Painful neck on rotation: diagnostic significance for crowned dens syndrome.

The crowned dens syndrome (CDS) is a clinicoradiological entity defined as acute neck pain due to deposition of crystals surrounding the odontoid process. Crystal deposition may occur without symptoms or exhibit myelopathy by compressing the spinal cord. Neck pain on lateral rotation has been described in the previous papers for CDS. We tested the validity of "painful neck on rotation" as a potential diagnostic tool to differentiate CDS from meningeal irritation. Patients 1 and 2 were relatively young females and showed acute cervico-occipital pain, with marked limitation on neck rotation. Patient 2 was suspected to have neck strain, since there was no fever and no elevated CRP. In contrast, patient 3 was an older female and showed headache and limitation of neck rotation. Cerebrospinal fluid was normal in spite of inflammatory reaction on laboratory markers. All three patients showed absence of or only a mild limitation on neck flexion. A computed tomography scan focused on the craniocervical junction revealed mottled calcification around the odontoid process. Painful neck on rotation may have diagnostic implications for CDS in patients with cervico-occipital pain.