EDSS: Kurtzke Expanded Disability Status Scale

The EDSS is the most widely used clinical disability rating scale in multiple sclerosis research and practice. Developed by John Kurtzke in 1983, it provides a 0-10 ordinal scale capturing disease severity across eight neurological functional systems and functional status. The EDSS remains the primary endpoint in MS clinical trials and longitudinal cohort studies, with decades of prognostic and comparative data worldwide.