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.