Expanded Disability Status Scale (EDSS)


The Expanded Disability Status Scale (EDSS) is a method of calculating and understanding disability in multiple sclerosis patients as well as monitoring changes of disability over time. EDSS is widely used in research clinical trials and studies in assessing people with MS.

Developed by a neurologist named John Kurtzke in 1983 as an advancement of his previous 10 step Disability Status Scale (DSS).

EDSS  measures ranges from 0 to 10 in 0.5 unit increments that represent increased levels of disability. The scoring is based on an examination by a neurologist but is also useful for you to measure where your disease may currently be in as far as the progression scale indicates.

EDSS steps 1.0 to 4.5 refer to people with MS who are able to walk without any aids and measures impairment in eight functional areas:

  • pyramidal – weakness or difficulty moving limbs
  • cerebellar – loss of full control of bodily movements, loss of coordination or tremor
  • brainstem – problems with speech, swallowing and nystagmus ( involuntary or voluntary, in rare cases eye movement)
  • sensory – numbness or loss of sensations
  • bowel and bladder function
  • visual function
  • cerebral (or mental) functions
  • other
EDSS Chart Image
EDSS Chart Click For Larger Image

Each functional aspect is scored on a scale of 0 (no disability) to 5 or 6 (more severe disability).

EDSS steps 5.0 to 9.5 are defined by the impairment to walking. The scale is sometimes criticized for its reliance on walking as the main measure of disability.

Although the scale takes account of the disability associated with advanced MS, most people will never reach these scores. A large study that looked at people with MS at a clinic in Ontario (prior to the development of the expanded version) found that 51% of people had a DSS score of 5 or lower. 88% had a score of 7 or lower.

Thus a new scale of disability really needs to be created.

It is IMPORTANT to understand that. The EDSS scale is not a defacto mechanism but instead a fairly simplistic means and mechanism to measure MS disability rather broadband.

It is somewhat amazing that this facet of MS has not been further addressed these days with a more comprehensive system.

Expanded Disability Status Scale (EDSS)

Score Description
1.0 No disability, minimal signs in one Function System
1.5 No disability, minimal signs in more than one Function System
2.0 Minimal disability in one Function System
2.5 Mild disability in one Function System or minimal disability in two Function Systems
3.0 Moderate disability in one Function System, or mild disability in three or four Function Systems. No impairment to walking
3.5 Moderate disability in one Function System and more than minimal disability in several others. No impairment to walking
4.0 Significant disability but self-sufficient and up and about some 12 hours a day. Able to walk without aid or rest for 500m
4.5 Significant disability but up and about much of the day, able to work a full day, may otherwise have some limitation of full activity or require minimal assistance. Able to walk without aid or rest for 300m
5.0 Disability severe enough to impair full daily activities and ability to work a full day without special provisions. Able to walk without aid or rest for 200m
5.5 Disability severe enough to preclude full daily activities. Able to walk without aid or rest for 100m
6.0 Requires a walking aid – cane, crutch, etc – to walk about 100m with or without resting
6.5 Requires two walking aids – pair of canes, crutches, etc – to walk about 20m without resting
7.0 Unable to walk beyond approximately 5m even with aid. Essentially restricted to wheelchair; though wheels self in standard wheelchair and transfers alone. Up and about in wheelchair some 12 hours a day
7.5 Unable to take more than a few steps. Restricted to wheelchair and may need aid in transferring. Can wheel self but can not carry on in standard wheelchair for a full day and may require a motorized wheelchair
8.0 Essentially restricted to bed or chair or pushed in wheelchair. May be out of bed itself much of the day. Retains many self-care functions. Generally has effective use of arms
8.5 Essentially restricted to bed much of day. Has some effective use of arms retains some self care functions
9.0 Confined to bed. Can still communicate and eat
9.5 Confined to bed and totally dependent. Unable to communicate effectively or eat/swallow
10.0 Death due to MS