Acute internal carotid artery dissection

Case contributed by Dr Andrew Dixon


Acute left Horner's sydnrome with pain.

Patient Data

Age: 55 years
Gender: Male

CT brain study.

No evidence of sulcal effacement, acute hemorrhage or ischemic changes within the brain. Ventricular pattern is appropriate for age. No acute fractures seen.

The cervical segment of the left internal carotid artery demonstrates a narrowed lumen with a crescent-shaped hyperattenuating focus, favored to be a mural thrombus that extends towards the skull base. This is suspicious for acute left internal carotid artery dissection, especially given the presenting history.

CT angiogram of the brain.

Left internal carotid artery dissection is better appreciated in this study. The left internal carotid artery demonstrates an abnormal vessel contour, with mildly narrowed distal segment surrounded by a non-enhancing crescent-shaped mural thrombus.

The rest of the circle of Willis demonstrates normal enhancement. No other abnormality is seen.

MRI brain.

High T1 and T2 signal crescent sign around the internal carotid artery corresponding to the hyperdensity seen on non-contrast CT. Abnormal vessel contour is again appreciated. These findings are consistent with acute left internal carotid artery dissection. No evidence of cerebral ischemia.

Case Discussion

Internal carotid artery dissection is a common cause of stroke in younger patients and can be spontaneous, traumatic or iatrogenic in etiology. It can present with local pain, headache, ipsilateral Horner's syndrome (as in this case), loss of vision and ischemic stroke symptomatology.

The ICA just prior to the skull base is an important check area on non-contrast CT brain in cases of suspected dissection and Horner's syndrome.

Horner's syndrome can be caused by central, pre-ganglionic and post-ganglionic lesions. Internal carotid artery dissection represents a post-ganglionic lesion and does not classically cause anhydrosis, as opposed to central or pre-ganglionic lesions.

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Case information

rID: 53541
Published: 12th Sep 2017
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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