Horner's syndrome is a combination of symptoms that arises when a group of nerves known as the sympathetic trunk is damaged. The signs and symptoms occur on the same side as the lesion of the sympathetic trunk. It is characterized bymiosis (a constricted pupil), ptosis (a weak, droopy eyelid), apparent anhidrosis (decreased sweating), with or withoutenophthalmos (inset eyeball).
The nerves of the sympathetic trunk arise from the spinal cord in the chest, and from there ascend to the neck and face. The nerves are part of the sympathetic nervous system, a part of the autonomic (or involuntary) nervous system. Once the syndrome has been recognized, medical imaging and response to particular eye drops may be required to identify the location of the problem and the underlying cause.
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Goel s, burkat cn. Unusual case of persistent horner's syndrome following epidural anaesthesia and caesarean section. Indian j ophthalmol [serial online] 2011 [cited 2016 dec 1];59:389-91. Available from: http://www.ijo.in/text.asp?2011/59/5/389/83620
https://www.hindawi.com/journals/criot/2015/570520/ cuneyt kucur, isa ozbay, fatih oghan, nadir yildirim, zuhal zeybek sivas, and sibel canbaz kabay, “a rare complication of radiofrequency tonsil ablation: horner syndrome,” case reports in otolaryngology, vol. 2015, article id 570520, 3 pages, 2015. Doi:10.1155/2015/570520
Mirzai h, baser ef. Congenital horner's syndrome and the usefulness of the apraclonidine test in its diagnosis. Indian j ophthalmol [serial online] 2006 [cited 2016 dec 1];54:197-9. Available from: http://www.ijo.in/text.asp?2006/54/3/197/27073