Vertebrobasilar circulatory disorders are conditions in which blood supply to the back of the brain is disrupted.

See also:

• Transient ischemic attack
• Stroke

The vertebrobasilar system is also called the back (posterior) circulation of the brain. Three main blood vessels provide blood flow to the back of the brain:

• One basilar artery
• Two vertebral arteries

The back of the brain contains structures that are crucial for keeping a person alive. For instance, the brainstem controls breathing and swallowing, among other things. Parts of the brain help with vision (occipital lobes) and movement coordination (cerebellus) are also located in the back of the brain.

Many different conditions may cause blood flow in the back part of the brain to be reduced or stopped. The most common cause is a stroke due to hardening of the arteries (atherosclerosis).

Vertebrobasilar vascular disorders may also be caused if a tear ( dissection) in an artery wall leads to the release of a clot that blocks blood flow. Dissection can be caused by clogged arteries, conditions such as fibromuscular dysplasia, or injuries such a car accident. It may even be caused by manipulations of the neck by a chiropractor, or during massage. However, most of the time, no apparent cause of dissection can be identified. When vertebrobasilar disease is present in a younger person, dissection of one of the arteries is often the cause.

Other less common causes of vertebrobasilar vascular disorders include connective tissue diseases and vasculitis.

• Difficulty keeping your balance
• Difficulty swallowing
• Difficulty walking
• Double vision or vision loss
• Headache
• Hearing loss
• Nausea and vomiting
• Neck ache
• Numbness or tingling
• Poor coordination
• Sleepiness or even apparent sleep from which the person can not be awakened
• Slurred speech
• Stroke or transient ischemic attack
• Vertigo (sensation of things spinning around)

Tests depend on the possible underlying cause, but may include:

• CT or MRI of the brain
• Computed tomography angiography (CTA), magnetic resonance angiography (MRA) or ultrasound to look at blood vessels in the brain
• Blood tests, including blood clotting studies
• Echocardiogram
• Electrocardiogram (ECG) and Holter monitor
• Lumbar puncture (spinal tap) -- rarely needed
• X-rays of the arteries ( angiogram)

Sudden onset of vertebrobasilar symptoms is a medical emergency that requires immediate treatment. For treatment information, see:

• Transient ischemic attack
• Stroke

Several possible treatments are available for treating symptoms due to off and on (intermittant) narrowing of the blood vessels. However, there is generally no good surgical treatment for patients who have narrowing of the vertebrobasilar arteries. Blood pressure may be permanently raised to make sure enough blood gets to that part of the brain or blood thinners may be used to make sure additional clots do not form.

The outlook depends in part on the underlying cause. Strokes are potentially life threatening, and require urgent medical care. Age and the person's overall health are taken into consideration when determining one's outlook for recovery. A substantial recovery can be expected in younger patients who have no significant medical problems.

Recovery also depends on the area of the brain that has been affected. The outlook is very poor when the patient is in a coma or cannot move both arms and legs.

Complications of vertebrobasilar circulatory disorders are stroke and its complications. The complications of stroke include:

• Respiratory (breathing) failure (which may require use of a machine to help the patient breathe)
• Lung problems (especially lung infections)
• Heart attack
• Dehydration and swallowing problems (sometimes leading to the placement of tubes in the stomach for artificial feeding)
• Problems with movement or sensation, including paralysis and numbness
• Formation of clots in the legs

Patients may have visual loss in one eye.

Complications caused by medications or surgery may also occur.

Call 911 or your local emergency number, or get to the emergency room if you have any symptoms that may suggest a vertebrobasilar circulatory disorder.

General prevention of strokes caused commonly by atherosclerosis includes cessation of smoking, regular exercise, blood pressure control, healthy diet, and management of diabetes. Prevention of dissection includes avoidance of neck manipulation, and prevention of trauma to the neck.

Lewandowski CA, Rao CPV, Silver B. Transient ischemic attack: definitions and clinical presentations. Annals of Emergency Medicine. 2008 Aug;52(2).

Love BB, Biller J. Neurovascular system. In: Goetz, CG, eds. Textbook of Clinical Neurology. 3rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 22.