Age / Sex : 84 / F

Chief complaint: Posterior neck pain for a day

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Two weeks later, you can see the final diagnosis with a brief discussion of this case.

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Courtesy: Young Hwan Lee, Daegu Catholic university Medical Center

Crowned dens syndrome

Discussion

Findings:

A Sagittal reconstruction image of C-spinal CT, shows linear calcification in transverse ligament and annulus fibrosus of C3-4 intervertebral disc. And endplate erosion of C3-4 and C6-7 vertebral bodies was noticed.

A Sagittal FS T2-weighted MR image shows soft tissue edema around the odontoid process and sagittal T1-weighted gadolinium enhanced MR image shows diffuse enhancement around the odontoid process.

Differential Diagnosis:

Crowned dens syndrome

Osteoarthritis

Rheumatoid arthritis

Gout

Diagnosis:  

Crowned dens syndrome

Discussion:

The Crowned dens syndrome was described by Bouvet et al in 1985, as neck pain caused by deposition of hydroxyapatite or CPPD crystals in the cervical spine and appearing radiographically as radioopaque densities surrounding the top and sides of the odontoid process in a crown- or halo-like distrubtion.

Crowned dens syndrome should be defined by characteristic clinical and radiographic findings. The typical clinical features of patients with crowned dens syndrome have been described as an acute onset of severe neck pain, restricted range of neck motion, and positive inflammatory indicators.

CT is the technique of choice for the detection of CPPD crystal deposition  adjacent to the odontoid process. In the cervical spine, calcified depositis in the ligamentum flavum, intervertebral disc, facet joints, lateral masses, and posterior longitudinal and atlantoccipital ligaments. Several groups have reported case series of CPPD crystal deposition of the periodontoid region, most commonly in the transverse ligament of the atlas. Additionally, there are several reports of compressive cervical myelopathy caused most commonly by CPPD deposition of the ligamentum flavum

CPPD crystal deposition in the transverse ligament can be associated with erosion of the odontoid process that may weaken the odontoid process and predispose it to subsequent fracture. This feature is interesting, because conspicuous subchondral cyst formation or bone erosion has not been reported as a dominant feature of CPPD crystal deposition disease in the peripheral joints

Wu et al. showed enhancement of the odontoid process and adjacent soft tissues by MRI. And Goto et al. also confirmed a high-signal intensity change on T2-weighted images around the dens. These findings suggest inflammation around the odontoid process

This syndrome, along with calcium crystal deposition of the cervical spine in general (including the transverse ligament of the atlas and ligamentum flavum) can mimic degenerative cervical spine disease, gout, rheumatoid arthritis and ankylosing spondylitis.

References:

1. F.Salaffi et al. The crowned dens syndrome as a cause of neck pain: clinical and computed tomography study in patients with calcium pyrophosphate dehydrate deposition disease. Clinical and experimental rheumatology 2008;26:1040-1046

2. Shinichi Goto et al. Crowned dens syndrome. Journal of bone and joint surgery. 2007;89:2732-6

3. Chang et al. Frequency of atlantoaxial calcium pyrophosphate dehydrate deposition at CT. Radiology. 2013;269:519-524

4. Wu et al. The crowned dens syndrome as a cause of neck pain : report of two new cases and review of the literature. Arthritis & Rheumatism. 2005;53:133-137