PURPOSE: Post-COVID-19 syndrome is a poorly understood aspect of the current pandemic, with clinical features that overlap with symptoms of autonomic/small fiber dysfunction . An early systematic analysis of autonomic dysfunction following COVID-19 is lacking and may provide initial insights into the spectrum of this condition .
METHODS: We conducted a retrospective review of all patients with confirmed history of COVID-19 infection referred for autonomic testing for symptoms concerning for para-/postinfectious autonomic dysfunction at Mayo Clinic Rochester or Jacksonville between March 2020 and January 2021 .
RESULTS: We identified 27 patients fulfilling the search criteria . Symptoms developed between 0 and 122 days following the acute infection and included lightheadedness (93 %), orthostatic headache (22 %), syncope (11 %), hyperhidrosis (11 %), and burning pain (11 %). Sudomotor function was abnormal in 36%, cardiovagal function in 27%, and cardiovascular adrenergic function in 7% . The most common clinical scenario was orthostatic symptoms without tachycardia or hypotension (41 %); 22% of patients fulfilled the criteria for postural tachycardia syndrome (POTS), and 11% had borderline findings to support orthostatic intolerance . One patient each was diagnosed with autoimmune autonomic ganglionopathy, inappropriate sinus tachycardia, vasodepressor syncope, cough/vasovagal syncope, exacerbation of preexisting orthostatic hypotension, exacerbation of sensory and autonomic neuropathy, and exacerbation of small fiber neuropathy .
CONCLUSION: Abnormalities on autonomic testing were seen in the majority of patients but were mild in most cases . The most common finding was orthostatic intolerance, often without objective hemodynamic abnormalities on testing . Unmasking/exacerbation of preexisting conditions was seen . The temporal association between infection and autonomic symptoms implies a causal relationship, which however cannot be proven by this study.