A 40–year–old male went to his primary medical doctor complaining of headache. He reported a 9/10 dull and achy pain on the right side of his head affecting frontal and temporal regions. He had prior history of headaches but currently his symptoms had persisted for past 10 days without any significant relief with over the counter and prescription analgesics. MR angiography was performed to rule out a cerebral aneurysm due patient’s complaint of persistent headache but demonstrated a long segment dissection of the distal cervical and petrous portions of the right internal carotid artery (Figure 1). Bilateral internal carotid arteries also demonstrated redundancies in the cervical portion forming a loop caudally before entering cranially into the skull. Patient reported history of recent cocaine abuse prior to the start of headache. On admission his BP was 182/126. He was monitored in the Intensive Care Unit (ICU) and intravenous infusion of nicardipine was initiated to control his BP. Infusion of unfractionated heparin was also initiated along with oral warfarin to anticoagulate the patient and to prevent stroke. His headache was relieved as his blood pressure was controlled. He was discharged from the hospital with prescriptions for oral anti–hypertensive medications and warfarin. On discharge he remained compliant with medications and headache free for the next 6 months. CT angiography performed after this time period (Figure 2) showed mild to moderate stenosis of the distal cervical right internal carotid artery with a stable dissection.
Cervical portion of internal carotid artery (ICA) usually has a straight course towards the base of the skull but there are several variations such as kinks, coils and loops of the artery that have been reported. Kinks form a bend which is <= 90 degrees, coils produce a 360 degrees turn and loops form a defect that may occur C or S–shaped. Presence of such anomalies is considered a benign anatomical variant and can pose risks during head and neck surgeries. In this case patient was found to have anomalous ICAs on both sides along with an acute right sided spontaneous dissection. The incidence of spontaneous dissection in lieu of such redundancy is not well established. Another confounding and precipitating factor in this case is patient’s history of cocaine abuse. Acute vascular complications related to cocaine abuse include renal artery dissection, aortic dissection and coronary artery dissection. Cocaine induced carotid dissection has only been reported once previously.
Carotid artery anomalies are usually encountered during routine radiographic evaluations and are considered as normal variants. In this case we have reported a rare complication associated with a carotid artery redundancy precipitated by cocaine abuse.
Figure 1MRA image showing right sided carotid dissection.
Figure 2CTA image showing carotid artery loops and stable right sided dissection.