Concurrent Horner's and Harlequin syndromes

Harlequin sign concomitant with Horner syndrome after anterior cervical discectomy: a case of intrusion into the cervical sympathetic system

“…The occurrence of Harlequin sign and Horner syndrome together is extremely rare. Similar cases with the iatrogenic occurrence of both syndromes after surgery have been described after total thyroidectomy with neck dissection 8 and following the removal of a large cervical lymphatic malformation in a child. 5 In our case, the identified cause of sympathetic disruption was probably a too laterally situated dissection, which allowed the drain to be positioned against the sympathetic trunk and press on it while following the path of least resistance.…”

“…5 Most of the preganglionic vasomotor and sudomotor fibers dedicated to the face emerge at the level of T-2 and T-3, whereas most preganglionic oculosympathetic neurons originate at T-1. 5,8,14 Preganglionic FIG. 3.…”

A study of the efficacy of stellate ganglion blocks in complex regional pain syndromes of the upper body

“…These suggest that bilateral sympathetic blockade occurs commonly, ranging from functional changes (such as increased hand warming and facial skin blood flow) without gross anatomic changes (such as HS) to a full spectrum. [ 26 27 28 29 ] In our series, we injected 6 ml LA, with the needle apparently perpendicular to the plane, although slight medial angulation of the needle cannot be ruled out. It is theorized that in this patient, the contralateral HS developed due to blockade of contralateral cervical and bilateral thoracic sympathetic chain.…”

Harlequin syndrome as a complication of epidural anaesthesia in an infant: Do adjunct medications play a role?

“…The pathophysiology of Harlequin syndrome is thought to arise from disruption of T2-T3 sympathetic vasodilator and sudomotor facial innervation [ Figure 2 ]. [ 6 ] The distinguishing clinical feature of unilateral facial flushing is thought to arise from sympathetic dysfunction of thermoregulatory vasodilation contralateral to the disrupted sympathetic chain. [ 5 ] The neurologically disrupted side exhibits pallor and anhidrosis while the intact side appears flushed which is thought to be an exaggerated release phenomenon as compensation for loss of sweating and flushing on the contralateral side.…”