In a study by Kerry et al. (2008) Cervical Arterial Dysfunction (CAD) is an all-encompassing term used to describe a myriad of pathologies associated with all of the arterial structures found in the cervical spine. Some of the most common CAD pathologies physical therapists may see include:

• local arterial dissections
• atherosclerotic events
• vessel injuries
• non-ischemic events
• ischemic events

The structures within the cervical spine that could be compromised in a patient with CAD include any one of or all of the following:

• Vertebrobasilar arterial system (VBA)
• Internal Carotid arteries (ICA)
• Circle of Willis (CW)

The most common CAD involves the VBA, which is the union of the Vertebral Artery (VA) and the Basilar Artery (BA). These two arteries form the VBA, which supplies blood to the hindbrain.  The VA travels segmentally -by way of the transverse foramina of the cervical segments- to supply blood to the hindbrain (occipital lobe, brainstem, and cerebellum). Excessive rotary motion of the upper cervical segments places stress on the contralateral VA which cuts off blood supply to the hindbrain. In addition, placing this artery under stress while performing manual therapy on the upper cervical spine has the potential to cause CAD, specifically a serious pathology such as VBA dissection. The most serious outcome of a VBA dissection is an ischemic event. It is the responsibility of any physical therapist performing manual therapy of the cervical spine to not place the cervical spine at end range when performing manual therapy. In fact, physical therapists place the cervical spine in minimal rotation when manipulating. Therefore, it can be concluded based on evidence-based research that physical therapists do not cause CAD. The patients that suffer from CAD are actually presenting to physical therapy while it is taking place. Luckily, when one VA is placed under stress, the hindbrain is still able to receive blood thanks to the CW. The CW is an anastomosis (a cross-connection between adjacent channels) of the VBA and ICA. This structure ensures that there is no disturbance of blood flow to the brain. Therefore, the physical therapist is still able to safely apply manual techniques to the upper cervical spine as long as he or she has thoroughly assessed their patient prior to treatment. 

As of now, the literature available does not support the traditional signs and symptoms ruling in/out CAD. Because of this it is up to the therapist to use his or her clinical judgement to determine if it is necessary to refer a patient out for further testing. 

Whenever a patient seeks out physical therapy with a chief complaint of neck pain, the therapist should automatically be triggered to do a thorough subjective screening for possible risk factors of CAD. Asking the patient if they have atherosclerotic risk factors such as diabetes, hypertension, if they smoke, and/or hypercholesterolemia(Kerry 2008) should set off a yellow flag pointing to CAD. According to a study performed by Thomas et al. (2015), patients reporting minor mechanical trauma or neck strain placed a patient at a higher risk for CAD. Minor mechanical trauma being termed by jerky or abrupt head movements, intense or unusual physical effort, or sustained extreme positions of the neck. With strength sports such as Powerlifting, Strongman, and more recently Crossfit, mechanical trauma can be achieved by log pressing maximal weight overhead, performing handstand pushups, or back squatting with maximal weight being misplaced on the shoulders and neck. Mechanical neck trauma is not limited to strength athletes but anyone partaking in a strenuous job or event that places the neck in a compromised position. Such jobs and events include but are not limited to manual laborers, police officers/firefighters, or involvement in a motor vehicle accident. In the same study, a patient reporting an unusual headache or neck pain is the first yellow flag to alert the therapist that a possible CAD could be underway and should be further investigated. However, dizziness and visual disturbances are additional early warning signs the therapist should look for as well.

            In summary, physical therapists must be thorough in their subjective intake of their patients. If a patient presents to therapy with neck pain and a migraine headache, sustained an axial load to their head/neck, smokes, has high blood pressure, has a recent onset of dizziness and has visual field cuts, it is the job of the therapist to refer their patient for further medical screening before performing treatment to their neck.

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Dave Schwartz, SPT

Dr.Brandon Cruz PT,DPT

Board Certified in Orthopedics

Board Certified in Sports

Fellow American Academy Orthopedic Manual Physical Therapy 

Certified Strength & Conditioning Specialist

References: 

Cassidy, J. D., Boyle, E., Côté, P., He, Y., Hogg-Johnson, S., Silver, F. L., & Bondy, S. J. (2009). Risk of             vertebrobasilar stroke and chiropractic care: results of a population-based case-control and                case-crossover study. Journal of manipulative and physiological therapeutics, 32(2), S201-      S208.

Kerry, R., Taylor, A. J., Mitchell, J., McCarthy, C., & Brew, J. (2008). Manual therapy and cervical arterial                  dysfunction, directions for the future: a clinical perspective. Journal of Manual &   Manipulative Therapy, 16(1), 39-48.

Thomas, L. C., Rivett, D. A., Attia, J. R., & Levi, C. (2015). Risk factors and clinical presentation of               cervical arterial dissection: preliminary results of a prospective case-control study. journal               of orthopaedic & sports physical therapy, 45(7), 503-511.