Dynamic Internal Carotid Artery Dissection Demonstrated by Carotid Duplex Ultrasound

Abstract

Background Carotid artery dissection is an important cause of stroke in young adults. Because warning signs usually precede stroke, the timely diagnosis of carotid dissection can have a significant clinical impact. We present a case of spontaneous carotid artery dissection with dynamic findings on duplex ultrasound examination. Case Report A 47-year-old man presented with acute neurologic symptoms. Carotid duplex ultrasound demonstrated a high resistive waveform in the right internal carotid artery (RICA) with absent end-diastolic flow (peak-systolic velocity [PSV] = 49 cm/sec, end-diastolic velocity = 0 cm/sec), a narrowing of the lumen in the distal RICA with low velocity flow (PSV = 10 cm/sec), and eventual loss of flow. The right common carotid artery demonstrated a high resistive waveform. The use of magnetic resonance angiography confirmed the presence of distal RICA dissection. The patient was treated with antiplatelet therapy and had marked clinical improvement within 48 hours. A duplex ultrasound study performed 24 hours after the first study demonstrated dramatic restoration of the diastolic flow in the RICA (PSV = 97 cm/sec, EDV = 44 cm/sec) with normalization of the Doppler waveforms. Repeat magnetic resonance angiography demonstrated near complete resolution of the RICA dissection, correlating with the ultrasound findings. Conclusion Our case demonstrates the potentially dynamic nature of carotid artery dissection and the utility of duplex ultrasound as an invaluable tool in the early diagnosis and management of this disorder. In addition, the case demonstrates the importance of carotid Doppler waveform clues as indirect evidence of more distal cerebrovascular disease that warrants further investigation.