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 Ehlers-Danlos Syndrome (itself a common co-morbidity with myalgic encephalomyelitis).

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.