Gregory J. Przybylski, MD, Chicago, IL, USA; Brent Clyde, MD, Charles Fitz, MD, Pittsburgh, PA, USA; William Mitchell, MD, Philadelphia, PA, USA; Denise Lemke, RN, David Daniels, MD, Milwaukee, WI, USAPurpose: Atlanto-occipital dislocation (AOD) was formerly considered an unusual and often fatal injury. Although rapid resuscitation has resulted in more frequent early survival, failure to recognize AOD and quickly institute appropriate treatment often results in neurological worsening. Moreover, the infrequency of this injury limits conclusions regarding management based on individual experience. This multicenter study evaluates the diagnosis and management of patients in a comparatively large series of patients with AOD.Methods: Between 1980 and 1998, 30 patients with AOD were identified at four medical centers. Patients were identified by searching diagnoses on discharge records and radiological reports. Hospital, office and radiographic records were reviewed. Follow-up was obtained by office evaluation as well as by phone calls.Results: Twelve patients died within 2 weeks of their injury. Seven were children, and seven were female. Most had type 2 dislocations. All sustained a cardiopulmonary arrest at the scene. Only three regained purposeful movement before dying from either concurrent supratentorial injuries (n=2) or sepsis (n=1). All but one had craniocervical subarachnoid hemorrhage demonstrated on computed tomography (CT) imaging or at autopsy. Eighteen patients survived beyond the first month with a median follow-up of 1 year. Nine were children, and 11 were male. Only one had a type 3 dislocation, whereas nine had type 1 dislocations. Only seven were diagnosed on the initial plain lateral radiograph, whereas five others could have been diagnosed on the original radiograph but were missed. The remaining six required additional imaging (CT or magnetic resonance imaging) for diagnosis. Sixteen patients had either craniocervical subarachnoid hemorrhage (n=15) or a brainstem contusion (n=1). Six patients were neurologically intact, three had minor deficits (cranial nerve or monoparesis) and nine had severe deficits (hemiplegia, quadriparesis or quadriplegia). Of eight patients (six children and two adults) treated initially with external immobilization alone, two (one child and one adult) required fusion after 4 months for persistent instability. One normal patient with an initially unrecognized type 1 dislocation developed quadriparesis after traction. Two patients were treated with early fusion; quadriplegia remained in one, and quadriparesis resolved in the other. Two of the remaining eight patients initially immobilized and then treated with a delayed fusion developed new deficits postoperatively; one normal patient had a tenth cranial nerve deficit, whereas a severely quadriparetic woman became quadriplegic. All but one quadriplegic patient remained quadriplegic.Discussion: Survival after AOD has become more frequent. The diagnosis is frequently missed on initial plain lateral radiographs. The presence of subarachnoid hemorrhage at the craniocervical junction should increase the index of suspicion for AOD. Traction occasionally causes new neurological deficits. Although some patients have been successfully treated without fusion, development of subsequent neurological deficits or failure to achieve stability is often observed. Prompt recognition and early craniocervical fusion may improve neurological recovery in survivors of this unusual injury.