Up to 15% of children with Down syndrome have atlanto-axial instability (AAI) due to constitutional ligament hyperlaxity. Symptomatic disease occurs in 3% of patients: most frequently neurological symptoms of spinal cord compression slowly progress over time but complications from vertebral dislocation can manifest with sudden painful torticollis. While asymptomatic cases require no intervention, symptomatic cases are at risk for irreversible neurological damage and require prompt recognition and surgical stabilization of cervical spine. The paper describes the case of a 10-year-old girl with Down syndrome and AAI who presented with painful torticollis caused by rotatory dislocation of C1-C2. Torticollis was initially misdiagnosed as myogenic. Vertebral dislocation was recognized one month after the onset of symptoms and appropriately managed with surgical stabilization of cervical spine.
