The vertebral artery test is used to assess blood flow in the vertebral artery to identify potential vertebrobasilar ischaemia, which can lead to transient ischaemic attacks (TIA) or strokes. Controversy exists regarding the test's validity, as several studies have shown inconsistent results, with some indicating a lack of significant blood flow changes during cervical spine rotation. Due to the questionable reliability of the test, caution is advised in its application before cervical spine manipulation.

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THE INTERNATIONAL ACADEMY OF OSTEOPATHY
Luc Peeters, MSc.Ost. @ Grégoire Lason, MSc.Ost.
The Vertebral Artery Test
The vertebral artery test is used to test the vertebral artery blood flow, searching for
symptoms of vertebrobasilar ischaemia.
The test is relevant because it is a major artery in the neck that branches from the
subclavial artery where it arises from the posterosuperior portion of the subclavian
artery.
The vertebral artery ascends thought the foramina of the transverse processes of the
sixth cervical vertebrae. Then, it winds behind the superior articular process of the
atlas and enters the cranium through the foramen magnum where it unites with the
opposite vertebral artery to form the basilar artery.
The vertebral artery can be divided into four divisions:
1. The first division runs posterocranial between the longus colli and the m.
scalenus anterior. The first division is also called the ‘pre-foraminal division’.
2. The second division runs cranial through the foramina in the cervical
transverse processes of the cervical vertebrae C2. The second division is also
called the ‘foraminal division’.
3. The third division is defined as the part that rises from C2. It rises from the
latter foramen on the medial side of the rectus capitis lateralis, and curves
behind the superior articular process of the atlas. Then, it lies in the groove on
the upper surface of the posterior arch of the atlas, and enters the vertebral

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canal by passing beneath the posterior atlantoöccipital membrane.
4. The fourth part pierces the dura mater and inclines medial to the front of the
medulla oblongata.
A reduction of blood flow through the vertebral artery may result in a transient
ischiamic attack (TIA), a critical harbinger of impending stroke.
What is TIA? TIAO is similar to stroke but the symptoms diminish in minutes (less
than 24 Hours).
https://www.youtube.com/watch?v=Q68XVzzFMCY&index=2&list=PL3FvNZeTVOfLJ
5PWzIo67MwlpxCvnDKSS
What is a stroke: https://www.youtube.com/watch?v=uLJewzJcCZ0
When this reduction of blood flow in the vertebral artery is missed, manipulation of
the cervical spine increases the risk on TIA and stroke.
TIA is often misdiagnosed as migraine, seizure, anxiety or peripheral neuropathy.
The test
To test the blood flow in the vertebral artery, the osteopath puts the patient supine
and performs a passive extension, followed by a passive rotation of the neck. The
rotation must be performed in both directions.
The technique causes a reduction of the lumen at the third division of the vertebral
artery, resulting in decreased blood flow of the intracranial vertebral artery of the
contralateral side. This causes an ischemia due to blood loss in the pons and the
medulla oblongata of the brain. It results in:
dizziness,
nausea,
syncope,
dysphagia,
dysarthria,
hearing disturbance,

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vision disturbance,
paresis or paralysis.
The test can also be done sitting: https://www.youtube.com/watch?v=sxXZzUomTuQ
The test is already in use 30 years although there was never enough prove of the
reduction of the lumen of the vertebral artery. The test is therefore controversial.
The review of Mitchell et al.,2007 found that, from the twenty studies reviewed, four
studies measured the blood flow in the transverse part of the first division, eleven in
the second division, none in the third division and five in the fourth division. In 7 of
the 20 studies, there was not found any loss of blood flow in the vertebral artery.
Therefore, there will be false positive/negative blood flow results in cervical spine
rotation. The controversial findings in today’s literature cannot be used to guide
evidence-based practice except to support the need for educated caution and
authority in the pre-treatment screening and treatment of the patients.
‘Côté et al.’ say that the positive predictive value of this test (the proportion of
subjects with a positive test who are correctly diagnosed) is 0%, and the negative
predictive value of this test ranged from 63%-97%. The test was found not valid
enough to detect a reduced blood flow in the vertebral artery. Therefore, the value of
this test is questionable, especially when the rotation amplitude in the neck is
reduced.
Literature
Jeanette Mitchell; Doppler insonation of vertebral artery blood flow changes
associated with cervical spine rotation: Implications for manual therapists;
Physiotherapy Theory and Practice; 2007; 23(6):303-313.
Côté P et al.; The validity of the extension-rotation test as a clinical screening
procedure before neck manipulation: a secondary analysis; J Manipulative
Physiol Ther;. 1996 Mar-Apr;19(3):159-64[A2]
Rushton A, Rivett D, Carlesso L, Flynn T, Hing W, Kerry R. International
Framework for Examination of the Cervical Region for potential of Cervical
Arterial Dysfunction prior to Orthopaedic Manual Therapy Intervention. 2012 :

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http://www.ifompt.org/site/ifompt/files/pdf/Standards%20Committee/Standards
%20Committee%20Documents//IFOMPT%20Examination%20cervical%20spi
ne%20doc%20September%202012%20definitive.pdf