Cervical instability can induce vertebrobasilar insufficiency (VBI), an alteration of vertebral arterial blood flow when the mobile vertebrae pinch off the artery, fostering an insufficiency of blood supply as it travels up to form the basilar artery which provides circulation to half the brain. When the upper cervical spine (C0-C2) is involved, severe associated symptoms can involve nerve irritation, headaches/migraines, dizziness, drop attacks, vertigo, difficulty swallowing and/or speaking, and auditory and visual disturbances. Symptoms of cervical instability include neck pain, muscle tension and spasms, crepitation, and paresthesias. Pain and associated symptoms can worsen in the weeks or months after an accident, as the area becomes more unstable, often leaving a person chasing the symptoms without a proper diagnosis.

The lack of a stabilizing structure can lead to further injury of the soft tissue and joint structures and the possibility of nerve injury and the irritation of the sympathetic nervous system. The ligaments of the cervical spine are particularly vulnerable to injury during a whiplash event and more notably when the head is rotated at the time of collision, such as looking in the rearview mirror. The backward hyperextension is often associated with more injury to the soft tissue, because it lacks the limiting effect of the chin meeting the chest in the forward вЂњwhip.вЂќ The excessive motion in hyperextension severely strains the involved muscles and ligaments, especially the anterior longitudinal ligament, and compresses the adjoining vertebral joints. The sudden acceleration and deceleration during rear-end collisions generate severe flexion and extension of the neck, in a whip-type motion forward and backward. Whiplash injuries are a common source of cervical instability. Cervical instability involves increased motion between adjacent vertebrae which causes excessive stress on the supporting ligamentous structures and the nerve endings within those structures eliciting pain and a variety of symptoms. Injury to the ligaments changes this dynamic, and leads to instability of the cervical spine and inadequate support for the loads placed upon it, generating changes in the vertebral alignment and creating a cycle of imbalance among the vertebral joint structures. When the cervical spine is stable, it moves and functions normally, while remaining in proper physiologic alignment and protecting the blood vessels, nerves and spinal cord. The cervical ligaments, stabilizing structures primarily responsible for connecting adjacent bones, are especially vulnerable when trauma occurs. This high degree of mobility is necessary in order to move the head through its varied range of motion. The cervical spine is unique, consisting of vertebrae that are smaller and more mobile than all of the movable vertebrae of the spine.

X ray cervical spine