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.