Pearls and Oy-sters: Carotid dissection with normal arterial lumen

Abstract

OY-STERS• CT angiogram with normal luminal diameter constitutes a challenge for the diagnosis of CAD in the emergency department. The identification of enlargement or thickening along the wall of the internal carotid artery should be sought in patients with suspected CAD. MRI (axial T1 with a fat saturation technique) is the most sensitive test to identify arterial wall changes and confirm the diagnosis.CASE REPORT A 60-year-old man presented to the emergency department complaining he could not whistle and had difficulty moving his tongue. The previous day he had developed sudden onset of left-side headache that remained present until his admission. The day of admission, he noticed that his tongue was deviated to the left side ( figure, A), causing swallowing difficulties. He denied any other neurologic symptoms. Past medical history was remarkable for mild hypertension. He denied high-speed neck manipulation. He acknowledged lifting of heavy boxes in the past 2 weeks. Neurologic examination revealed tongue deviated to the left suggestive of left hypoglossal nerve palsy. The remaining neurologic examination was unremarkable. Unenhanced head CT showed crescentic hyperdensity within the upper cervical internal carotid artery (ICA) at the skull base, suggesting dissection with intramural hematoma (figure, B). CT angiogram showed a cuff of abnormal soft tissue along the periphery of the vessel wall (figure, C) with preservation of luminal diameter. Dissection was confirmed with MRI brain (figure, D) which showed T1 hyperintensity (indicating intramural methemoglobin) within the wall of the internal carotid artery. There was no cerebral infarction. The patient was given aspirin 81 mg once daily. He recovered completely within 2 months.DISCUSSION Cervical artery dissection is a common cause of stroke in young and middle-aged adults.