Neurological Disorders: Carotid Artery Dissection

Carotid Artery Dissection is a type of damage to the carotid artery, one of the two prominent arteries that travel upwards in the front front/side area of the neck and supply the brain.

Brain has two sets of blood supply; anterior & posterior, the anterior supply is taken care by carotid arteries and the posterior one by vertebrobasilar circulation.

Dissections of carotid & vertebral arteries are important causes of stroke or mini-stroke in younger people.

During the above mentioned dissection, a tear or rupture occurs in the innermost later of the artery and this causes the entry of blood to the artery wall. This can cause a partial or total blockage to the blood flow in the artery causing stroke or mini stroke. Also due to the damage to inner wall the blood flow may get affected and this may cause development of a clot (thrombus). The thrombus may block the artery locally or one or more pieces from this thrombus may detach (embolus or emboli) and travel further along with the blood and cause a blockage to the flow somewhere distally (embolism). The blood entering the wall of the artery also gets clotted and can cause blockage to the blood flow.

There are myriad causes and are grouped as either;

• Traumatic OR
• Non Traumatic (spontaneous dissection)

Any kind of trauma to the neck may produce dissection although it is more frequent with blunt traumas or traffic accident related injuries to the neck. There are instances where even minor neck injuries have triggered dissection of these arteries.

Under the non traumatic category (spontaneous dissection) following are some important causes;

• Connective tissue diseases like Marfan syndrome, Ehlers Danlos Syndrome etc
• Fibromuscular dysplasias
• Osteogenesis imperfecta
• Polycystic kidney disease etc

The patients will generally present with neck, face, and head area pain due to injury to the carotid artery.

If stroke or mini stroke (TIA) takes place then the following manifestations may be seen (case by case basis);

• Speech difficulties (aphasic conditions)
• Visual (amaurosis fugax which is a transient blindness. Permanent blindness can occur too)
• Unilateral or one sided limb (arm and or leg) weakness and/or numbness/and/or loss of sensation
• Unilateral symptoms of the face as above etc

High degree of suspicion is necessary especially with trivial injuries. The following investigations are generally performed (not all patients require all these tests);

• Ultrasound of carotid artery
• MRA (magnetic resonance angiogram) of carotid artery
• Angiogram with contrast dye of the carotid artery
• CT or preferably MRI of the brain with diffusion sequences if stroke or mini strokes symptoms present
• Any relevant investigations if spontaneous dissection is suspected.

Antiplatelet agents like aspirin or clopidogrel, anticoagulants like warfarin, heparin are the mainstays of treatment. What is the best agent depends upon many factors including how symptomatic the patient etc. Some times surgical or interventional treatment options are necessary too.

A neurologist is frequently involved in the care of these patients with carotid artery dissection.