A 38-Year-Old Woman With Anisocoria

Rod Foroozan, MD


September 04, 2015


This patient had acute onset of anisocoria that was greater in the dark, which helped to confirm Horner syndrome. In the absence of other findings that are suggestive of a brainstem stroke, a concerning cause of acute Horner syndrome is dissection of the carotid artery.

In this case, the patient had been using weights in the gym and retrospectively noted the onset of a headache after performing squats with weights. The headache lasted a few hours and then resolved.

Horner syndrome may be the initial manifestation of arterial dissection, and there is a risk for acute stroke in this setting.[1] The incidence of carotid artery dissection has been noted to be 2-3 per 100,000 people.[2] Cervical carotid dissection is a particularly important cause of stroke in younger patients.

Many arterial dissections heal on their own without lasting sequelae.

The management of extracranial carotid dissection is controversial. The majority of patients are treated medically. However, no definitive proof is available to specify which agents should be used. Unfortunately, multiple meta-analyses have shown no distinct benefit of anticoagulation when compared with antiplatelet therapy.[2]

Editor's Recommendations


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.