Working Diagnosis:
Concussion with episodes of transient quadriplegia and ongoing atlantoaxial instability due os odontoideum

Treatment:
Patient underwent C1-2 posterior instrumented fusion with an iliac crest allograft approximately 2 months after injury. Case Photo #4

Outcome:
Patient's concussion symptoms resolved, and he recovered well from surgery. He was cleared for non-contact activities, but was told to avoid organized and contact sports.
Of note, the patient was referred to sports psychology when the referral to neurosurgery was submitted. During his hospitalization, he was also noted to have suicidal ideation with intention to act upon his plan of suicide. He was evaluated by behavioral health and was eventually cleared for discharge home with close outpatient follow-up. Patient was eventually started on Sertraline. He continues to follow with outpatient psychology, psychiatry, and sports psychology.

Author's Comments:
Os odontoideum is a rare anatomic anomaly with unknown prevalence and etiologies that are widely debated. It is commonly diagnosed incidentally and often presents without clinical symptoms. Diagnosis can be obtained with plain X-ray. However, MRI and CT scanning are recommended for further clarification and judgment of the severity. Case Photo #5 Careful history taking and physical exam is critical as they may reveal a history of nondescript cervical or occipital pain, transient neurologic symptoms, or mild progressive neurologic compromise. The presence of atlantoaxial instability or neurological symptoms or dysfunction necessitates surgical intervention with instrumentation and fusion for stability to avoid potentially catastrophic injuries.

Owing to the rarity of the disease, variable clinical presentations, and high morbidity secondary to atlantoaxial instability; a high index of suspicion for os odontoideum is important to minimize misjudgment, misdiagnosis, and consequently inappropriate treatment. If this entity is encountered, it is recommended that patients are examined by highly specialized spine doctors before further contact sport participation, high risk activities, or cervical manipulation due to the high risk of instability with potentially severe consequences.

Editor's Comments:
This case emphasizes two very important considerations. The clinician should always take a thorough history. While this case could have seemed like a straight-forward concussion, eliciting the transient quadriplegia event was critical in making the diagnosis. The clinician should always review previous images or retake them if not available. In this case, assuming the previous cervical spine films were complete and normal would have likely resulted in missing the diagnosis.

References:
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