Post-Traumatic Longitudinal Atlanto-Occipital Dissociation without Neurodeficits Treated with Visor (Head-Neck-Chest ) Orthosis - a Rare Case Report and Review of the Literature.

Introduction: Death is the most common outcome of longitudinal atlanto-occipital dissociation (L-AOD). Even though rare, survival is commonly seen in the pediatric population. This study reports a successful outcome of a pediatric patient with an L-AOD without neurodeficits, immobilized in a visor (head-neck-chest) orthosis.

Case report: A 9-year-old boy came off his motorbike during a jump at ~50 kph. He was transferred from the primary hospital with spine precautions and a cervical collar with multiple injuries with neurologically intact on presentation. The computed tomography (CT) spine demonstrated a widening of the basion-dens interval, estimated approximately at 16 mm (normal <10 mm), with the widening of the atlanto-occipital articulations with occipital condyles and atlas facet distance markedly widened approximately at 7 mm (normal <5 mm). Considering intact neurology and no complete tear of the tectorial membrane, the decision was made to immobilize in a visor (head-neck-chest) orthosis for controlled vertical cranial settling to occur. Periodic cervical spine imaging over 3 months was done to assess the reduction. At the end of 3 months, dynamic cervical spine X-rays and CT scans confirmed atlanto-occipital articulations with the basion-dens interval and intercondylar distance within normal limits.

Conclusion: L-AOD is a rare diagnosis with a high rate of neurological deficits and mortality. The advancements in emergency care, diagnostic methods, and treatment options have increased survival rates and overall prognosis of the atlanto-occipital dissociation. A visor (head-neck-chest) orthosis and careful observation could be one of the treatment options for L-AOD.