EDSS and Outcomes Measurement in MS

Regina Berkovich, MD, PhD: EDSS, or Expanded Disability Status Scale, which is used for an assessment of the level of disability in multiple sclerosis [MS], has been used for years. In fact, the predecessor of this scale was used for the very first multicenter study in multiple sclerosis, which was published back in 1970. Ever since then, we seem to continue to use a very similar scale called EDSS, or the Kurtzke scale, which basically assesses the functionality and level of disability of MS patients, mostly based on their ambulatory status. That is unfortunate because obviously walking is not what makes us humans. However, it’s an important function, and I think that the use of EDSS reflects our society, which may be judging individuals based on their physical performance more than their, for example, cognitive performance.

But I would like to point out that the most common reason for disability in young adults with multiple sclerosis is cognitive disability. That, unfortunately, is not being captured that well by the EDSS. So, it’s a scale that has been classic, has been in use for many years, and has its own limitations. But we still continue using it because we don’t have anything better.

Clinical trials being conducted for the long-term or disease-modifying therapy in multiple sclerosis involve several classical outcome measures such as analyzed relapse rate, EDSS scores or changes on EDSS scores, and radiologic or imaging MRI [magnetic resonance imaging] outcomes, which could reveal new lesions, newly enlarged lesions, and active gadolinium-enhancing lesions. Some of the studies also involve some MRI measures such as the T1 black holes and volumetric studies as well. We are getting more sophisticated when it comes to the paraclinical evaluation such as MRI, and this is very good because MRI metrics are the most objective. They are the only reliable biomarker we currently have. It is used for both diagnosis of multiple sclerosis and as an outcome measure, helping us understand whether the patient is responding to the disease-modifying therapy.