Internal Carotid Artery Dissection and Asymmetrical Facial Flushing
The Harlequin Sign
A 47-year-old woman presented to her primary care physician (PCP) with severe left-sided headache localized in the retrobulbar and temporal region. The PCP suspected migraine and prescribed a nonsteroidal anti-inflammatory drug. But despite analgesic treatment, her headache continued, and she returned to her PCP 2 weeks later. At this visit, the PCP noticed new anisocoria with a miotic pupil on the left. Emergent magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of neck and brain revealed no acute or subacute cerebral lesions but a narrowing and semicircular wall hematoma of the left internal carotid artery (ICA) up the petrous segment (Figure 1). The wall hematoma resulted in almost complete occlusion of the arterial lumen. Hereafter, she was transferred to our stroke center, where we confirmed diagnosis of ICA dissection with incomplete Horner syndrome.
Extracranial and intracranial duplex sonography revealed a resistance flow profile in the dissected ICA indicating distal occlusion. Collateral circulation through the left posterior communicating artery maintained the blood flow in the left anterior and middle cerebral artery. Six days later a repeated ultrasound showed improving blood flow with only local flow accelerations in the distal extracranial portion of the dissected ICA. The patient was treated with aspirin 300 mg daily for 2 weeks followed by a dose reduction to 100 mg daily. During hospitalization, she remained clinically stable and was discharged home after 8 days.