Harlequin syndrome in a patient with putative autoimmune autonomic ganglionopathy

The author presents a patient with Harlequin and Horner syndromes as part of an autoimmune autonomic ganglionopathy and suggests implication for work-up and management. In general, Harlequin and Horner syndromes are reported to be caused by either a structural lesion of the sympathetic pathway or, when no structural lesion is found, are presumed to be idiopathic. In this paper, a 76 year old man developed a Harlequin and Horner syndromes in the setting of subacute autonomic failure and other systemic features. The patient's symptoms improved with a short course of intravenous methylprednisolone. An autoimmune etiology should be considered in patients with Harlequin syndrome and immunomodulatory treatment could be attempted, especially when there is evidence of a more generalized autoimmune autonomic ganglionopathy.