Spontaneous atlanto-axial dislocation and trisomy 21: causal factors and management

Abstract

Spontaneous atlanto-axial (C1-C2) dislocation is an atlanto-axial instability, found in 10 to 30% of trisomy 21 patients, the majority of whom is asymptomatic. We report a case of a 21 years-old woman, with trisomy 21, admitted in our department presenting a spinal cord compression syndrome with right hemiparesis associated with a cervicalgia evolving for 3 months of admission without trauma. Standard cervical radiography showed a C1-C2 dislocation with posterior displacement of the odontoid process. A cervical computerized tomography revealed a C1-C2 dislocation with significant recoil of the odontoid process. A cervical magnetic resonance imaging (MRI) confirmed the bulbo-medullar junction compression on the dislocation. The surgical treatment consisted of a cervico-occipital fixation. The laxity of the transverse ligament is one of the main causes of C1-C2 dislocation; hypoplasia, malformation or complete absence of the odontoid process; are also predisposing factors. It must be early detected. The treatment of choice is surgical also by arthrodesis of C1 to C4 + graft and enlargement of the occipital foramen or occipito-cervical arthrodesis by synthetic graft and Cotrel-Dubousset system or occipito-C4 arthrodesis + laminectomy of C1 and enlargement of the occipital foramen.

Atlantoaxial subluxation and Down syndrome: A cross-sectional analysis

“…Recent studies of AAS in the DS population have been focused primarily on surgical intervention and outcomes of specific procedures. [ 6 7 8 ] Better defining the prevalence with modern data could lead to improved guide recognition, treatment, and future research in this area. Furthermore, there are currently no universally accepted guidelines for AAS treatment strategies in patients with DS versus those without, and the consistent output of literature surrounding the topic demonstrates the need for recognition and treatment of AAS in DS patients.…”