Our experiences in patients with atlanto-occipital dislocation: A case series with literature review

Atlanto-occipital dislocation (AOD) is an injury to the upper cervical spine that occurs after trauma. This injury is associated with a high mortality rate. According to studies, 8%-31% of deaths caused by accidents are due to AOD. Due to the improvement in medical care and diagnosis, the rate of related mortality has decreased. Five patients with AOD were evaluated. Two cases had type 1, one case had type 2, and two other patients had type 3 AOD. All patients had weakness in the upper and lower limbs and underwent surgery to fix the occipitocervical junction. Other complications in patients were hydrocephalus, 6 nerve palsy, and cerebellar infarction. All patients improved in follow-up examinations. AOD damage is divided into four groups: anterior, vertical, posterior, and lateral. The most common type of AOD is type 1 and the most instability is type 2. There are neurological and vascular injuries due to pressure on regional components; vascular injuries are associated with high mortality rate. In most patients, their symptoms improved after surgery. AOD requires early diagnosis and immobilization of the cervical spine along with maintaining the airway to save the patient's life. It is necessary to consider AOD in cases with neurological deficits or loss of consciousness in the emergency unit because earlier diagnosis could cause a wonderful improvement of the patient's prognosis.