The main scale used is the The Expanded Disability Status Scale (EDSS) which was developed by Kurtzke in 1983 and measures Neurological impairment (or the damage to the functioning of the brain) in people with MS.
The EDSS score is generated following a Neurological examination carried out by a Neurologist. When generating an EDSS score, the Neurologist will use Functional System Scores. The Functional Systems (FS), of which there are 7, relate to various functions of the Central Nervous System such as visual functions and sensory functions. Following the examination, a score can be given for each Functional System ranging from 0 to 5 or 6 depending on the Functional System being examined. The scores are sometimes called grades. A grade of 0 (zero) relates to normal Function in the system. The higher the grade, the more problems have been detected in that Functional System.
Once a grade has been given for each Functional System the results are used,
along with other information gained from the examination, to generate the
EDSS score.
Rating neurologic impairment in multiple sclerosis (Kurtzke, 1983)
Functional Systems (FS)
Pyramidal Functions
0. Normal.
1. Abnormal signs without disability.
2. Minimal disability.
3. Mild or moderate paraparesis or hemiparesis;
severe monoparesis.
4. Marked paraparesis or hemiparesis; moderate quadriparesis;
or monoplegia.
5. Paraplegia, hemiplegia,
or marked quadriparesis.
6. Quadriplegia.
V. Unknown.
Cerebellar Functions
0. Normal.
1. Abnormal signs without disability.
2. Mild ataxia.
3. Moderate truncal or limb ataxia.
4. Severe ataxia, all limbs.
5. Unable to perform coordinated movements due to ataxia.
V. Unknown.
X. Is used throughout after each number when weakness (grade 3 or more on
pyramidal) interferes with testing.
Brain Stem Functions
0. Normal.
1. Signs only.
2. Moderate nystagmus or other mild disability.
3. Severe nystagmus, marked extraocular weakness or moderate disability of
other cranial nerves.
4. Marked dysarthria or other marked disability.
5. Inability to swallow or speak.
V. Unknown.
Sensory Functions (revised 1982)
0. Normal.
1. Vibration or figure-writing decrease only, in one or two limbs.
2. Mild decrease in touch or pain or position sense, and/or moderate decrease
in vibration in one or two limbs; or vibratory (c/s figure writing) decrease
alone in three or four limbs.
3. Moderate decrease in touch or pain or position sense, and/or essentially
lost vibration in one or two limbs; or mild decrease in touch or pain and/or
moderate decrease in all proprioceptive tests
in three or four limbs.
4. Marked decrease in touch or pain or loss of proprioception, alone or combined,
in one or two limbs; or moderate decrease in touch or pain and/or severe proprioceptive
decrease in more than two limbs.
5. Loss (essentially) of sensation in one or two limbs; or moderate decrease
in touch or pain and/or loss of proprioception for most of the body below
the head.
6. Sensation essentially lost below the head.
V. Unknown.
Bowel and Bladder Functions (revised 1982)
0. Normal.
1. Mild urinary hesitancy, urgency, or retention.
2. Moderate hesitancy, urgency, retention of bowel or bladder, or rare urinary
incontinence.
3. Frequent urinary incontinence.
4. In need of almost constant catheterization.
5. Loss of bladder function.
6. Loss of bowel and bladder function.
V. Unknown.
Visual (or Optic) Functions
0. Normal.
1. Scotoma with visual
acuity (corrected) better than 20/30.
2. Worse eye with scotoma with maximal visual acuity (corrected) of 20/30
to 20/59.
3. Worse eye with large scotoma, or moderate decrease in fields, but with
maximal visual acuity (corrected) of 20/60 to 20/99.
4. Worse eye with marked decrease of fields and maximal visual acuity (corrected)
of 20/100 to 20/200; grade 3 plus maximal acuity of better eye of 20/60 or
less.
5. Worse eye with maximal visual acuity (corrected) less than 20/200; grade
4 plus maximal acuity of better eye of 20/60 or less.
6. Grade 5 plus maximal visual acuity of better eye of 20/60 or less.
V. Unknown.
Is added to grades 0 to 6 for presence of temporal pallor.
Cerebral (or Mental) Functions
0. Normal.
1. Mood alteration only (Does not affect DSS score).
2. Mild decrease in mentation.
3. Moderate decrease in mentation.
4. Marked decrease in mentation (chronic brain syndrome-moderate).
5. Dementia or chronic brain syndrome-severe or incompetent.
V. Unknown.
Other Functions.
0. None.
1. Any other neurologic findings attributed to MS (specify).
V. Unknown.
0.0 = Normal neurological exam (all grade 0 in Functional Systems [FS]; Cerebral grade 1 acceptable).
1.0 = No disability, minimal signs in one FS (i.e. grade 1 excluding Cerebral grade 1).
1.5 = No disability minimal signs in more than one FS (more than one grade 1 excluding Cerebral grade 1).
2.0 = Minimal disability in one FS (one FS grade 2, others 0 or 1).
2.5 = Minimal disability in two FS (two FS grade 2, others 0 or 1).
3.0 = Moderate disability in one FS (one FS grade 3, others 0 or 1), or mild disability in three or four FS (three/four FS grade 2, others 0 or 1) though fully ambulatory.
3.5 = Fully ambulatory but with moderate disability in one FS (one grade 3) and one two FS grade 2; or two FS grade 3; or five FS grade 2 (others 0 or 1).
4.0 = Fully ambulatory without aid, self-sufficient, up and about some 12 hours a day despite relatively severe disability consisting of one FS grade 4 (others 0 or 1), or combinations of lesser grades exceeding limits of previous steps. Able to walk without aid or rest some 500 meters.
4.5 = Fully ambulatory without aid, 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; characterised by relatively severe disability, usually consisting of one FS grade 4 (others 0 or 1) or combinations of lesser grades exceeding limits of previous steps. Able to walk without aid or rest for some 300 meters.
5.0 = Ambulatory without aid or rest for about 200 meters; disability severe enough to impair full daily activities (e.g. to work full day without special provisions). (Usual FS equivalents are one grade 5 alone, others 0 or 1; or combinations of lesser grades usually exceeding specifications for step 4.0).
5.5 = Ambulatory without aid or rest for about 100 meters; disability severe enough to preclude full daily activities. (Usual FS equivalents are one grade 5 alone, others 0 or 1; or combinations of lesser grades usually exceeding those for step 4.0).
6.0 = Intermittent or unilateral constant assistance (cane, crutch, or brace) required to walk about 100 meters with or without resting. (Usual FS equivalents are combinations with more than two FS grade 3+).
6.5 = Constant bilateral assistance (canes, crutches, or braces) required to walk about 20 meters without resting. (Usual FS equivalents are combinations with more than two FS grade 3+).
7.0 = Unable to walk beyond about 5 meters even with aid, essentially restricted to wheelchair; wheels self in standard wheelchair and transfers alone; up and about in w/c some 12 hours a day. (Usual FS equivalents are combinations with more than one FS grade 4+; very rarely, pyramidal grade 5 alone).
7.5 = Unable to take more than a few steps; restricted to wheelchair; may need aid in transfer; wheels self but cannot carry on in standard wheelchair a full day; may require motorised wheelchair. (Usual FS equivalents are combinations with more than one FS grade 4+).
8.0 = Essentially restricted to bed or chair or perambulated in wheelchair, but may be out of bed itself much of the day; retains many self-care functions; generally has effective use of arms. (Usual FS equivalents are combinations, generally grade 4+ in several systems).
8.5 = Essentially restricted to bed much of the day; has some effective use of arm(s); retains some self-care functions. (Usual FS equivalents are combinations, generally 4+ in several systems).
9.0 = Helpless bed patient; can communicate and eat. (Usual FS equivalents are combinations, mostly grade 4+).
9.5 = Totally helpless bed patient; unable to communicate effectively or eat/swallow. (Usual FS equivalents are combinations, almost all grade 4+).
10.0 = Death due to MS.
