Vertebrobasilar Artery Insufficiency

Q: I am a 38 year old male and a medical lab technician. I have been having tinnitus in right ear since 2001. Before that I faced problem with double vision. Now my symptoms include vertigo, giddiness, headache and vomiting sensation. I consulted neuro-physician. He checked my BP, which was 140/92, and advised me to get an MRI scan, that reported as follows:

Abnormal T2 hyperintensity noted in the left periventricular region and head of the caudate nucleus, which is hypo on T1 and flair with adjacent hyperintensity on flair. The T2 hyperintensity showing no area of restriction of diffusion on DWI with high ADC values.

Discrete T2 hyperintensity noted in the subcortical bilateral frontal white matter. Rest of the cerebral parenchyma appears normal. The sulci and cisternal spaces are normal. The ventricular system appears normal. Sella and suprasellar region appears normal. Cerebellar fissures are normal. Major intracranial flow voids are preserved. Visualized orbits are unremarkable.

Impression: Chronic infarct in left periventricular and head of left caudate nucleus. Small vessel white matter ischemic changes.

What other test are needed? Would you suggest any changes in treatment? Do I need to consult other departments such as cardiology or ENT. Please give your valuable advice.
-By Venu

Reply:

Brain tissue is very sensitive to hypoxemia (low blood oxygen levels). You can say it is very oxygen hungry, perhaps because it works all the time.

Symptoms of Vertebrobasilar Artery Ischemia

The symptoms you mentioned-

• Double vision
• tinnitus
• vertigo

All these symptoms suggest some problem in the blood supply to the basal areas of your brain. Most probably, the vertebrobasilar arterial system (coming through the back of the neck and entering into the brain tissue from its base) is affected. Either the two arteries- Vertebral and Basilar are narrowed (stenosed) by some pathology or it is occluded (obstructed ) by something there.

Causes of Ischemia

There can be many reasons for this. They include:

• Any trauma to the back of the neck- Leading to direct hit on the arterial system. Damaged arterial system can get occluded.
• More common in young people, a phenomenon called dissection of the arteries occurs. Here the inner lining of the artery peels off and rolls up, and can block the artery, or can be a place where clots form and then break off and embolize downstream.
• Chronic hypertension– Often coupled with atherosclerosis, this condition is common in your age these days. It can lead to gradual narrowing or even occlusion of the affected artery.
• Long history of diabetes, smoking
• Dyslipidemias of any kind
• Hypercoagulable state of blood- Thick blood will have greater tendency for plaque formation, hence occluding the artery.
• Any cardiac problem, generating emboli which later on go and get deposited elsewhere.
• Autoimmune diseases.

Vertebrobasilar artery enters the brain tissue from the base of the skull. After that it divides further into smaller vessels to supply the whole posterior portion of the brain. The anterior part of the brain is supplied by another arterial system called carotid.

Looks like some of the smaller blood vessels coming out of the vertebrobasilar arterial system and penetrating deep into brain tissue are also affected. That is why your MRI shows infarcts in the left periventricular region and head of caudate nucleus.

All these vessels are quite narrow and take sharp turns on their route. These factors make them prone to stenosis and occlusions.

Treatment After Ischemic Events

You are on the right medication. The following objectives need to be met with medicines:

• Blood pressure should be kept in check.
• Some anticoagulant (medicines discouraging the aggregation of platelets any where in blood) coverage is necessary.
• Some anti-inflammatory medicine is required.

We still don’t know the underlying pathology of your disease. Do you have any other problem anywhere else in the body?

I think you can go for a cardiac evaluation. Also, tests for Lupus anticoagulant, anti-cardiolipin antibodies, protein C, protein S, antithrombin III deficiencies can be done. Presence of any of these may hint us about some hypercoagulable state.

CT angiography can be done for exact evaluation of vertebrobasilar vessels. However, many doctors don’t go for it as ionizing radiation and use of nephrotoxic contrast media make it less suitable in young adults because of radiation exposure.

Take Care,

Buddy M.D.