Ankylosing spondylitis and multiple sclerosis in an HLA-B27 negative patient.

A 41-year-old man presented with vertigo and gait disturbance. He gave a 10-year history of definite ankylosing spondylitis with low back pain, limitation of spinal mobility, decreased chest expansion and radiological evidence of bilateral sacroiliitis. The vertigo attacks started 3 years before and he had insidious evolution of bilateral leg weakness, increased muscle tension and walking disability during the past 2 years. The HLA haplotypes of the patient were A2, A33, B14, B49, Bw4, Bw6, Cw7 and he was HLA-B27 negative. The axial and sagittal cranial magnetic resonance imaging (MRI) showed multiple foci of increased signal intensity in the periventricular white matter and cerebellar hemispheres, suggesting a demyelinating disease process. The MRI of the spine showed centromedullar high intensity lesions at C7, Th7-8, Th9-10 levels. The diagnosis was definite MS (primary progressive MS) as the patient had insidious neurological progression, CSF evidence of inthrathecal production of oligoclonal bands, conduction defects at VEP, multiple brain and additional spinal cord lesions on MRI and continued progression for more than 1 year.