[Retro-odontoid synovial cyst with Forestier's disease]

[Surgical management of cervical radiculopathy in Forestier's disease. Case report and review]

Forestier's disease now called DISH (diffuse idiopathic skeletal hyperostosis) is a non inflammatory enthesopathy ossifying the anterolateral spine and sparing the disc and joint space in elderly men, mostly at thoracic levels. Radiology performed for minor trauma or to explore a stiff neck provides the diagnosis. The main differential diagnosis is ankylosing spondylitis presenting an inflammatory profile as well as previously existing alterations of the sacroiliac joint. Retinoic acid treatment or ossification of the posterior longitudinal ligament should also be discussed. Dysphagia is the most frequent symptom, but neurological signs are rarely observed. We report a case observed at the cervical level. Anterior decompression and cage-fusion was indicated. Ongoing hyperostosis was also documented. Surgery in DISH is mainly indicated for dysphagia and rarely after cervical trauma. Of note are associated lesions such as OPLL (ossification of the posterior longitudinal ligament) or synovial cysts responsible for the exceptional and severe myelopathy presentation. The neurosurgical community should become better aware of Forestier's disease.