Teaching NeuroImages: Harlequin syndrome caused by lesion of sympathetic regulatory neurons

Harlequin Syndrome After Thoracic Paravertebral Block

Harlequin syndrome is characterized by the sudden onset of unilateral facial flushing and sweating, often preceded by exercise, excessive heat, or, rarely, regional anesthesia. Although the exact mechanism remains unclear, it is often referred to as transient or permanent interruption of the sympathetic nervous system. We present a case of Harlequin syndrome without Horner syndrome in a patient with unilateral right-sided facial flushing that started shortly after a left-sided thoracic paravertebral nerve block for a mastectomy. We discuss the interruption of the sympathetic and parasympathetic nervous system and the levels of spinal nerve block associated with a thoracic paravertebral nerve block.

Harlequin Color Change: Neonatal Case Series and Brief Literature Review

First clinical report of Harlequin color change (HCC) phenomenon came in 1952 from Neligan and Strang. Since then, HCC has been described in a fairly broad number of clinical reports involving neonates, infants, children, and adult patients. We here present a small case series of HCC occurring in neonates, pointing out three of the different possible presentations (hemifacial, patchy scattered across the whole body, and hemiscrotal) of this phenomenon. A brief discussion and literature review encompassing epidemiology, clinical features, physiopathology, associated conditions, and differential diagnoses of HCC is then presented. In most cases, HCC represents a benign, idiopathic, and rapidly autoresolutive phenomenon, with no need for treatment. Some drugs (especially anesthetics and prostaglandin E) are thought to enhance HCC expression through their influence on the capillary tone in the peripheral vascular bed; this effect is anyway promptly reversible with drug withdrawal. Only in rare circumstances, HCC may act as a clue for serious central nervous system disorders (e.g., meningitis; hypothalamic, brain stem, or sympathetic nervous system lesions); anyway, in these rare occurrences HCC always represents an epiphenomenon of the disease, never acting as the sole sign of the underlying disorder.

[Dysautonomic syndrome of the face with Harlequin sign and syndrome: Three new cases and a review of the literature]

INTRODUCTION

Harlequin phenomenon is characterized by a strictly unilateral erythrosis of the face with flushing and hyperhydrosis, and controlaterally a pale anhydrotic aspect. This syndrome can occur alone or associated to other dysautonomic phenomena such as Horner syndrome, Adie syndrome or Ross syndrome.

PATIENTS AND METHODS

We report three cases: two patients presented a Harlequin sign, associated with Horner syndrome for one and Ross syndrome for the second. The etiologic investigation was normal, allowing recognizing the idiopathic nature of the disorder. For the third patient, Harlequin syndrome was observed in a neoplastic context due to breast cancer, metastatic dissemination, and bone metastases involving the right side of the T2 body.

DISCUSSION

We reviewed the literature: 108 cases have been described. This syndrome occurred alone in 48 patients and was associated with other dysautonomic syndromes such as Horner syndrome in 38 patients, Holmes Adie syndrome in six, and Ross syndrome in six; both Ross and Holmes Adie syndrome were associated five cases and associations were not reported in five patients. The pathophysiological mechanisms of this autonomic cranial neuropathy, the possible etiologies, and therapeutic management were discussed.

CONCLUSION

Harlequin phenomenon with flushing and unilateral hyperhydrosis is rare, occurring alone or in combination with other autonomic syndromes of the face. Idiopathic in two-thirds of cases, Harlequin phenomenon does not require specific treatment; sympathectomy may be discussed in the severe cases with a significant social impact.