Craniocervical instability (CCI) is a medical condition where there is excessive movement of the vertebrae at the atlanto-occipital joint and the atlanto-axial joint, that is, between the skull and the top two vertebrae. The impact of craniocervical instability can range from minor symptoms to severe disability, with some patients being bed-bound. The constellation of symptoms caused by craniocervical instability has been labelled the cervico-medullary syndrome. Common symptoms include:
- Occipital headaches
- Migraine headaches
- Neck, shoulder, and jaw pain
- Difficulty swallowing, or the sensation of being choked
- Tenderness at the base of the skull
- Feeling of bobble-head', where the skull may 'fall off' the spine
Craniocervical instability is usually diagnosed through neuro-anatomical measurement using radiography. Digital Motion X-ray is considered the most accurate method. Upright magnetic resonance imaging, supine magnetic resonance imaging, CT scan, and flexion and extension x-rays may also be used. Other symptoms reported in patients with CCI include tachycardia, heat intolerance, orthostatic intolerance, syncope, numbness, motor weakness, dizziness, and gait instability. The level of disability is important in diagnosing craniocervical instability (CCI) .