Calcium pyrophosphate dihydrate crystal deposition in the craniovertebral junction

Calcium pyrophosphate dihydrate (CPPD) deposition is a rare cause of retroodontoid mass lesions in elderly individuals. However, this condition may be severely underdiagnosed if sufficient attention is not paid to imaging characteristics and clinical presentation. The authors sought to evaluate the decision-making process in both the diagnosis and surgical treatment of CPPD.

A retrospective review of University of Iowa medical records and radiographs accumulated between 1977 and 2006 was performed. The inclusion criterion was histopathological findings consistent with pseudogout at the craniovertebral junction (CVJ). Twenty-one patients with a mean age of 70.3 years and a mean symptom duration prior to presentation of 17.5 months were identified and included in this study.

The patients presented most frequently with occipital and neck pain (85%) and numbness or paresthesias (61%). Lower cranial nerve deficits were seen in 29%. Calcification of the mass or transverse ligament was seen on computed tomography in all included patients. Gross-total resection was achieved in all patients: 19 of 21 patients underwent transoral-transpalatopharyngeal resection, with only 16 requiring concomitant dorsal occipital-cervical fusion. The mean follow-up duration was 15 months. Eighteen patients (86%) had improvement or resolution of symptoms after treatment, and 3 were lost to follow-up.

Although rare, CPPD deposition at the CVJ should be suspected on finding calcification of and around the transverse ligament on neuroimaging. Transoral-transpalatopharyngeal resection is preferred to halt the progression of neurological deterioration; dorsal fusion is not always mandatory as concomitant ligamentous calcification and atlantoaxial joint ankylosis may provide added stability.