Clinical and physiological characteristics of autonomic failure with Parkinson's disease

We analyzed the clinical and physiological features of autonomic failure wi th Parkinson's disease (AF-PD) in seven patients and compared them with tho se of autonomic failure with multiple system atrophy (AF-MSA), In AF-PD, pa rkinsonism was more gradually progressive than in AF-MSA, and symptoms were responsive to L-dopa. All seven patients with AF-PD had orthostatic hypote nsion, postprandial hypotension, and constipation, but no urinary retention . Of these, three had hypohidrosis and five had frequent urination; five pa tients had subnormal plasma norepinephrine (NE) concentrations. Supersensit ivity to NE infusion was observed in all patients. Head-up tilting (HUT) te st resulted in no increase of plasma NE concentrations in both groups, but a significant increase of the plasma arginine vasopressin (AVP) concentrati ons in the patients with AF-PD, Urodynamic studies revealed that urinary bl adder function was relatively well preserved in AF-PD in contrast to AF-MSA . In conclusion, there exists some clinical and physiological differences i n autonomic features between AF-PD and AF-MSA, and postganglionic involveme nt predominates in AF-PD.