Horner's syndrome 1340251 224902705 2008-07-10T22:39:06Z 78.148.188.226 /* Signs */ {{Infobox_Disease | Name = {{PAGENAME}} | Image = Miosis.jpg | Caption = Left-sided Horner's syndrome | DiseasesDB = 6014 | ICD10 = {{ICD10|G|90|2|g|90}} | ICD9 = {{ICD9|337.9}} | ICDO = | OMIM = 143000 | MedlinePlus = 000708 | eMedicineSubj = med | eMedicineTopic = 1029 | eMedicine_mult = {{eMedicine2|oph|336}} | MeshID = D006732 | }} '''Horner's syndrome''' is a clinical [[syndrome]] caused by damage to the [[sympathetic nervous system]]. It is also known by the names '''Bernard-Horner syndrome''' or '''oculosympathetic palsy'''. ==Signs== Signs found in all patients on affected side of face include [[ptosis (eyelid)|ptosis]] (drooping upper eyelid from loss of sympathetic innervation to the [[Johannes Peter Müller|Müller]] muscle<ref name="isbn0-07-067497-3">{{cite book |author=Adams, Raymond Delacy; Victor, Maurice; Ropper, Allan H. |title=Adam and Victor's principles of neurology |publisher=McGraw-Hill |location=New York |year=2001 |pages= |isbn=0-07-067497-3 |oclc= |doi=}}</ref>), upside-down ptosis (slight elevation of the lower lid), and [[miosis]] (constricted pupil) and [[Pupillary response|dilation]] lag. [[Enophthalmos]] (the impression that the eye is sunk in) and [[anhidrosis]] (decreased [[sweating]]) on the affected side of the face, loss of [[ciliospinal reflex]] and blood shot conjunctiva may occur depending on the site of lesion. In children Horner's syndrome sometimes leads to a difference in eye color between the two eyes ([[heterochromia]]).<ref>{{cite journal | author=Gesundheit B, Greenberg M | title=Medical mystery: brown eye and blue eye--the answer | journal=N Engl J Med | year=2005 | pages=2409–10 | volume=353 | issue=22 | pmid=16319395 | doi=10.1056/NEJM200512013532219}}</ref> This happens because a lack of sympathetic stimulation in childhood interferes with [[melanin]] pigmentation of the [[melanocyte]]s in the superficial stroma of the [[Iris (anatomy)|iris]]. ==History== It is [[eponym|named after]] [[Johann Friedrich Horner]], the [[Switzerland|Swiss]] [[ophthalmology|ophthalmologist]] who first described the syndrome in 1869.<ref>Horner JF. ''Über eine Form von Ptosis.'' Klin Monatsbl Augenheilk 1869;7:193-8.</ref><ref>{{WhoNamedIt|synd|1056}}</ref> Several others had previously described cases, but "Horner's syndrome" is most prevalent. In [[France]] and [[Italy]], [[Claude Bernard]] is also eponymised with the condition ("Claude Bernard-Horner syndrome"). ==Causes== Horner's syndrome is usually acquired but may also be [[congenital]] (inborn) or [[iatrogenic]] (caused by medical treatment). Although most causes are relatively benign, Horner's syndrome may reflect serious pathology in the neck or chest (such as a [[Pancoast tumor]] or thyrocervical venous dilatation) and hence requires workup. * Due to lesion of one side of the cervical sympathetic chain which affects on the same side of the lesion * [[Lateral medullary syndrome]] * [[Cluster headache]] - combination termed Horton's headache<ref>{{cite web | author=Graff JM, Lee AG | title=Horner's Syndrome (due to Cluster Headache): 46 y.o. man presenting with headache and ptosis. | url=http://webeye.ophth.uiowa.edu/eyeforum/cases/case22.htm | work=Ophthalmology Grand Rounds | date=February 21, 2005 | publisher=The University of Iowa | accessdate=2006-09-22}}</ref> * [[Physical trauma|Trauma]] - base of neck, usually blunt trauma, sometimes surgery. * [[Middle ear infection]] * [[Tumors]] - often [[bronchogenic carcinoma]] of the superior fissure ([[Pancoast tumor]]) * [[Aortic aneurysm]], thoracic * [[Neurofibromatosis type 1]] * [[Goitre]] * [[Dissecting aortic aneurysm]] * [[Thyroid carcinoma]] * [[Multiple sclerosis]] * [[Carotid artery dissection]] * [[Klumpke paralysis]] * [[Cavernous sinus thrombosis]] * [[Sympathectomy]] * [[Syringomyelia]] * [[Nerve block]]s, such as cervical plexus block, stellate ganglion or interscalene block == Pathophysiology == Horner's syndrome is due to a deficiency of [[sympathetic]] activity. The site of lesion to the sympathetic outflow is on the [[ipsilateral]] side of the symptoms. The following are examples of conditions that cause the clinical appearance of Horner's syndrome: *''First-order neuron disorder:'' Central lesions that involve the [[hypothalamospinal pathway]] (e.g. transection of the cervical spinal cord). *''Second-order neuron disorder:'' [[Preganglionic]] lesions (e.g. compression of the sympathetic chain by a lung tumor). *''Third-order neuron disorder:'' [[Postganglionic]] lesions at the level of the internal carotid artery (e.g. a tumor in the [[cavernous sinus]]). ==Diagnosis== Three tests are useful in confirming the presence and severity of Horner's syndrome: #Cocaine drop test - [[Cocaine]] blocks the reuptake of [[norepinephrine]] resulting in the [[mydriasis|dilation]] of a normal pupil. Due to the lack of norepinephrine in the synaptic cleft, the pupil will fail to dilate in Horner's syndrome. #[[p-Hydroxyamphetamine|Paredrine]] test:- This test helps to localize the cause of the miosis. If the 3rd order neuron (the last of 3 neurons in the pathway which ultimately discharges norepinephrine into the synaptic cleft) is intact, then the amphetamine causes neurotransmitter vesicle release, thus releasing norepinephrine into the synaptic cleft and resulting in robust mydriasis of the affected pupil. If the lesion itself is of the aforementioned 3rd order neuron, then the amphetamine will have no effect and the pupil remains constricted. There is no pharmacological test to differentiate between a 1st and 2nd order neuron lesion. #Dilation lag test It is important to distinguish the [[ptosis (eyelid)|ptosis]] caused by Horner's syndrome from the ptosis caused by a lesion to the [[oculomotor nerve]]. In the former, the ptosis occurs with a constricted pupil (due to a loss of sympathetics to the eye), whereas in the latter, the ptosis occurs with a dilated pupil (due to a loss of innervation to the [[sphincter pupillae]]). In an actual clinical setting, however, these two different ptoses are fairly easy to distinguish. In addition to the blown pupil in a CNIII ([[oculomotor nerve]]) lesion, this ptosis is much more severe, occasionally occluding the whole eye. The ptosis of Horner's syndrome can be quite mild or barely noticeable. When [[anisocoria]] occurs and the examiner is unsure whether the abnormal pupil is the constricted or dilated one, if a one-sided ptosis is present then the abnormally sized pupil can be presumed to be the one on the side of the ptosis. ==See also== * [[Anisocoria]] ==References== <div class="references-small"> <references/> </div> {{PNS diseases of the nervous system}} [[Category:Neurology]] [[Category:Ophthalmology]] [[Category:Syndromes]] [[de:Horner-Syndrom]] [[es:Síndrome de Claude-Bernard-Horner]] [[fr:Syndrome de Claude Bernard-Horner]] [[it:Sindrome di Horner]] [[nl:Syndroom van Horner]] [[ja:ホルネル症候群]] [[pl:Zespół Hornera]] [[pt:Síndrome de Horner]] [[sv:Horners syndrom]]