Traumatic retropharyngeal pseudomeningocele with atlanto-occipital dislocation in a neurologically intact patient.

Traumatic retropharyngeal pseudomeningoceles occur rarely, are associated with severe trauma, and have been reported in patients with significant neurologic deficits at presentation. We report the rare occurrence of a pseudomeningocele following a high-speed motor vehicle accident. Neurological examination showed the patient to be briskly following commands, with intact cranial nerve, motor, and sensory function. CT/MR imaging showed subarachnoid hemorrhage involving the interpeduncular cistern, a clivus fracture, a right occipital condyle fracture, an atlanto-occipital subluxation, aortic arch transection (stable and contained on CT angiogram), multiple rib fractures on the right side with associated pneumothorax, hemothorax and pulmonary contusions. His cervical spine was stabilized in a halo. He was subsequently managed in the intensive care unit and remained neurologically intact. A repeat MRI showed the interval development of a 2×1.5 cm pseudomeningocele at the craniocervical junction medial to the left occipital condyle communicating with the left anterolateral aspect of the spinal canal. Traumatic pseudomeningoceles are associated with large deceleration forces at the time of injury and are usually associated with significant neurologic deficits at presentation. However, they can arise and give rise to symptoms in a delayed fashion in trauma patients who are neurologically intact at initial presentation.