Crowned Dens Syndrome Associated with Bowel Cleaning for Colonoscopy.

A 77-year-old man was admitted with posterior cervical pain, lumbago, a low-grade fever, and anorexia after bowel cleaning with polyethylene glycol for colonoscopy. Computed tomography of the neck showed calcification of the transverse ligament of the atlas. He was diagnosed with crowned dens syndrome (CDS). His condition improved following treatment with corticosteroids. This represents a rare case of CDS after endoscopy with polypectomy. We should consider CDS in the differential diagnosis of patients with unexplained fever and posterior cervical pain after bowel preparation for colonoscopy.