Can Dissemination in Space Alone Diagnose Multiple Sclerosis?

The 2017 McDonald criteria for multiple sclerosis (MS) diagnosis require dissemination in space (DIS) and time (DIT), or cerebrospinal fluid (CSF)-specific oligoclonal bands as a substitute for DIT. To assess whether extensive DIS alone could reliably predict MS diagnosis, researchers prospectively followed 244 patients with a first demyelinating event for a mean of 11.2 years.

DIS involving all four CNS regions classically affected in MS (periventricular, juxtacortical, infratentorial, spinal cord) had 100% specificity and positive predictive value for MS diagnosis, although sensitivity was modest (26%). Including the optic nerve as a fifth region improved sensitivity to 30% while maintaining 100% specificity.