Vertebrobasilar insufficiency and cervical manipulation

The term “vertebrobasilar insufficiency” (VBI) encompasses all transient ischemic attacks (TIAs) of the posterior circulation of the brain. Vertebrobasilar insufficiency is the hardening of the vertebral artery due to the accumulation of arteriosclerotic plaque and calcium. This makes the artery vulnerable to cervical vertebral manipulation. Although injury to the artery is rare following spinal manipulation, it is crucial to check its integrity before spinal manipulation.

The vertebrobasilar arterial system supplies blood, oxygen, and nutrients to vital brain structures, such as the brainstem, occipital lobes, and cerebellum. It is possible that this system has atherosclerosis, which is the hardening of the arteries, caused by the accumulation of cholesterol and calcium plaque. Too much plaque will reduce or even stop blood flow. The brain and cerebellum will then be in vertebrobasilar insufficiency (VBI).

Anatomy

• An important difference between cervical regions and other vertebral regions is the presence of vertebral arteries.
• These branches start from the subclavian artery and cross the transverse foramen of each cervical vertebra from C6 and above.
• When the artery reaches the atlas, it runs almost horizontally and then enters the foramen to join with its neighbor and form the basilar artery.
• Vertebral arteries provide about 11% of cerebral blood flow, with the carotid system providing 89% (Grant, 1994a).
• Approximately half (45-50 degrees) of cervical rotation occurs primarily at the atlanto-axial joint.
• During head rotation, because the vertebral artery is attached to the transverse foramina C1 and C2, it will be stretched/tensed, compressed and twisted.
• The rotational movement produces the greatest decrease in blood flow to the vertebral artery (deKleyn and Nieuwenhuyse, 1927; deKleyn and Versteegh, 1933; Tatlow and Bammer, 1957; Toole and Tucker, 1960; Brown and Tatlow, 1963 Andersson et al., 1970; Barton and Margolis, 1975; Grossman and Davies, 1982; Yang et al., 1985).

• Dizziness (the most common symptom)
• Dizziness/syncope: Sixty percent of TBI patients experience at least one episode of dizziness.
• The patient suddenly feels weak in the knees and falls.
• Diplopia/loss of vision
• Paresthesia
• Confusion
• Dysphagia/dysarthria
• Headache
• Altered consciousness
• Ataxia
• Contralateral motor weakness
• Loss of temperature and pain
• Incontinence

• The insufficient vertebral artery will be more vulnerable to cervical manipulation.
• When the vertebral artery leaves the transverse foramen of C2 (axis), it must suddenly change direction in order to join the transverse foramen of C1 (atlas).
• So, this is where a manipulative fit can sever the vertebral artery.
• Rotating cervical manipulation puts a lot of strain on the spinal artery at the C2 level.
• Dizziness and lightheadedness are among the symptoms commonly encountered.
• Young people can be affected by VAD, however, older people are most affected. (1)
• Smith et al suggested that cervical manipulation independently increases the risk of VAD with stroke by about six-fold. (2)
• Rates of VAD after cervical manipulation of 1 in 10,000 to 1 in 2 million have been reported, (3-4)
• As a therapist it is important to recognize the possibility of having a patient with an IVM.
• Although the possibility of DVB is minimal, this does not preclude testing the integrity of the artery before handling a patient.

Trauma to the vertebral artery following cervical manipulation occurs primarily in its atlantoaxial component, which is stretched forward during rotation.

• Headaches 87%
• Neck pain 67%
• Vertigo 52 %
• Visual disturbances 33%
• Paresthesia
  • Face 30%
  • Arm 33%
  • Leg 15 %

• Place the patient supine and perform passive extension and lateral flexion of the head and neck.
• Passively rotate the neck to the same side and hold for approximately 30 seconds.
• Repeat the test with a movement of the head to the opposite side.
• The test is considered positive if there is a fall in the arms, loss of balance or pronation of the hands; a positive result indicates a decrease in the blood supply to the brain.
• Other positive symptoms:
  • Dizziness
  • Tinnitus
  • Dizziness
  • Nystagmus
  • Paresthesia
  • Dysarthria
  • Diplopia
  • Dysphagia

2. Test actif de l’artère vertébrale (Dekleyn’s)

• Patient in supine position, head off the table.
• Ask the patient to hyperextend and rotate the head.
• Hold this position for 15 to 30 seconds.
• Repeat the reverse operation.

Positive test: Vertigo, dizziness, visual blurring, nausea, fainting and nystagmus. –

Structures affected: Stenosis or compression of the vertebral, basilar or carotid artery.

If the presence of BVI is evident in a patient, the practitioner should immediately discontinue provocation testing and return the patient’s neck to a neutral position (Rivett et al., 2005). Manipulation procedures should be discontinued and the patient referred to a specialist for further medical examination.

References

• W‐L Chen, C‐H Chern, Y‐L Wu, and C‐H Lee, Emerg Med J. 2006 Jan; 23(1)Vertebral artery dissection and cerebellar infarction following chiropractic manipulation
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