Vertebrobasilar Insufficiency (VBI): Symptoms, Causes, and Care
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 17, 2026
Quick Answer: What is vertebrobasilar insufficiency (VBI)?
Vertebrobasilar insufficiency (VBI) is reduced or stopped blood flow to the back of the brain, most often caused by atherosclerosis. [1] It affects balance, movement and vision, causing dizziness, vertigo, double vision and slurred speech, and raises the risk of stroke or TIA. [1] Many cases are managed with lifestyle changes and medication [1], and early detection helps prevent serious disability.
What the research says
Posterior circulation stroke is common and driven by familiar risk factors. A review found that posterior circulation ischaemic stroke accounts for 20% to 25% of all ischaemic strokes, that large artery atherosclerosis and embolism are its main causes, and that hypertension is the most common risk factor while diabetes is more specific to this stroke type (Ng, Am J Med Sci, 2022 [2]).
Medication often beats stenting for narrowed arteries here. A review of posterior circulation stroke reported that one-fifth of strokes occur in this territory, and that randomized trial data suggest basilar artery stenosis is better treated with medical therapy than with stenting, which carries a high risk around the procedure. For intracranial vertebral stenosis, medical therapy alone is currently the best option, and the evidence for extracranial stenosis is less clear (Markus and Michel, Int J Stroke, 2022 [3]).
Narrowed vertebral arteries stay high-risk even with medication. A review of vertebral artery interventions noted that patients with symptomatic vertebral artery stenosis treated with medication alone have an annual stroke rate of 10% to 15% and that obstructive vertebrobasilar disease carries a 30% mortality at 2 years if managed medically without added surgical or endovascular treatment. It also noted that trials have not yet been large enough to show conclusively whether stenting is better than medical therapy (Maitas et al., Curr Cardiol Rev, 2023 [4]).
Understanding Vertebrobasilar Insufficiency
Vertebrobasilar insufficiency is a serious vascular condition in which blood flow to the posterior (back) part of the brain is reduced or stops. [1] This area controls basic functions such as balance, movement, and coordination, so when its blood supply is interrupted, those functions can be impaired and a range of neurological symptoms can follow.
Some people have only minor health problems, but VBI is a significant medical concern because it raises the risk of stroke and TIA, commonly called mini-strokes. [1] If it is not managed, it can lead to permanent disability or death.
Symptoms and Warning Signs
VBI symptoms vary with how severely blood flow is restricted. Because the back of the brain controls many functions, symptoms often involve several systems at once, including vision, balance, and motor control.
Symptom category | Specific signs |
Balance and coordination | Vertigo, dizziness, loss of balance, ataxia (loss of coordination), and drop attacks (sudden falls). [1] |
Vision and speech | Double vision, loss of vision, and slurred speech (dysarthria). [1] |
Neurological and physical | Confusion (delirium), difficulty swallowing (dysphagia), nausea and vomiting, and numbness. [1] |
Other signs | Fainting (syncope) and urinary incontinence. [1] |
Seek emergency care for sudden symptoms. Sudden slurred speech, double vision, weakness, or a fall can be signs of a stroke or TIA and need immediate medical attention.
Causes and Risk Factors
The most common cause of VBI is atherosclerosis [1], in which plaque made of cholesterol and calcium builds up inside the arteries. This narrows and hardens the arteries and directly reduces the amount of blood reaching the brain.
Primary Causes
Atherosclerosis: hardening and narrowing of the arteries from plaque buildup. [1]
Artery diseases: penetrating artery disease (blockage of small arteries in the brain) and vertebral artery dissection. [1]
Embolic events: blood clots that travel from the heart or larger arteries and lodge in the arteries at the back of the brain. [1]
Other factors: less commonly, migraines, fibromuscular dysplasia (FMD), and certain blood disorders. [1]
Risk Profiles
People over age 50 are at the highest risk [1], especially those with:
Chronic health issues: diabetes, high blood pressure (hypertension), and high cholesterol or other raised blood fats (hyperlipidemia). [1]
Vascular history: coronary artery disease or peripheral artery disease (PAD). [1]
Heart conditions: atrial fibrillation, blood clotting disorders, or infective endocarditis, which can cause a blocked artery. [1]
Lifestyle and genetics: a history of smoking, obesity, or a family history of VBI. [1]
Demographics: men have twice the risk of women, and Black Americans have a higher risk than other ethnic groups. [1]
Diagnosis and Clinical Testing
Your healthcare provider will ask about your symptoms, review your medical history, and perform a physical exam. [1] Several tests can then show the blood vessels and check your heart function.
Diagnostic Tools
Imaging: CT scans and MRI take pictures of the blood vessels at the back of the brain. [1]
Angiography: X-ray angiography and high-resolution 3D imaging (CTA or MRA) give precise views of the arteries. [1]
Cardiac assessment: an echocardiogram (heart ultrasound) and an EKG or ECG (electrical activity) look for heart-related causes. [1]
Monitoring: a Holter monitor records heart activity for 24 to 48 hours during daily activities. [1]
Blood tests: PT and PTT tests measure how quickly your blood clots. [1]
Management and Treatment Options
Treatment for VBI has several parts. It aims to restore blood flow and to manage the underlying risk factors to prevent future strokes.
Treatment Modalities
Approach | Specific interventions |
Lifestyle changes | Reaching a healthy weight, a heart-healthy diet, regular exercise, and quitting smoking. |
Medication | Drugs to control blood pressure, cholesterol, and diabetes, and to prevent blood clots. [1] |
Surgical procedures | Carotid endarterectomy, angioplasty with stenting, or vertebral artery reconstruction, when symptoms continue despite lifestyle changes and medication. [1] |
Transient (rotational) VBI care | A neck brace or collar, medication, or minimally invasive spine surgery. [1] |
Outlook and Prognosis
The long-term outlook depends on how severe your neurological symptoms are, whether you have already had a stroke, your age, and your other health conditions. [1] Serious cases can lead to disability and death. [1] Most people with mild symptoms can manage them with lifestyle changes and medication, while people with severe symptoms may need rehabilitation for months to years. [1] VBI can come back, with a recurrence rate of 10% to 15%. [1] Treating risk factors early with lifestyle changes and medication can significantly improve the outlook and lower the risk of life-threatening complications.
Prevention
You can lower your risk of VBI by eating a healthy diet, exercising regularly, keeping your cholesterol well managed, quitting smoking, and following your provider's instructions for managing conditions such as high blood pressure and diabetes. [1]
Frequently Asked Questions
1. What is the difference between VBI and a stroke?
VBI is reduced or stopped blood flow to the back of the brain that can lead to a stroke. A stroke happens when blood flow to part of the brain is cut off and brain cells die.
2. Is VBI common?
VBI is quite common in older adults. As many as 25% of people over age 70 may have VBI.
3. Can turning my head cause VBI?
Yes, in a rare form. Transient or rotational VBI, also called bow hunter syndrome or head turning syncope, is triggered by turning or rotating the head.
4. Is VBI more common in men?
Yes. Men have twice the risk of VBI compared with women.
5. Can lifestyle changes really help?
Yes. Reaching a healthy weight, eating a heart-healthy diet, exercising regularly, and quitting smoking are key parts of treatment and can reduce symptoms and stroke risk.
6. What is atherosclerosis?
Atherosclerosis is the hardening and narrowing of arteries caused by a buildup of plaque made of cholesterol and calcium.
7. Do I always need surgery?
No. Surgery is usually reserved for people whose symptoms continue despite lifestyle changes and medication.
8. What are drop attacks?
Drop attacks are sudden episodes of weakness in which a person falls to the ground, typically without losing consciousness.
9. Can migraines cause VBI?
Migraines are a less common but possible cause of vertebrobasilar insufficiency.
10. How long does a Holter monitor test last?
A Holter monitor typically records your heart's electrical activity for 24 to 48 hours while you go about your day.
11. What does an echocardiogram do?
An echocardiogram uses ultrasound to create images of your heart's chambers and valves and to assess its pumping action.
12. Is VBI fatal?
VBI can be if it leads to a major stroke or serious disability. Many people with mild symptoms manage them well with lifestyle changes and medication.
13. What is a TIA?
A transient ischemic attack, or mini-stroke, is a temporary blockage of blood flow. It is a warning sign for a future stroke.
14. Can high cholesterol cause VBI?
Yes. High cholesterol contributes to plaque buildup (atherosclerosis), the most common cause of VBI.
15. When should I see a doctor?
See a healthcare provider promptly for unexplained dizziness, vision changes, or balance problems. Call emergency services right away for sudden slurred speech, double vision, weakness, or a fall, which can signal a stroke.
Related Reading
Trusted External Resources
References
Cleveland Clinic. Vertebrobasilar Insufficiency. Cleveland Clinic. Last updated March 1, 2022. https://my.clevelandclinic.org/health/diseases/22452-vertebrobasilar-insufficiency-vbi
Ng AC. Posterior circulation ischaemic stroke. Am J Med Sci. 2022;363(5):388-398. PMID 35104439. https://doi.org/10.1016/j.amjms.2021.10.027
Markus HS, Michel P. Treatment of posterior circulation stroke: acute management and secondary prevention. Int J Stroke. 2022;17(7):723-732. PMID 35658624. https://doi.org/10.1177/17474930221107500
Maitas O, Bob-Manuel T, Price J, et al. Vertebral artery interventions: a comprehensive updated review. Curr Cardiol Rev. 2023;19(1):e170322202296. PMID 35301953. https://doi.org/10.2174/1573403X18666220317093131
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this article.
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