Dizzy when turning your head? Understanding Bowman's Syndrome (Rotational Vertebral Artery Occlusion Syndrome)

I encountered a male patient in his thirties at the clinic. He had bruised his shoulder and lower neck five years ago, after which a very unique symptom repeatedly appeared: as long as he turned his head to the left, his vision would suddenly go completely black, and he would even come close to losing consciousness; once he turned his head back, the symptoms would quickly resolve.

Over the past few years, he had undergone many rehabilitation sessions and received multiple PRP injections for shoulder and neck discomfort, but the problem was never resolved.

In fact, it wasn't that he hadn't received enough treatment, but rather that the target of the treatment might not have been on the tendons and joints from the very beginning.

The truly critical clue was not "the shoulder had been injured before." What the doctor discovered from the imaging examinations was that the symptoms appeared almost simultaneously with the head-turning movement.
If you are unsure which type of dizziness yours belongs to, please first see 〈Dizzy Only When Turning Your Head, but Fine When Looking Straight?〉

Why Should You Be Especially Careful When Your Vision Goes Black Upon Turning Your Head?

Because this type of symptom points to blood flow, not the musculoskeletal system.

Tendon or joint problems usually cause pain related to the amount of use: the more you move, the more it aches, and it eases with rest. However, vision going black that "appears in a specific posture and resolves upon leaving that posture" is more like a certain structure compressing the arteries supplying blood flow to the brain at a specific angle, causing vision to go black within seconds.

After further examination, an abnormal bony calcified structure was found on the left side of this patient's lower cervical spine at approximately the C6/C7 level. Ultrasound showed that it was very close to the left vertebral artery.

This forces us to highly suspect whether the blood vessel is compressed, pulled, or bent by this structure when the neck is turned to a specific angle, causing a temporary drop in blood flow to the brain.

One of the diagnoses that must be ruled out is called Bow Hunter's Syndrome.

What is Bow Hunter's Syndrome?

The official name is rotational vertebral artery occlusion syndrome (Bow Hunter's syndrome). It is named so because symptoms are often induced when the head is turned to the side—resembling the posture of drawing a bow to aim.

The mechanism is like this: the vertebral arteries run upward along the bony channels on both sides of the cervical spine, supplying blood to the brainstem, cerebellum, and posterior brain. When the head rotates, if the artery is temporarily compressed in a certain segment by bone spurs, abnormal bony structures, fibrous bands, or surrounding tissues, the blood flow in the posterior circulation will be insufficient. Possible symptoms include vision going black or visual abnormalities, dizziness or vertigo, unsteady walking, double vision, and in severe cases, near-fainting or even actual loss of consciousness.

The typical feature can be summarized in one sentence: symptoms are induced by a specific head posture and quickly relieved after returning to the neutral position.

Why Can't Ordinary Examinations Find It?

Because the key to this disease is not "how it looks normally," but "what changes occur in the blood flow at the very moment of turning the head."

Static X-rays, 3D imaging, and ultrasound can provide anatomical clues, such as whether there are bone spurs, calcified structures, and how the blood vessels run. For this patient, imaging found a highly suspicious structure, but this alone cannot directly prove that the blacking out of vision was caused by this bone. Images taken while lying still naturally cannot answer a question that only occurs when turning the head. Each imaging exam has its own range of what it can and cannot see. This concept is fully explained in 〈Why Does It Still Pain Even When the MRI is Normal?〉.

When a Doctor Suspects This Symptom, How Will They Arrange Examinations?

The next step is not to inject more expensive substances, but to perform a dynamic assessment. The sequence is roughly as follows.

First, confirm the vertebral artery blood flow under dynamic conditions, using ultrasound to compare blood flow changes in different head positions. At the same time, rule out other causes that can produce similar symptoms: arrhythmia, abnormal blood pressure, ophthalmological, neurological, and vestibular system problems. Next, compare CTA or MRA in the neutral neck position versus the symptom-inducing posture to see the actual state of the blood vessels at that angle. If necessary, an experienced team will perform dynamic angiography to directly observe whether there is stenosis or occlusion in the blood vessels when turning the head—there are plenty of cases in the literature where static imaging was normal, and occlusion was only found during dynamic examinations.

Excluding items one by one and confirming level by level follows the same logic as all pain with unexplained causes. For the complete process, please see 〈Still in Pain After Half a Year of Rehab, and the Doctor Says No Surgery is Needed?〉.

Taking this patient as an example, the ultrasound blood flow assessment, 3D computed tomography, and X-ray imaging were all completed at Sy-He Clinic, first clearly positioning the location of the suspicious structure and its relationship with the vertebral artery. If dynamic angiography or follow-up treatment is needed in the next stage, we will refer the patient to a medical center along with the organized images and clues so that the medical center team does not have to start from scratch.

If Confirmed, How is It Treated?

It depends on the cause and severity of the compression. In some cases, it is managed through activity adjustment and follow-up. If it is confirmed that a bony structure is compressing the vertebral artery at a specific angle, surgery may be required to remove the compressing structure. There are also some cases in the literature treated with endovascular stenting. Which path is suitable is evaluated by the neurosurgery and neurointervention teams at the medical center.
Such procedures need to be carried out in a medical center. The role of Sy-He Clinic is to complete the diagnosis and then refer the patient.

The reason this symptom cannot be left ignored is that recurrent vertebral artery compression carries a risk of causing a posterior circulation stroke, including cerebellar stroke, in the literature. This is also why this differential diagnosis is worth running through seriously: it usually just looks like "dizziness when turning the head," but it belongs to a small number of neck problems that can actually evolve into a stroke.

Before Confirmation, What Should I, as a Patient, Pay Attention To?

You need to keep three things in mind.

Do not repeatedly turn your head to test it yourself at home. Inducing symptoms means inducing brain ischemia; this is not something to experiment with.

Temporarily avoid high-risk situations: chiropractic neck adjustments, sports or movements with rapid neck twisting, driving, and working at heights. If symptoms occur in these situations, the consequence is not just dizziness; some situations can be dangerous.

Recognize emergency warning signs. If the blacking out of vision persists without fading, or is accompanied by double vision, slurred speech, difficulty swallowing, weakness in limbs, obvious unsteady gait, or severe new-onset head and neck pain, please seek medical attention immediately. These are manifestations of worsening insufficient brain blood flow; do not wait for it to get better on its own.

For the risk zones and dangerous movements of neck massage and adjustments, please see 〈Can a Neck Massage Cause a Stroke? Vertebral Artery Risk Zones, Dangerous Movements, and Medical Warning Signs〉.

What This Case Teaches Us

The first step of treatment is always to make the right diagnosis and find the right cause.

This patient's rehabilitation and injections were not useless, wrong decisions. For example, doing rehabilitation after a shoulder and neck bruise and doing repair injections on the tendons are both reasonable treatment paths. The problem was that a clue not belonging to the musculoskeletal system was hidden in his symptoms, and this clue could only be caught through the pattern of "symptoms synchronizing with posture."

The value of imaging is not just about aiming the needle accurately; more importantly, it is to first confirm whether this problem is indeed one that should be treated with injections. Some symptoms that look like shoulder and neck injuries may actually require dealing with the brain blood flow that disappears at the very moment of turning the head.

Want an Evaluation?

If you have vision blacking out or dizziness that is "induced by a specific posture and relieved upon leaving that posture," you can first describe the pattern of your symptoms (what posture induces it, how long it lasts, how it is relieved) via LINE. The initial evaluations that Sy-He Clinic can perform include a detailed medical history, dynamic ultrasound vertebral artery blood flow assessment, and structural localization using 3D computed tomography and X-rays. If further dynamic angiography or treatment is needed, we will assist with the referral. If the emergency warning signs listed above have already appeared, please seek medical attention directly; do not wait for an outpatient appointment.
Sy-He Clinic is located at 2F-1, No. 40, Sec. 2, Heping E. Rd., Da’an Dist., Taipei City. It operates entirely on an appointment basis, phone (02) 2366-0186.

Author: Dr. Bing-Sheng Lu

Last Updated: August 11, 2026

The case in this article has been de-identified. This article is for general health education information and cannot replace doctor diagnosis and treatment advice; individual diagnosis must still be confirmed by a complete medical history and dynamic vascular examination.

Medical Literature References

1. Choi JW, Qiao Y, Mehta TI, et al. Safety and efficacy of dynamic catheter-directed cerebral digital subtraction angiography for diagnosis of bowhunter syndrome spectrum disorders: a systematic review of the literature. Interventional Neuroradiology. 2024. doi:10.1177/15910199241236820

2. Duan G, Xu J, Shi J, Cao Y. Advances in the Pathogenesis, Diagnosis and Treatment of Bow Hunter's Syndrome: A Comprehensive Review of the Literature. Interventional Neurology. 2016;5(1-2):29-38. doi:10.1159/000444306

3. Vertebral Artery Stenting in a Patient With Bow Hunter's Syndrome. JACC: Case Reports. 2019. doi:10.1016/j.jaccas.2019.05.010