(906) Atlanto-Occipital Dissociation in an 11-Month-Old After a Motor Vehicle Accident

Introduction: Atlanto-occipital dissociation (AOD) is the disruption of the ligamentous or bony structures connecting the cranial base to the cervical vertebrae. AOD can be subtle and missed in trauma-related injuries. However, AOD is associated with cervical spinal cord and brainstem injuries resulting in significant morbidity and mortality. Recognition of AOD has increased due to improved trauma resuscitative techniques and advanced imaging. This case demonstrates the early recognition and management of AOD in an 11-month-old.

Description: An 11-month-old female presented as a trauma arrest after ejection from a multivehicle accident. After several rounds of cardiopulmonary resuscitation, return of spontaneous circulation was achieved. Secondary survey revealed forehead hematoma, minimally reactive pupils, maintenance of blinking, biting, and minimal cranial nerve XI activity, with no spontaneous movement of bilateral upper or lower extremities, and no other outward traumatic injuries. The infant underwent computed tomography (CT) scan, which showed AOD with hemorrhage through the anterior and posterior longitudinal ligaments. She was maintained in strict C-spine precautions, but developed neurogenic shock, respiratory failure, and quadriplegia. After stabilization, she underwent immobilization in a halo vest, tracheostomy and gastrostomy tube placement and mechanical ventilation. After bony callus formation and apparent stability of her atlanto-occipital joint, the halo was removed and a hard cervical collar was placed. She was discharged to a long-term rehabilitation facility.

Discussion: Children are more prone to AOD because of lax atlanto-occipital ligaments, larger skull relative to spine, and more horizontal orientation of the atlanto-occipital joint. Clinical findings include severe neurologic, cardiac and respiratory failure due to spinal cord and brainstem injuries. Diagnosis is aided by lateral cervical spine plain-film radiographs, but is best seen with CT or magnetic resonance imaging. Management includes cervical spine stabilization with halo placement and/or occipito-cervical fusion.