The true incidence of cervical artery dissection is difficult to determine. Most spontaneous CADs result from a sub-adventitial tear caused by haemorrhage in the tunica media or tunica adventitia
CAD is the most catastrophic adverse event associated with cervical manipulative therapy. Cervical manipulation is one potential form of minor trauma, but the trauma can have various origins including sporting or recreational activities. Common to these activities is some degree of rotation or hyperextension of the neck or increased intra-thoracic pressure e.g. from lifting or paroxysmal coughing.