladder; nevertheless, the low resting blood pressure and the supersensitivity to intravenously infused L-noradrenaline in the three patients in whom it was tested is taken to imply defective regulation from higher centres, with a consequent reduction in impulse traffic at sympathetic nerve terminals. Such a concept is supported by experimental studies in animals and would account for the low renin and aldosterone secretion rates and reduced noradrenaline formation reported by others in patients with paralysis agitans.