Unusual case of contralateral Horner's syndrome following stellate-ganglion block: a case report and review of the literature.

Stellate-ganglion block (SGB) is a commonly performed procedure for the treatment of numerous conditions, including upper-extremity complex regional pain syndromes and arterial insufficiency. The appropriate response to SGB includes ipsilateral Horner's syndrome and temperature elevation of affected extremity. Contralateral and bilateral Horner's syndrome following SGB are rarely seen, with only six prior cases reported. We describe a case of a 47-year-old female with right-hand pain secondary to Raynaud's phenomenon who underwent SGB with subsequent contralateral Horner's syndrome and review the literature of this rare phenomenon.