Abstract
Background Autoimmune autonomic ganglionopathy (AAG) is a rare disorder presenting with autonomic dysfunction secondary to alpha-3-ganglionic acetylcholine receptor antibodies (gAChR-Ab). Autonomic dysfunction and neuroimmunological complications following SARS-CoV-2 are reported although de novo pan-dysautonomia due to gAChR-Ab seropositive AAG following SARS-CoV-2 has not been described previously.
Methods We report a case of autonomic failure due to gAChR-Ab seropositive AAG triggered by SARS-CoV-2 infection.
Results A 53-year-old previously healthy male developed subacute autonomic symptoms including, sweating alterations, early satiety, xerostomia, dry eye, constipation and orthostatic hypotension following SARS-CoV-2 infection. These were accompanied by brain fog, gait instability, diplopia, and dysarthria. Examination revealed Adie pupils and mild cerebellar dysfunction.
Autonomic testing demonstrated inappropriate sinus tachycardia and orthostatic hypotension. Symptom management required fludrocortisone, ivabradine and famotidine. Nerve conduction studies, MR brain and CSF studies were unremarkable. Pathological gAChR-Ab were identified in serum by flow cytometric immunomodulation assay (25%, reference ≤18). Serum glutamic acid decarboxylase (GAD) antibody was positive at low titre (15 IU/mL, reference <5). Malignancy was excluded. The patient was diagnosed with AAG, and improved with prednisolone and intravenous immunoglobulin, although with end-of-cycle deterioration. Rituximab achieved sustained improvement in autonomic symptoms, ataxia and brain fog.
Conclusion SARS-CoV-2 infection may precipitate production of gAChR-Ab leading to dysautonomia. AAG is rare but important to identify as an immunotherapy-responsive cause of autonomic symptoms after SARS-CoV-2 infection. Positive serum gAChR-Ab and ancillary autonomic testing confirms the diagnosis. Ataxia is rare in patients with gAChR-Ab and its pathological mechanism is uncertain.
