Vertigo and Dizziness

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Cervical Vertigo

Cervical Vertigo, also known as cervicogenic vertigo or cervicogenic dizziness is a controversial entity. There is evidence that it is a distinct disorder but there is no agreed upon pathophysiology, reliable test, or diagnostic criteria. Reliable and well established tests support an alternative diagnosis in almost all patients with vertigo. In centres with advanced capabilities for assessing vertigo, cervical vertigo probably makes up about 1% of all cases. However, in settings of whiplash, post-traumatic dizziness is very common.

All clinical studies on the condition have three major weak points: inability to confirm the diagnosis, no specific laboratory test, and unexplained discrepancy between those with severe neck pain with no vertigo and those with moderate neck pain with severe vertigo.

Cervical facet joints densely innervated, 50% of all cervical proprioceptors in joint capsules C1-C3. Dense mechanoreceptors in gamma-muscle spindles of deep segmental upper cervical muscles Direct connections to vestibular and visual systems. Mechanoreceptor function can be altered by pain, trauma, fatigue, degeneration.

The vestibulospinal tract is a descending motor pathway (extrapyramidal) that gives motor commands that control posture. The medial tract is for neck muscles, head stabilisation / coordination, and eye movement. The lateral tract is for antigravity muscles, the leg extensors for upright posture. The vestibulospinal reflex helps maintain balance, posture, and stability. There is no objective test for detecting deficient or excessive vestibulospinal activity. An example:

• Sensory: Head tilted to one side, stimulates vestibular canals and otoliths
• Afferent: vestibular nerve and nucleus stimulation
• Efferent: lateral and medial vestibulospinal tracts
• Result: Movement opposed that which is registered by the vestibular system (Extensor effects in muscles on side of neck to which it is bent, and flexor effects in muscles on opposite side)

There are multiple models of cervical dizziness. Abnormal sensory input from neck, cervical cord abutment, or high cervical disease, vertebral artery compromise (Bow Hunters syndrome), sympathetic dysfunction (Barre-Lieou syndrome), Cervicogenic migraine, CSF leak, neck interaction with other types of vertigo, and inner ear damage associated with neck injury.

Abnormal Sensory Input

In whiplash there may be damage to tonic neck reflexes, secondary to pain. When the neck is activated, cervical input is dominant over vestibular, so possibly cervical vertigo could occur in this manner due pain or stiffness (Magnusen 2006). There is indirect evidence of abnormal sensory inputs in cervical dizziness. There have been experiments causing balance disturbance - noxious stimulation of posterior neck muscles, and local anaesthetic to upper cervical nerves. There is possibly spinovestibular pathway dysfunction in these experiments. Whiplash leads to deficits in neck position sense, and there may be relief of vertigo with a medial branch block in whiplash. Manual therapy seems to be effective. There is often a disturbance in vestibulospinal control of optokinetic pursuit: Eye pursuit normal with static head, abnormal with head rotation.

“…cervical vertigo results from altered somatosensory input into the vestibular nuclei from the proprioceptors of the upper cervical region…[there is a] sensory mismatch between vestibular and cervical inputs”

The neural mismatch model describes a mismatch between expected and actual neck movement From neck pain/stiffness, inducing motion sickness.

Migraine Associated Cervicogenic Vertigo

Vestibular migraine is the second most common cause of vertigo after BPPV. Migraine could be a link between cervical pain and vertigo through connections between the vestibular and trigeminal nuclei.

Assessment

History

• Pain in back of neck, radiates temporo-parietally, may only be present with palpation
• Symptoms worse with neck pain and neck movement
• Symptoms better with interventions that relieve neck pain
• Vertigo lasts minutes to hours
• History of neck injury

Examination

• Reproducible vertigo with neck manipulation
• Tender suboccipitally, C1 and C2 transverse processes
• Tender C2 and C3 spinous processes
• Tender myofascial structures
• Upper C-spine range of motion
• No definitive diagnostic test

Treatment

Both Mulligan (in the form of cervical SNAGs) and Maitland mobilisations appear to be beneficial.