Significant Microvascular Abnormalities Are Present in Autonomic Dysfunction: Results of a Prospective Study

Purpose The prevalence and phenotype of capillaroscopic abnormalities in patients with autonomic nervous system dysfunction has not been investigated. Multiorgan involvement in dysautonomia entails abnormal vasoreactivity. We aim to corelate the diagnosis of autonomic dysfunction with certain clinical manifestations that may provide prognostic or diagnostic information using a noninvasive technique: nailfold video capillaroscopy (NVC). Methods Patients with autonomic nervous system dysfunction were recruited from rheumatology and neurology clinic with voluntary NVC procedure from 1/31/24 to 10/1/24 and a comparison with normal controls was done. Additional information recorded includes demographics, diagnosis of type of autonomic dysfunction with autonomic testing including but not limited to reflex screen, sweat test, Valsalva maneuver, nerve fiber density, electromyography (EMG), serology, history of autoimmune disease. NVC was performed on a total of 27 patients. The study was approved by the Mayo Clinic Institutional Review Board. Results Autonomic dysfunction group consisted of small fiber neuropathy (37%), orthostatic hypotension (48%), autonomic neuropathy (30%), limited autonomic neuropathy (7%), POTS (7%) and connective tissue disease (7%) amongst other types. Patient with autonomic dysfunction had statistically significant increased microhemorrhages, dilated capillaries and ramifications compared to controls. There was statistically significant correlation of age with capillary ramifications and BMI with capillary density and dilated capillaries. Conclusion Autonomic dysfunction was associated with statistically significant microvascular abnormalities compared to normal controls with a distinct NVC pattern. There was statistically significant correlation of age and BMI with microvascular abnormalities. We demonstrate diagnostic potential of NVC in autonomic dysfunction and advocate for further study of capillary structure in autonomic dysfunction.