Crowned dens syndrome
Crowned dens syndrome can cause acute neck pain due to calcifications surrounding the odontoid process. These calcifications are frequently a combination of BCP and especially CPPD crystals. This condition occurs most commonly in the elderly and can cause fever and associated neurologic symptoms including headache, confusion, and aseptic meningitis. Calcifications are seen best on an open-mouth view of the odontoid process or a computed tomography scan of the area.