Craniocervical instability

Craniocervical instability (CCI), also known as the Syndrome of Occipitoatlantialaxial Hypermobility, is a structural instability of the craniocervical junction which may lead to deformation of the brainstem, upper spinal cord, and cerebellum. It is more common in patients with rheumatoid arthritis and Ehlers-Danlos Syndrome (itself a common co-morbidity with myalgic encephalomyelitis). CCI/AAI can occur from an injury, such as whiplash or a high-impact trauma. However, there are several known conditions where non-traumatic CCI/AAI can happen, seemingly spontaneously, for no obvious reason. This non-traumatic CCI/AAI happens with Down’s Syndrome, rheumatoid arthritis, Ehlers-Danlos Syndrome, and other inflammatory or connective tissue disorders. The ligaments of the craniocervical junction, which are made up of connective tissue, simply become too lax.

There have been anecdotal reports of people with ME who meet the International Consensus Criteria who were ultimately diagnosed with CCI and/or Chiari malformation, a related condition.

Symptoms
Symptoms of craniocervical instability include:

a heavy headache: a constant to near constant headache that can be described as feeling like the head is too heavy for the neck to support (feeling like a “bobble-head”)

a pressure headache: an impairment of CSF flow causes intracranial pressure which would be aggravated by “valsalva maneuvers” such as yawning, laughing, crying, coughing, sneezing or straining.

Dysautonomia: brainstem compression can lead to a dysfunctional autonomic nervous system (the involuntary regulator of all body functions). Symptoms of this include, but are not limited to:


 * tachycardia (rapid heart)
 * heat intolerance
 * orthostatic intolerance (low blood pressure when standing)
 * syncope (fainting)
 * polydipsia (extreme thirst)
 * delayed gastric emptying
 * chronic fatigue

Other symptoms include:


 * neck pain
 * central or mixed sleep apnea
 * facial pain or numbness
 * balance problems
 * muscle weakness
 * dizziness and vertigo
 * vision problems
 * reduced gag reflux and difficulty swallowing
 * ringing in the ears and hearing loss
 * nausea and vomiting
 * impaired coordination
 * downward nystagmus (irregular eye movements)
 * paralysis

Risk factors
Patients with Ehlers-Danlos Syndrome are at greater risk.