Abstract
A 44-year-old woman presented with a 10-day history of severe, left-sided throbbing headache associated with photophobia, phonophobia, nausea and vomiting, and which worsened with movement. Although she had a history of infrequent episodic migraine since adolescence, she considered this attack to be different from earlier episodes because the pain was very severe and accompanied by eyelid ptosis. She had been seen previously in the emergency room and was treated with triptans without benefit. Neurological exam showed an incomplete left Horner’s syndrome with ptosis and miosis. A brain magnetic resonance imaging (MRI) scan revealed bilateral internal carotid artery dissection with occlusion on the symptomatic side (Figure 1).
(a) Axial MRI, T1-weighted fat-saturated image, showing mural hematomas of the right and left (arrows) internal carotid arteries at the level of their entry into the carotid canal. (b) Magnetic resonance angiography showed a stenosis of the right internal carotid artery (arrowheads in line) and the occlusion of the left internal carotid artery (arrowhead).
Carotid dissection usually causes hemicranial pain with Horner’s syndrome (1), but may be asymptomatic, as seen in this case, with a clinically silent dissection in the other carotid artery. Migraine is associated with a two-fold increased risk of cervical artery dissection (2). MRI is the method of choice for diagnosis because it can show the mural hematoma of the dissected vessel (3).