The crowned dens syndrome as a cause of neck pain: clinical and computed tomography study in patients with calcium pyrophosphate dihydrate deposition disease.

OBJECTIVE: To investigate the association between articular chondrocalcinosis and calcification of the atlantoaxial region on a cervical computed tomography (CT) scan and to explore the relation between such calcifications and neck pain.

MATERIALS AND METHODS: CT slices of the cervico-occipital junction were performed routinely in 49 consecutive patients (male/female ratio 28/21; mean age 70.4 yrs), diagnosed with calcium pyrophosphate dihydrate crystal deposition disease (CPPD). Of these, 35 met criteria for definite CPPD and 14 met the criteria for probable. The cervical CT scans were analyzed for the presence of periodontoid calcifications by 2 independent musculoskeletal radiologists. Both assessors were blinded to the disease status of the patients. Furthermore, conventional radiographs of the upper cervical spine were performed. An ad hoc designed protocol was used to register information at diagnosis, including age, sex, location of pain and stiffness, fever, presence of synovitis and its location.

RESULTS: CT scan of the cervico-occipital junction showed periodontoid calcified deposits in 25 out of 49 patients (51%) with CPPD. In 10 of the 25 cases (40%) with periodontoid calcified deposits, CT scanning showed osseous abnormalities of the odontoid process, such as subchondral cysts or erosions. Conventional radiographs showed calcification behind the odontoid process in 17 patients (34.7%). Nine of CPPD cases (18.4%) presented with neck symptoms. In three patients, articular chondrocalcinosis was revealed only by an acute attack of neck pain with segmentary stiffness, fever, and an increased erythrocyte sedimentation rate; in one of them initial clinical examination found cervical stiffness with Kernig's and/or Brudzinski's sign. For the other two patients, impairment of general condition, occipito-temporal and mandible pain and weakness with inflammatory pain of the shoulder girdle was suggestive of giant cell arteritis (GCA) and/or polymyalgia rheumatica (PMR). In the six additional patients, questioning elicited a history of previous subacute or chronic neck pain, from one week to one year before their admission to our ambulatory or hospital.

CONCLUSIONS: These results suggest that CPPD deposition disease frequently involves the cervical spine. Although such calcification often remains asymptomatic, it may be associated with attacks of acute neck pain with segmentary stiffness, fever, and an increased erythrocyte sedimentation rate, sometimes mimicking PMR and/or GCA or neurological symptoms.