Crowned dens syndrome resembling meningitis as the first manifestation of calcium crystal deposition disease.

Crowned dens syndrome (CDS) is a rare disease characterized by acute neck pain due to deposition of calcium pyrophosphate dihydrate (CPPD) or calcium hydroxyapatite (HA) crystals surrounding the odontoid process.1 Herein, a case of CDS mimicking meningitis as the first manifestation of calcium crystal deposition disease is presented. A course of corticosteroid therapy eradicated all clinical symptoms within a few days. A 67-year-old woman was admitted to the emergency department for neck pain and fever. Her past medical history included obesity and hypertension, and she had a subtotal thyroidectomy for giant multinodular goiter, requiring treatment with l-thyroxine on a regular basis since then. In the emergency department, she complained of neck pain and occipitalgia, with marked restriction of cervical movement. She had been previously treated with nonsteroidal anti-inflammatory drugs (NSAIDs) without improvement. Physical examination revealed fever, rigidity of the neck, and positive Kernig's sign. Cardiopulmonary and abdominal examinations were normal. Full blood cell count revealed 16,700 leukocytes/mL with 85% neutrophils. Erythrocyte sedimentation rate (ESR) was 78 mm in the first hour, and C-reactive protein (CRP) was 107 mg/L (normal < 5). Laboratory parameters including hepatic and renal function and coagulation tests were normal. Plain radiographs of the cervical spine showed cervical spondylosis. Infectious meningitis was suspected and excluded according to computed tomography (CT) of brain and lumbar puncture that showed normal findings. CT and magnetic resonance imaging (MRI) of the cervical spine excluded discitis. Upon close inspection of X-ray and CT, densities in the odontoid process area and a periodontoid calcification were identified (Figure 1 A and B). Taking everything into consideration, a diagnosis of CDS was made. No radiological evidence of coexisting CPPD deposition within primary sites, such as knees, wrists, and pubis, was found. Despite undergoing treatment with l-thyroxine, an extensive evaluation was performed to exclude any other metabolic conditions. A course of corticosteroid treatment provided prompt symptomatic relief. CDS is generally found in older adults known to have pseudogout.1-3 This 67-year-old woman had CDS as the first manifestation of CPPD deposition. Although neurological complications are rare, spinal stenosis or cervical myelopathy can be found.3 As in the current case, meningitis must be excluded. In addition to meningitis, discitis, degenerative cervical spine disease, temporal arteritis, polymyalgia rheumatica, metastatic bone disease, and spinal tumors may mimic CDS.4 Patients typically present with severe neck pain and marked restriction of cervical rotation.5 ESR and CRP are often high. X-ray examinations may show densities in the process area but most often are normal. CT scanning focusing on C1/C2 is the criterion standard diagnostic test. Histological or microscopic examination of crystals is not required. Cervical MRI is generally unhelpful in diagnosing this disease, although it may be used to exclude important differentials, such as discitis, malignancy, and myelopathy.3, 6 NSAIDs is the criterion standard treatment, although in the present case, NSAIDs were found to be insufficient, and a medium dose of corticosteroids was needed. The reason for this remains unclear, and a variable degree of severities have been suggested as a cause.7 Therefore, corticosteroid therapy can be used in severe cases. CDS is a rare and underrecognized disease. It is important for clinicians to recognize this syndrome as a potential cause of acute neck pain mimicking infectious meningitis. The rapid diagnosis of CDS can avoid invasive, expensive, and useless procedures and potentially dangerous treatments or prolonged hospitalization in older adults. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: All authors meet the criteria for authorship stated in the Uniform Requirements for Manuscripts Submitted to Biomedical Journals. Sponsor's Role: The authors declare that they have no sponsors.