Multiple cerebellar infarction due to vertebral artery obstruction and bulbar symptoms associated with vertical subluxation and atlanto-occipital subluxation in ankylosing spondylitis

Ankylosing spondylitis (AS) results in disease-specific inflammation at the site of ligamentous insertion into the bone. Atlantoaxial joint subluxatio n and vertical subluxation of the axis may occur as a consequence of instab ility resulting from the inflammatory process. Spontaneous anterior atlanto axial subluxation is a well recognized complication in about 2% of patients with AS, and presents with or without signs of spinal cord compression. Ve rtical subluxation may follow anterior or posterior subluxation, It was not ed in 3-8% of patients with rheumatoid arthritis, but is an exceedingly rar e complication of AS, Moreover, it has never been reported that multiple ce rebellar infarction and bulbar symptoms developed spontaneously due to atla nto-occipital subluxation and vertical subluxation in a patient with a lung history of AS, We describe a man with AS who developed multiple cerebellar infarction due to vertebral artery obstruction and bulbar symptoms associa ted with atlanto-occipital subluxation and vertical subluxation.