About 1 in 50,000 people suffer vertebral artery dissection each year, with the average age being 39-45 years old (Arnold and Bousser, 2005). Although "vertebral artery dissection" does not appear on our contraindications list, some of the warning symptoms are on the absolute general list. "Sudden onset of sever undiagnosed headache (which you will find on the absolute general contraindication list) is one of the hallmark symptoms of vertebral artery dissection Although it is difficult to predict who is at risk for a vertebral artery dissection, it has been linked to migraine headaches, hypertension, oral contraceptive pills, and tobacco use (Leon-Sanchez, Cuetter, and Ferrer, 2007)". Other risk factors may include trauma or infection the blood vessel or some underlying fault with the vessel wall, such as connective tissue disorders seen in Marfan's Syndrome, Ehlers-Danlos Syndrome, and hyperhomocyseinemia (Pezzini, et al).

The most obvious signs and symptoms of a vertebral artery dissection are pain in the head and neck, often unilateral and suboccipital. The onset is often acute and may or may not be associated with a recent trauma to the head or neck. The pain is often described as intense and sharp. Although neck stiffness may be reported, a restricted range of motion is not associated with VAD. Other symptoms associated with vertebro-basilar insufficiency may also be present, including dizziness, ataxia, nausea, numbness, and diplopia. The time delay between onset of the VAD and symptoms may range from hours up to 14 days.

Any patient that is suspected to have a vertebral artery dissection should immediately be sent to a physician before any physical assessment or treatment is performed. It is important to differentiate between regular musculoskeletal pain and a VAD through careful patient history taking. As mentioned, any sudden undiagnosed headache, particularly in the occipital region should be suspect of VAD. If VAD is a possibility, do not physically assess the head or neck, as some movements of the neck may be associated with compromise to the cervical blood vessels (2, Yokota, Amakusa, Tomita, and Takahashi, 2003, 58, 59, 63). Treatment of the head and neck of a patient that has sustained a recent vertebral artery dissection could lead to lethal brain stem infarction (94).

"cervical artery dissection"
"internal carotid artery dissection"
"Horner's syndrome"
"Wallenberg's syndrome"

2) prevalence of condition

"-mainly seem to affect young and middle-aged people
-2-3 per 100 000 per year
-25% of all dissections are vertebral
-no male/female predominance
-mean age is 39-45 years old" (38)

"-etiology is unexplained, but most likely involves underlying fault with vessel walls, as well as some sort of trauma or infection (38)"

"82% diagnosed with SDCVA were caucasion, 53% male, average age 41.5 (55)"

"most frequent cardiovascular risk factors were systemic hypertnesion and tobacco use (55)"

"3 main consequences of dissection:

retinal/brain ischemica caused by embolization or thrombus to retinal artery or intracranial vessels
compression or stretching, due to enlarged artery and any aneurysm, causes local symptoms such as pain, Horner’s syndrome, and cranial nerve palsies subadventitial rupture of dissected artery (mostly intracranial vertebral), causes subarachnoid or intracerebral hemorrhage" (38)

"-in 15-20% of patients, multivessel cervical artery dissections occur at once" (38)

"The most common risk factors are migraine, hypertension, oral contraceptive pills and smoking (57)".

The cause of cervical artery dissections is largely unexplained. It most likely involves an underly-

ing abnormality of the vessel wall (Brandt et al. 2001) as well as triggering factors such as trauma
or infection (60)".

"our findings show that VA dissection affects mainly middle age persons and involves both sexes equally. Headache/and or neck pain followed by vertigo or unilateral facial paresthesia is an important warning sign that may precede onset of stroke by several days (95)".

3) relevant literature

(1) Mitchell, J.(2009). Is mechanical deformation of the suboccipital vertebral artery during cervical spine rotation responsible for vertebrobasilar insufficiency? Physiotherapy Research International, 13(1), 53-66.

(2) Li Y., Zhang Y., Lu C., Zhong, S. (1999). Changes and implications of blood flow velocity of the vertebral artery during rotation and extension of the head. Journal of Manipulative and Physiological Therapeutics, 22 (2).

(3) Pego, R., Marey, J., Lopez-Facal, M.S., Marin-Sanchez, M. (1996). Eight cases of extracranial vertebral artery dissection. Revista de Neurologia, 24(126), 172-5.

(4) Watanabe, M., Murayama, T., Mano K., Watanabe, H., Kanamori, M. (1996). Medial medullary infarction following neck manipulation. Rinsho Shinkeigaku, 36(1), 43-6.

(5) Sengoky, R., Sato, H., Honda, H., Inoue, K., Ono, S. (2006). Skin collagen abnormalities in a Japanese patient With Extracranial Internal Carotid Artery Dissection Followed by Extracranial Vertebral ...Rinsho Shinkeigaku. Feb, 46 (2), 140-143.

(6) Saxler, G., Schopphoff, E., Quitmann, H., Quint, U. (2005). Spinal manipulative therapy and cervical artery dissection. HNO, 53(6), 563-7.

(7) Pieri, A., Spitz, M., Valiente, R., Avelar, W., Silva, G., Massaro, A. (2007). Spontaneous carotid and vertebral arteries dissection in a multiethnic population. Arq Neuropsiquitr, 65(4A), 1050-5.

(8) Nagumo, K., Nakamori, A., Kojima, S. (2003). Spontaneous intracranial internal carotid artery dissection: 6 case reports and a review of 39 cases in the literature. Rinsho Shinkeigaku, 43(6), 313-21.

(9) Yokota, J., Amakusa, Y., Tomita, Y., Takahashi, S. (2003). The medial medullary infarction (Dejerine syndrome) following chiropractic neck manipulation. No To Shinkei, 55(2), 121-5.

(10) Taniguchi, A., Wako, K., Naito, Y., Kuzuhara, S. (1993). Wallenberg syndrome and vertebral artery dissection probably due to trivial trauma during golf exercise. Rinsho Shinkeigaku, 33(3), 338-40.

(11) Shimizu, J., Nakagawa, Y., Nakase, H., Mannen, T. (1992). Wallenberg's syndrome due to vertebral artery dissection following minimal neck injury--report of two cases. Rinsho Shinkeigaku-Clinical Neurology, 32(4), 430-5.

(12) Menendez-Gonzalez, M., Garcia, C., Suarez, E., Fernandez-Diaz, D., Blazquez-Mene, B. (2003). Wallenberg's syndrome secondary to dissection of . Rev Neurol, 37(9), 837-9.

(13) Yi-Kai, L., Yun-Kun, Z., Cai-Mo, L., Shi-Zhen, Z. (1999). Changes and implications of blood flow velocity of the vertebral artery during rotation of the cervical spine. Journal of Manipulative and Physiological Therapeutics, 22(2).

(14) Mitchell, J. (2003). Changes in vertebral artery blood flow following n...[J Manipulative Physiol Ther. 2003 Jul-Aug] - PubMed Result.pdf Journal of Manipulative and Physiological Therapeutics, 26(6), 347-51.

(15) Canadian Chiropractic Association, Canadian Federation of Chiropractic Regulatory Boards, Clinical Practice Guidelines Development Initiative, Guidelines Development Committee (2005). Chiropractic clinical practice guideline-evidence-based treatment of adult neck pain not due to whiplash. Journal of the Canadian Chiropractic Association, 49(3), 158-62.

(16) Clinical Manifestations of Vertebral artery dissection.pdf

(17) Haldeman, S., Carey, P., Townsend, M., Papadopoulos, C., Clinical perceptions of the risk of vertebral artery dissection after cervical manipulation- the effect of referral bias.

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(31) A Systematic Review of the Risk Factors for Cervical Artery Dissection -- Rubinstein et al. 36 (7)_ 1575 -- Stroke.pdf

(32) Adverse effects of spinal manipulation- a systematic review E Ernst.pdf

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(35) Arquivos de Neuro-Psiquiatria - Spontaneous carotid and vertebral arteries dissection in a multiethnic population.pdf

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(38) Carotid and Vertebral Artery Dissection -- Arnold and Bousser 5 (2): 100 -- Practical (39)Neurology.webarchiveCarotid and Vertebral Artery Dissection -- Arnold and Bousser 5 (2): 100 -- Practical Neurology.webarchive

(40) Carotid artery blood flow during premanipulative t...[J Manipulative Physiol Ther. 2002 Nov-Dec] - PubMed Result.pdf

(41) Carotid artery blood flow during premanipulative testing.pdf

(42) Causes of complications from cervical spine manipu...[Aust J Physiother. 2001] - PubMed Result.pdf

(43) causes of complications from cervical spine manipulation.pdf

(44) Causes of complications from cervical spine manipulation Mann T, Refshauge KM.pdf

(45) Causes of complications from cervical spine manipulation Mann T, Refshauge KM .pdf

(46) Cervical artery dissection--clinical features, ris...[J Neurol. 2003] - PubMed Result.pdf

(47) Cervical artery dissection--clinical features, risk factors, therapy and outcome in 126 patients Dziewas R, Konrad C, Drager B, Evers S, Besselmann M, Ludemann P, Kuhlenbaumer G, Stogbauer F, Ringelstein EB.pdf

(48) Cervical artery dissection. A comparison of highly...[J Manipulative Physiol Ther. 2005] - PubMed Result.pdf

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(50) A narrative review of pathophysiological mechanisms associated with cervical artery dissection.pdf

(51) Arnold, et al (will add full reference later)

(52) Campus, et al (will add full reference later)

(53) Kalashnikova, et al (will add full reference later)

(54) Pezzini, et al (will add full reference later)

(55) Spontaneous Dissection of the Carotid and Vertebral Arteries, Wouter I. Schievink, M.D., New England Journal of Medicine. volume 344:898-906, March 22, 2001
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(56) [The medial medullary infarction (Dejerine syndrome) following chiropractic neck manipulation], Yokota J, Amakusa Y, Tomita Y, Takahashi S., No To Shinkei, 2003 Feb;55(2):121-5
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(57) Cervical spine manipulation: an alternative medical procedure with potentially fatal complications referral bias. Leon-Sanchez A, Cuetter A, Ferrer G, South Med J. 2007 Feb;100(2):201-3.
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(58) Effect of premanipulative tests on vertebral artery and internal carotid ar....pdf
(59)Changes and implications of blood flow velocity of the vertebral artery dur....pdf

(60) carotid and vertebral artery dissection.pdf

(61) Hyperhomocysteinemia_ a potential risk factor for ...[J Neurol. 2002] - PubMed Result.pdf

(62) Infarction of the Medulla and Cervical Cord After Fitness Exercises .pdf

(63) Is it time to stop functional pre-manipulation testing of the cervical spine? .pdf
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(65) Is there a role for premanipulative testing before cervical manipulation?.pdf

(66)Ischemic symptoms induced by occlusion of the unilateral vertebral artery with head rotation together with contralateral vertebral artery dissection--case report..pdf

(67) Life-Threatening Complications of Spinal Manipulation -- Ernst 32 (3)_ 809 -- Stroke.pdf

(68)Manipulation of the Cervical Spine_ Risks and Benefits -- Di Fabio 79 (1)_ 50 -- Physical Therapy.pdf
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(73)Ovid_ Search Results.pdf
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4)when and why it is dangerous to work on a patient with that condition
The symptoms of VAD can be mistaken for musculoskeletal pain, so it is important to rule out VAD with any person complaining of occipital and/or neck pain.

For those who are at risk of VAD (or who have already had it happen) are at risk for further damage to the vertebral artery if the neck is put in a position of rotation and/or extension. For some of these patients, the consequences could be catastrophic, as further extension to the artery could cause fatal brain stem infarction. It is important to know who is at risk for VAD and to know the symptoms of VAD. Even mild trauma can result in VAD.

It is important to know who is at risk for VAD (those with connective tissue disorders, compromised blood vessel stability, possibly those experiencing an infection such as a cold or flu at the time of treatment, smokers, those taking the oral contraceptive pill, hypertension, and those who have recently experienced any kind of trauma to the head or neck).

Extreme rotation of the C-spine may cause compromised vertebral artery blood flow, which may particularly affect those people with compromised vascular stability.

It is very important to know the signs and symptoms of VAD (see signs and symptoms) and refer the patient to a physician immediately if VAD is suspected.
Various studies have suggested that the vertebral artery test may not be reliable as a screening tool for VAD or other cervical vertebral instabilities.
Although it has not been established as to whether or not chiropractic manipulation can cause VAD directly, vertigo following a chiropractic manipulation, VAD should be suspected and investigated. Rose's position (supine with head and neck extended off the end of the table) should be avoided.

A major contraindication to cervical treatment is unusual acute occipital headache.

5) the signs and symptoms to watch for (red flags)
unusual acute occipital headache!

Clinical features of vertebral artery dissection and brainstem ischemia arising from vertebral artery insufficiency

Historical and clinical features suggestive of vertebral artery dissection

Most common presenting symptoms are pain in the head and neck (in almost 90% of cases), often unilateral and sub-occipital

Patient often never experienced a similar pain before

Onset often acute, may be related to trauma or spontaneous. Distinction between traumatic and spontaneous quite arbitrary—spontaneous

usually means no major trauma (RTA, fall). Detailed and careful history may reveal minor or trivial trauma (sports activities, painting the ceiling,


Searching for these things preceding the neck pain or headache may raise suspicion.

Pain has distinct, but non-specific features, intensity often severe and quality sharp

Patient may report a sensation of neck stiffness, but there is no limitation of ROM

Time delay between onset of symptoms and clinical features of brainstem ischaemia can range from hours to up to 14 days

Clinical features suggestive of brainstem ischaemia arising from vertebral artery insufficiency

Major (most common) symptoms of vertebro-basilar insufficiency are:
Dizziness/vertigo/giddiness/light headedness

Nausea (often with vomiting)

Numbness—most often unilateral facial; less commonly may involve trunk and limbs (contraversive or ipsiversive)

Ataxia/unsteadiness of gait is the most common


(Patient may report limb weakness—uncommon feature)

Major (most common) neurological signs are:

Ipsilateral Horners syndrome

Ipsilateral limb ataxia

Gait ataxia

Ipsilateral sensory abnormalities of face (CN V); most commonly a loss of pain and temperature (dissociated sensory loss); can get diminished/

absent ipsilateral corneal reflex

Contraversive sensory abnormalities of trunk and limbs; most commonly dissociated (alternating analgesia)
Ipsilateral cranial nerve IX–XII abnormalities

Nystagmus; cerebellar or vestibular in origin

Possible ipsilateral cranial nerve VII deficit

Possible pyramidal signs; uncommon and often seen in isolation

Most clinical features arise from the territory of the posterior-inferior cerebellar artery (Wallenberg Syndrome)

"local symptoms:

-occipital headache/posterior neck pain or both are the early findings in most patients (51),(38),(52),(60)
-pain is mostly unilateral/ipsilateral to side of dissection, but can also be bilateral (38),(60)
-only half of these people will describe pain as worrying intensity (38),(60)
"The typical clinical manifestation is posterior neck pain or occipital headache or both, usu
ally more marked on the side of the dissection,
followed often after a time delay, by posterior circulation ischaemia. It is often as
sociated with major or minor neck or head
trauma (60)".

local signs:

-clinical examination usually does not reveal impaired neck mobility (38)
-may be mistaken for torticollis (patient may be reluctant to have neck moved) (38)
-cervical nerve roots may be compressed or stretched (38)
-more than 80% of patients develop posterior circulation ischemia (38)
-lateral medullary infarction is common (ipsilateral neck pain, sensory disturbance on ipsilateral face, nystagmus, ipsilateral limb ataxia and pain loss in contralateral hemi-body (38)"

Differential Diagnosis:

"-migraine (aura, photophobia, phonophobia, nausea, vomiting) (38)
-cluster headaches (presenting with unilateral face pain) (38)
-Horner’s syndrome (ptosis, constricted pupil, dilation lag, flushing of affected side of face) is clue to diagnosis(38)

"• Any sudden headache perceived by a migraine as different from his or her usual migrainous headache should be investi-
gated on an emergency basis – it might be a dissection.
• A sudden headache, like a thunderclap (with or without subarachnoid haemorhage), or neck pain may be the only symptom
of carotid or vertebral dissection.(38), (60)"

6) references to research that support the reasons why this condition is a CI

"The symptoms of vertebral artery dissection may be mistaken for musculoskeletal pain. Manipulation of the neck may have catastrophic consequences with upward extension of the dissection and may lead to lethal brain stem infarction (57)"

"In a half of patients, cerebral ischemic symptoms developed after neck movements or manual therapy (53)."

“Extreme rotation of the cervical spine may cause compromised vertebral artery (VA) blood flow. This is of particular interest to manual therapists because of the potential risks associated with these movements (2)."

"Maximal rotation of the cervical spine may significantly affect vertebral artery blood flow, particularly when used in the treatment of patients with underlying vascular pathology (2)"

"Hyperhomocysteinemia may represent a potential risk factor for manipulation-related CAD, leading to structural abnormalities of the arterial wall and increasing the susceptibility to mechanical stress (54)."

"possible rotation and tilting of neck stretches and compresses the VA at the cervical joint causing injury to vessel (56)"

"more attention should be paid to trivial trauma as cause of stroke, especially in younger population (this case study involves a 57 year old man suffering a VAD after golfing exercises that included quick extension and/or neck rotation)" (10)

In one study, two cases of VAD were presented and were thought to have been caused by mild trauma (1. frequent neck rotation due to posterior neck discomfort 2. prolonged hyperextension of neck while painting a wall), suggesting that cervical rotation and extension were thought to precipitate the dissections (11).

In one study, a young patient develops wallenberg symptoms a few hours after a cervical chiro manipulation (12)

"Spontaneous cervical artery dissection (SCAD) is one of the causes of stroke in young adults. The pathogenesis of SCAD remains unknown. Minor trauma like an excessive sneeze, migraine, and connective tissue disorders such as fibromuscular dysplasia and Ehlers-Danlossyndrome are well-known as risk factors for SCAD” ( )1

"Developmental variants, post traumatic degenerative changes of the the hyoid apparatus may result in different degrees of ossification or calcification. The condition of the hyoid apparatus should be considered in differential diagnosis of facial and neck pain, especially when manipulating the upper C-spine. C-spine manipulation may exacerbate existing pathological conditions of the stylohyoid apparatus, which may cause fracture or irritate surrounding neurovascular structures. The developmental ossification of this apparatus may be associated with anomalies in the atlantic section of the vertebral artery ( )2".

In one study, it was demonstrated that cervical extension is dependent on cervical rotation and the "free length" of the vertebral artery in the upper cervical spine. Between July 2002 and February 2004, this study received and registered 5 vertebral artery dissections with subsequent brain infarctions (6).

"The most frequent clinical manifestation of vertebral artery dissection is posterior headache or neck pain, accompanied or followed by posterior circulation transient ischemic attack or stroke. Rarer clinical features include isolated headache or neck pain, cervical spinal cord ischemia and cervical root impairment. Asymptomatic vertebral artery dissections have been reported. In the case of primary intracranial vertebral artery dissection or intracranial extension of an extracranial dissection, subarachnoid hemorrhage and rarely rostral cervical spinal cord ischemia or posterior fossa mass effect may occur (51)".

"The typical clinical manifestation is posterior neck pain or occipital headache or both, usually more marked on the side of the dissection, followed often after a time delay, by posterior circulation ischemia. It is often asociated with major or minor neck or head trauma (38)".

"Data from this study lend support to recommendations favouring imaging studies of the cervical arteries in patients with new-onset unexplained headache or neck pain (52)."

"The lack of identifiable risk factors place those who undergo CSMT at risk of neurologic damage. Accurate patient information and early recognition of the symptoms are important to avoid catastrophic consequences (57)".

"Hyperhomocysteinemia may represent a potential risk factor for manipulation-related CAD, leading to structural abnormalities of the arterial wall and increasing the susceptibility to mechanical stress (61)".

"Neck manipulation occasionally causes stroke after trauma to the vertebral or internal carotid artery. Premanipulative tests involving
cervical spine rotation or extension have been recommended to detect
patients at risk of neurovascular ischemia. However, the effect of these
procedures on extracranial blood flow is not well established, and their
validity is thus controversial (58)".

"It is widely recognized that passive therapeutic maneuvers applied to the
cervical spine are associated with a small risk of iatrogenic stroke. The
most frequent cause is trauma of the vertebral artery (VA), although the
internal carotid artery (ICA) is occasionally involved (58)"

"Although the precise incidence rate of these
events is unknown, they seem to be very uncommon, if not rare, occurrences (58)"

" In spite
of the infrequency of neurovascular complications in relation to other conservative interventions, their potentially serious nature has led to
some manipulative practitioners recommending premanipulative tests
designed to detect "at risk" patients (58)"

"The rationale for these positional tests was originally derived from the results of cadaveric studies that demonstrated that the contralateral VA
was sometimes occluded on rotation, extension, or on combined
rotation/extension (58)"

"For the VAs there seems to be a trend of decreasing blood flow velocity (as measured with Doppler sampling in the region between the second
and third cervical vertebrae) with increasing degrees of rotation. End-
range contralateral rotation significantly reduced PS blood flow velocity
for both VAs (58)"

"Refshauge hypothesized that, at end-range rotation, narrowing of the vessel diameter may reach a critical level whereby blood viscosity becomes a
factor leading to slowing of the blood flow. The combination of a
relatively small vessel orifice (because of positional narrowing) and red
blood cell viscosity may result in a decelerating effect known as viscous
friction. Alternatively, the decrease in flow velocity observed in the
rotatory positions may reflect the fact that the site of sampling is
upstream of the likely site of vessel narrowing, the atlanto-axial region.
Thus the blood flow approaching this region may tend to slow, whereas
the flow velocity at the actual site of narrowing will tend to increase to
maintain a constant flow volume (58)".

"The negative group reported no signs or symptoms of neurovascular
insufficiency during the ultrasound examination, and yet there was
demonstrable change in their extracranial blood flow. In fact, one subject
experienced total occlusion of the left VA in end-range rotation and also
combined end-range rotation/extension on repeated testing. This case is
described in detail elsewhere; however, it serves to illustrate that
the VA may be markedly stressed and effectively ligated and yet the
clinical test result is negative (58)".

"Thus, from a clinical perspective, a negative result to premanipulative
testing does not guarantee that the proposed manipulative procedure is
entirely free of risk (58)."

"It can therefore be argued that the patient at risk of manipulative stroke
is often undetectable in spite of the use of premanipulative tests (58)".
"The results of this pilot study provide preliminary evidence that changes
in neck position influence blood flow in the extracranial arteries. In
particular, the vertebral artery is subjected to forces in positions involving
end-range contralateral rotation that are sufficient to significantly reduce
blood flow velocity (58)".

"Extreme rotation and extension are dangerous to patients
who have abnormal vertebral arteries when extreme rotatory and
extension manipulations are applied. Doctors should be very careful when
rotating the patient's head to the right side (59)"

"The cadaveric results showed that the drops in the bilateral vertebral
artery reduced significantly during extreme extension of the head (59)".

and vertigo occurred in a few subjects at a position of extreme extension and extension-rotation of the head, and the blood flow velocities became
slower than those of other subjects and students during the TCD
measurement. This indicated that extension and extension-rotation of the
head caused extrinsic compression of the vertebral arteries sufficient to
cause such changes of blood flow velocities and potentially create acute
ischemia of the brain in these subjects. Extreme extension-rotation of the
head probably has a greater effect on the velocities of the vertebrobasilar
arteries than simple extension of the head (59)".

"The position of extreme
extension of the head should be avoided during cervical manipulation in patients who are suspected of having ischemia of the vertebrobasilar
arteries. Extreme extension-rotation of the head should also be avoided. In this position ischemia of the brain may occur and cause irreversible

brain injury (59)".

"Ischemia of the vertebrobasilar arteries is a frequently encountered
disease in middle-aged and older people. Its diagnosis depends on
symptoms of dizziness, so it has lacked an objective criterion (59)".

"The instillation test of the vertebral artery and clinical TCD sonography
measurements suggested that the extreme extension and extension-
rotation of the head had significant effects on the blood flow velocities of
vertebral arteries in some subjects. In patients who had atherosclerosis,
stenosis, obvious anatomic variations of vertebral artery, low
autoregulation of the cerebral vessels, and in those patients who were
under general anesthesia or who were comatose, the vertebral artery
would be more easily injured by cervical manipulation if the heads were
rotated or extended. The sharp reduction of blood flow velocities in the
vertebral arteries indicates that the blood supply to the brain also had a
sharp decline and is likely one of the main reasons why accidents from
cervical manipulations may occur (59)".

"It is noticeable that the right vertebral
arteries had more disorders or insufficiency of blood supply than the left (59)".

may be one of the most common symptoms of ischemia in the brain (59)".

"Vertebral artery dissection account for about 24% of all dissections (60)".

"Manipulation of the neck, minor falls, pro-
longed hyperextension of the neck, and abrupt head turning have all been described as causes of occlusion of a vertebral
artery, leading (rarely)ischemia or infarction (61)"

"While most cases of induced vertebral artery
damage; reported in the literature have been caused by cervical manipulation, including chiropractic,
yoga has been incriminated in three reports. Neck trauma, bow hunting, athletic injuries, neck
hyperextension, and atlantoaxiat dislocations have
also been incriminated,
as has head-turning while driving an automobile and while leading a parade. Spontaneous dissections
have been regarded as rare, but vessel wall disease
such as cystic medial necrosis, arteritis, and fibro-muscular hyperplasia may be predisposing causes (62)".

"The vertebral arteries
penetrate the atlanto-occipital membrane and the cervical dura, having emerged from the transverse
foramina of the first cervical vertebra; it is at this
level that at least 50% of rotation occurs during head turning. Angiography during head rotation has
shown such vertebral artery compression at Cl,
associated with the development of symptoms of brainstem ischemia,1314 and even in normal sub-
jects vertebral arterial flow may be reduced or even
halted when the head is maximally turned to the opposite side (62)".

"The combined extended and rotated cervical spine position has been postulated to affect vertebral artery blood flow by primarily causing a narrowing of the vessel lumen, usually within the artery contralateral to the side of head rotation. The production of brainstem symptoms during the manoeuvre has generally been considered to be a positive test result. As a consequence, functional pre-manipulation testing of the cervical spine has been part of clinical screening undertaken by chiropractors and other manual practitioners to rule out the risk of possible injury to the vertebral artery (63)".

"Since first reported in the literature in 1927 by DeKleyn and Nieuwenhuyse, the combined extended and rotated cervical spine position has been postulated to affect vertebral artery blood flow by primarily causig a narrowing of the vessel lumen, usually within the artery contralateral to the side of head rotation. The production of brainstem symptoms during the manoeuvre has generally been considered to be a positive test result (63)".

"The vertebral artery insufficiency test is used for screening or diagnostic purposes when there is the absence of historical or other clinical features suggestive of vessel pathology such as dissection, and/or brainstem ischaemia (63)".

"Furthermore, in this scenario (in which someone has weakened vessel walls) performing these tests alone may possibly put the patient at a higher risk due to the potential stretching forces exerted on an already weakened vessel wall (63)".

"Although there are no documented cases of dissection following pre-manipulation testing alone, the literature cites many examples of non-manipulative positional
manoeuvres of the head and neck that have been associated with cerebrovascular injury (63)".

"Vertebral artery test has the potential to further occlude a vessel that is already affected by a pre-existing thrombus formation in the vertebral aretery. This could result in sufficient alteration in the arterial flow characteristics to produce ischemic brainstem symptoms. It is also conceivable that the test may dislodge the embolus resulting in a stroke (63)".

"If there is a strong likelihood of VAD, provocative tests should not be performed, and the patient must be referred appropriately (63)".
"Before the vertebral artery enters the base of the skull and becomes the basilar artery, it changes in direction from a vertical path to a horizontal path, at which point it is susceptibleto injury from rotation or extension. It has been hypothesized that cervical manipulation may cause dissection or occlusion of the posterior (vertebrobasilar) arteries as they are stretched during the rotation or tilting of the neck. Either injury can result in ischemia and brain injury (72)."

"Single-vessel cervical arterial dissections typically occur in young
adults and are a common cause of cerebral ischemia and stroke. Although the pathogenesis of multivessel dissection is unclear, it is thought to be a consequence of underlying collagen vascular disease (79)"

"Peak velocity of blood flow of vertebral artery was less in both vertebral arteries on return to the neutral position from the 45º angle and end range of the c-spine, however the difference was only significant for the left side. This supports the idea of giving a rest period between neck movements when doing cervical movement tests when conducting pre-manipulative testing, to allow for any latent effect on blood flow of the tests themselves. There were no change in volume flow rate between any of the test positions. There was no indication of a cumulative effect of the test procedure (80)"
"Asymptomatic vertebral artery injury is found in up to 19% of all patients who incur trauma to the lower cervical spine. This incidence increases in flexion-distraction deformities (81)."

"The static deformity of flexion-distraction Stage 2-4 subaxial cervical injuries results in significant objective compression of the vertebral vasculature (81)"

"To our knowledge, the only one report has been made by Watanabe and his colleagues before our present case. The mechanizmwas suggested that rotation and tilting of the neck stretches and compresses the vertebral artery at the cervical joint causing injury to the vessel, with an intimal tearing, dissection, and pseudoaneurysm formation. Consequently, the present case may be caused by injury to the left vertebral artery with an intimal tearing during neck manipulation sufficient to cause dissection and subsequent infarction of the brain stem (82)"
"There are several factors that may cause a reduction in vertebral artery blood flow. These include exostoses (the formation of a new bone on the surface of a bone), such as the retroarticular canal and lateral bridge of the atlas vertebra that may cause compression of the related part of the verteral artery; or atherosclerosis of the artery wall occluding the vessel lumen. Functional factors, such as sustained end-of-range rotation of the cervical spine, may cause distortion of the vertebral artery in the suboccipital region, which may be reflected as decreased blood flow in the suboccipital and intracranial parts of the artery. A combination of such factors is likely to cause reduced blood flow to the hindbrain (84)."
"In one study, vertebral artery injuries/occlusions were investigated using magnetic resonance angioraphy (MRA). Only one of the 10 patients with a vertebral artery occlusion was symptomatic. Vertebral artery occlusion was rarely symptomatic because of the sufficient collateral blood supply through not only contralateral vertebral artery, but also the circle of willis (85)"
"In one case, a woman was uneventfully treated with cervical manipulation in the presence of a damaged vertebral artery. The paper suggests that this case demonstrates that vigorous manipulation of the upper cervical spine is possible without injuring an already damaged vertebral artery. It is then suggested that it is currently impossible to identify patients at risk of having a dissected vertebral artery with standard in-office examination procedures, rotational manipulation of the upper cervical spine should be abandoned by all practitioners, and schools should remove such techniques from their curriculums (86)"
"Cerebrovascular accidents after manipulation appear to be unpredictable and should be considered inherent, idiosyncratic, and rare complication of this treatment approach (87)"

"Vertebral artery dissection is rare and can occur without a known history of neck trauma and in the absence of any apparent underlying vascular disease. In most instances, however, there is a documented injury to the neck, often of a trivial nature (88)".
"Some reported cases of vertebral artery dissection might have had morphological abnormalities which would not be readily recognised with routine methods of investigation and in which quantitative techniques might help to explain-for example, why only a small percentage of people who undergo neck manipulation die (88)".
"We emphasis that cervical manipulation should be performed only in patients without predisposing factors for artery dissection and after an appropriate diagnosis of neck pain (89)".
"There is a suspicion of increased risk for vertebrobasilar stroke for vertebral arteries that have markedly reduced patency in the neutral position and/or stenosis during cervical rotation. There is evidence that provocational tests lack validity and that Doppler velocimetry is valid in assessing the patency of vertebral arteries in the neutral position and during cervical rotation (90)".
"We emphasise that a history of subtle precipitating events be taken while diagnosing young patients with brain stem strokes, to recongnise this clinical entity. Although mechanisms are not absolutely clear, yet there seems to be an important relationship between arterial dissection and neck movements or minor trauma (91)".

"Vertebral artery dissection has a characteristic presentation that should be considered when symptoms are preceded by any trauma that causes neck movement (92)".
"Neck pain, one of the hallmark symptoms of VAD in adults, was infrequently noted in this young population. Most children presented with various combinations of symptoms and signs, including ataxia, headache, and vomiting (93)".
"There is a very high incidence of associated cervical anomalies in children with VAD (93)".
"Vertebral artery dissection is rarely considered as a diagnostic possibility unless brainstem or cerebellar ischemia follows the acute pain (94)".
"A high degree of suspicion especially in young patients with no past history of a similar pain can help to establish the diagnosis, thereby preventing erroneous and potentially hazardous therapeutic interventions such as physiotherapy or neck manipulation (94)".
"Risk factors associated with artery dissections (e.g. fibromuscular dysplasia) were present in only 24% of subjects (referring to a study done involving VAD associated with chirotherapy of the neck) (95)".
"Major changes in peak flow velocity might in theory explain the pathophysiology of cerebrovascular accidents after spinal manipulative therapy. HOwever, in uncomplicated spinal manipulative therapy, this potential risk was not prevalent (in a study done on spinal manipulative therapy and vertebral artery flow) (97)".

"Our results indicate that in symptom-free subjects there is no change in vertebral artery perfusion during rotation in spite of significant changes in flow velocity. This finding, as well as the observed changes in flow velocity reported by others, may be explained by a positional change in the vertebral artery diameter (98)".

"major contraindications to cervical manipulation: unusual acute occipital headache (99)".

"A VA dissection should be suspected in a case of vertigo following chiropractic neck manipulations, and vestibular tests should be done carefully, avoiding Rose's positions (a supine position with the head over the end of the table) (100)".

7)OPTIONAL: benefits of massage for this condition