Adrenergic innervation in autonomic failure

In 10 patients with chronic autonomic failure, the sympathetic perivascular nerve plexuses from quadriceps muscle biopsies were studied by catecholamine fluorescence and electronmicroscopy. There was almost complete absence of catecholamine fluorescence and fewer than normal numbers of small granular (noradrenergic) vesicles in all nerves studied. The most marked depletion of noradrenergic vesicles was seen in two of the patients with pure autonomic failure, but more studies are needed for a full quantitative comparison of pure autonomic failure and autonomic failure with multiple system atrophy (Shy-Drager syndrome).