Normal cardiovascular reflex testing in patients with parkin disease.

The objective of this study was to investigate cardiovascular autonomic function in patients with parkin disease. Ten patients with a genetically confirmed diagnosis were compared to 11 healthy controls. Symptoms related to autonomic dysfunction were collected by structured interviews. Cardiovascular autonomic reflex function was evaluated using a standard battery of eight tests. Autonomic tests included the study of sympathetic function through the analysis of blood pressure responses to head-up tilt, standing, isometric hand grip, cold pressor, mental arithmetic, Valsalva maneuver (Valsalva overshoot), and the study of parasympathetic function through the analysis of heart rate responses to deep breathing, hyperventilation, and Valsalva ratio. Seven out of 10 patients reported symptoms involving different aspects of autonomic function, while 5 out of 11 controls reported symptoms related exclusively to orthostatic dizziness and constipation. Symptoms related to bladder dysfunction were the most frequent autonomic abnormality occurring in six patients, followed by orthostatic dizziness and dry mouth (in four patients each). Constipation occurred in three patients, sialorrhea in two, and erectile dysfunction, dry eye, and warm intolerance in one each. Cardiovascular reflex testing revealed no difference between patients and controls in quantitative assessment of both sympathetic and parasympathetic functions, except for diastolic blood pressure after isometric hand grip that did not increase normally in parkin patients compared to controls (P = 0.007). These data show that cardiovascular dysautonomia is not associated to the parkin phenotype, whereas urinary complaints are more frequently reported by parkin patients than by controls. Urinary dysautonomia warrants further investigation in patients with parkin disease.