Expanded Disability Status Scale (EDSS) Calculator

How does this Expanded Disability Status Scale (EDSS) calculator work?

This is a health tool based on the scale developed by John Kurtzke in 1983 as part of the neurologic research he’s been conducting at the time.

The EDSS is often use to monitor the level of disability in MS over time and the scale can be reapplied after a period of time. As a practice, it is applied by either a neurologist or a trained nurse practitioner and usually takes around 15 to 45 minutes due to the component that assesses walking distance.

Several clinical trials have had this MS scale a subject in the assessment of patients and the categorization of neurological severity.

One of the main criticism received by the scale refers to its big reliability in walking as a parameter to evaluate disability and on which to count the rest of dysfunctionalities. Despite that, it continues to be a preferred tool in the neuro examinations and as a recognition of its merits has been included in the Minimal Record of Disability by the World Health Organization.

EDSS scale interpretation

The scale ranges from 0, attributed to normal neurological examination results to 10, attributed to death due to MS; with a 0.5 unit increment therefore there are 20 items that describe the different levels.

Items from 0 to 4.5 display a minimal to mild level of disability, i.e. patients who are able to walk without aid and as well benefit from ambulatory treatment. It also makes reference to the eight functional systems (FS) in the standard neurological examination and the level of disability triggered by impairment in either of them:

■ Cerebral functions;

■ Visual function;

■ Sensory;

■ Brainstem;

■ Bowel, bladder function;

■ Cerebellar;

■ Pyramidal;

■ Other.

Items from 5.0 to 9.5 are characterized by levels of impairment to walking and that of ambulation.

Items in the lower end tend to be more dependent on the subjectivity and clinical judgment of the neurological examination, the middle range focuses on both impairment and disability while the upper end exhibits patients who are dependent of every day assistance.

Multiple sclerosis general guidelines

MS is a condition of the central nervous system in which the myelin, the coating layer of the nerves becomes increasingly damaged due to an altered immune system response. Symptoms usually first occur around 20s and 30s and depending on how quick and efficient the treatment is, tend to progress in different ways.

Multiple sclerosis progression is a highly specific disease advancement as it can take different shapes and progress in different degrees of severity. This is why tools like EDSS are used to evaluate more than signs and symptoms and to put together the whole range of experiences and disability someone with MS goes through.

Symptoms usually depend on which part of the central nervous system is most affected and of the function impaired by the damage to the specific nerves. Most common include vision problems, fatigue, balance, dizziness and spasms.

Available therapies nowadays include disease modifying therapies with drugs specially created to address the transformations in MS which can reduce the severity of symptoms and slow down nerve destruction. Alongside, alternative therapies, exercise and diets might reduce the discomfort.

References

1) Kurtzke JF. (1983) Rating neurologic impairment in multiple sclerosis: an expanded disability status scale (EDSS). Neurology; 33(11):1444-52.

2) Weinshenker BG, Bass B, Rice GP, Noseworthy J, Carriere W, Baskerville J, Ebers GC. (1989) The natural history of multiple sclerosis: a geographically based study. I. Clinical course and disability. Brain; 112 ( Pt 1):133-46.

3) Lublin FD, Reingold SC. (1996) Defining the clinical course of multiple sclerosis: results of an international survey. National Multiple Sclerosis Society (USA) Advisory Committee on Clinical Trials of New Agents in Multiple Sclerosis. Neurology; 46(4):907-11.