Atlantoaxial rotatory dislocation with hypoglossal nerve palsy in a patient with ankylosing spondylitis. A case report.

tlantoaxial subluxation is a rare but well-recognized complication of ankylosing spondylitis. Anterior subluxation is most common, but vertical subluxation of the dens may also occur and may result in cervical myelopathy, lower cranial nerve palsy, or even sudden death due to cervicomedullary compression. Tongue paralysis due to isolated hypoglossal nerve palsy is also rare. In addition to occurring in patients with rheumatoid arthritis, hypoglossal nerve palsy has been noted in association with a number of pathological conditions such as occipital condylar fracture, metastatic tumor in the skull base, and infection. We report on a patient with ankylosing spondylitis who presented with life-threatening atlantoaxial rotatory dislocation and bilateral hypoglossal nerve palsy and was successfully treated with halo-dependent traction followed by occipitocervical arthrodesis. To the best of our knowledge, bilateral hypoglossal nerve palsy with tongue paralysis arising from atlantoaxial rotatory dislocation has never been reported in a patient with ankylosing spondylitis. The patient consented to have the data concerning the case submitted for publication.