Horner Syndrome

A 47-year-old man presented to theemergency department with adrooping right eye. He also complainedof a constant right-sidedheadache of 1 week's duration; thepain involved the temporal region.Another physician had diagnosednew-onset migraine and prescribedsumatriptan, which failed to alleviatethe pain. The patient had no weakness,vomiting, or double vision.Both his father and his son hadMarfan syndrome.The patient's vital signs werenormal. Mild right-sided ptosis andmiosis--accentuated by dim light--were noted. Cranial nerves wereotherwise intact, and no other neurologicabnormalities were found.The neck was supple without bruits.Breath sounds were normal. Therewas no digital clubbing. A chest radiographand noncontrast CT scanof the brain were normal.Carotid dissection and subarachnoidhemorrhage were consideredin the differential. Analysis ofcerebrospinal fluid from a lumbarpuncture showed no white bloodcells, 3 to 6 red blood cells per microliter,a glucose level of 55 mg/dL,and a protein level of 53 mg/dL.These findings ruled out subarachnoidhemorrhage.During the patient's hospitalstay, a CT scan of the chest was negativefor Pancoast tumor of the lung.An MRI scan/magnetic resonanceangiogram of the brain showed caliberirregularity and slight coursederangement of the high cervical,petrous portion of the right internalcarotid artery. Long-segment atherosclerosiswas considered unlikelybecause there was no other site ofatherosclerotic change. Fibromusculardysplasia was also considered.Carotid dissection was stronglysuspected. An angiogram of thebrain performed a month latershowed a 2.5-cm-long segment ofmild irregularity and focal ulcerationin the middle right internal carotidartery, with no definite evidence of afocal arterial dissection in this area.Horner syndrome--a functionalsympathectomy of the ipsilateraleye--is caused by injury or disruptionof the neural plexus that runsfrom the sympathetic chain, past theapex of the lung, and up the carotidartery to the eye. Ptosis may be subtle.Miosis is more marked in dimlight; it may be difficult to notice inbright light. Potential causes ofHorner syndrome include carotid orvertebral artery dissection, aorticdissection, traumatic carotid injury,deep neck infections, cerebrovascularaccident, cerebellar bleed, clusterheadache, and Pancoast tumorof the lung.Initial symptoms of carotid dissectionusually involve pain that affectsone side of the neck, face, orhead; the pain may start abruptlybut usually the onset is gradual. Pulsatiletinnitus or a bruit is present inabout 25% of affected patients. Earlyneurologic findings may involve thesympathetic plexus (Horner syndromeis present in about 50% of patients),cranial nerve XII, or cerebellarfunction. Eventually, transientischemic attack or thrombotic strokemay occur. The mean time between onset of pain and onset of neurologicsymptoms is 4 days. Carotid dissectionis an important cause ofstroke in young adults and accountsfor up to 25% of cases.¹If carotid dissection is suspected,magnetic resonance angiography(MRA) with fat suppression isthe "gold standard" test. If MRA isnot available, alternative tests includecarotid duplex ultrasonographyand CT angiography (which isalmost as sensitive as MRA).Treatment of suspected carotiddissection involves consultation witha neurologist and a neurosurgeon.In contrast to aortic dissection,thrombosis--not rupture--causescomplications, and treatment withstandard-dose heparin is started insuspicious cases, following a negativehead CT scan. Anticoagulationis usually maintained for 3 months.Surgery is rarely required.This patient almost certainlyhad a carotid dissection related tosubclinical Marfan syndrome. Althoughhis imaging studies werenondiagnostic, they were highlysuggestive of these disorders. Heprobably should have received anticoagulanttherapy for 3 months.Nevertheless, he did well and didnot have a stroke. His Horner syndromeresolved after 3 months, althoughhe complained of occasionalmild right temporal headaches.

(Case and photograph courtesy of D. BradyPregerson, MD. Dr Pregerson is the author of 2medical reference pocket books, Quick Essentialsand Side-Kick, available at www.EDinsight.com.)

References:

REFERENCE:
1.

Chaves C, Estol C, Esnaola MM, et al. Spontaneousintracranial internal carotid artery dissection:report of 10 patients. Arch Neurol. 2002;59:977-981.