About EDSS

The Kurtzke Expanded Disability Status Scale (EDSS) is a method of quantifying disability in multiple sclerosis. The scale has been developed by John F. Kurtzke. The EDSS quantifies disability in eight Functional Systems (FS) and allows neurologists to assign a Functional System Score (FSS) in each of these.

1. Visual (optic) functions

Visual acuity


Visual fields

  1. normal
  2. signs only: deficits present only on formal (confrontational) testing
  3. moderate: patient aware of deficit, but incomplete hemianopsia on examination
  4. marked: complete homonymous hemianopsia or equivalent

Scotoma

  1. none
  2. small: detectable only on formal (confrontational) testing
  3. large: spontaneously reported by patient

* Disc pallor

  1. not present
  2. present
  • * optional part of the examination

Note


Functional system score

  1. normal
  2. disc pallor and / or small scotoma and / or visual acuity (corrected) of worse eye less than 20 / 20 (1.0) but better than 20 / 30 (0.67)
  3. worse eye with maximal visual acuity (corrected) of 20 / 30 to 20 / 59 (0.67 – 0.34)
  4. worse eye with large scotoma and/or moderate decrease in fields and/or maximal visual acuity (corrected) of 20 / 60 to 20 / 99 (0.33 – 0.21)
  5. worse eye with marked decrease of fields and/or maximal visual acuity (corrected) of 20 / 100 to 20 / 200 (0.2 – 0.1); grade 3 plus maximal acuity of better eye of 20 / 60 (0.33) or less
  6. worse eye with maximal visual acuity (corrected) less than 20 / 200 (0.1); grade 4 plus maximal acuity of better eye of 20 / 60 (0.33) or less
  7. grade 5 plus maximal visual acuity of better eye of 20 / 60 (0.33) or less
2. Brainstem functions

Extraocular movements (eom) impairment

  1. none
  2. signs only: subtle and barely clinically detectable EOM weakness, patient does not complain of blurry vision, diplopia or discomfort
  3. mild: subtle and barely clinically detectable EOM weakness of which patient is aware; or obvious incomplete paralysis of any eye movement of which patient is not aware
  4. moderate: obvious incomplete paralysis of any eye movement of which patient is aware; or complete loss of movement in one direction of gaze in either eye
  5. marked: complete loss of movement in more than one direction of gaze in either eye

Nystagmus

  1. none
  2. signs only or mild: gaze evoked nystagmus below the limits of “moderate” (equivalent to a Brainstem FS score of 1)
  3. moderate: sustained nystagmus on horizontal or vertical gaze at 30 degrees, but not in primary position, patient may or may not be aware of the disturbance
  4. severe: sustained nystagmus in primary position or coarse persistent nystagmus in any direction that interferes with visual acuity; complete internuclear ophthalmoplegia with sustained nystagmus of the abducting eye; oscillopsia

Trigeminal damage

  1. none
  2. signs only
  3. mild: clinically detectable numbness of which patient is aware
  4. moderate: impaired discrimination of sharp / dull in one, two or three trigeminal branches; trigeminal neuralgia (at least one attack in the last 24 hours)
  5. marked: unable to discriminate between sharp / dull or complete loss of sensation in entire distribution of one or both trigeminal nerves

Facial weakness

  1. none
  2. signs only
  3. mild: clinically detectable facial weakness of which patient is aware
  4. moderate: incomplete facial palsy, such as weakness of eye closure that requires patching overnight or weakness of mouth closure that results in drooling
  5. marked: complete unilateral or bilateral facial palsy with lagophthalmus or difficulty with liquids

Hearing loss

  1. none
  2. signs only: hears finger rub less in one or both sides and has lateralized Weber test but does not complain of any hearing problem
  3. mild: as in 1 but is aware of hearing problem
  4. moderate: does not hear finger rub on one or both sides, misses several whispered numbers
  5. marked: misses all or nearly all whispered numbers

Dysarthria

  1. none
  2. signs only
  3. mild: clinically detectable dysarthria of which patient is aware
  4. moderate: obv. dysarthria during ordinary conversation that impairs comprehensibility
  5. marked: incomprehensible speech
  6. inability to speak

Dysphagia

  1. none
  2. signs only
  3. mild: difficulty with thin liquids
  4. moderate: difficulty with liquids and solid food
  5. marked: sustained difficulty with swallowing; requires a pureed diet
  6. inability to swallow

Other cranial nerve functions

  1. normal
  2. signs only
  3. mild disability: clinically detectable deficit of which patient is usually aware
  4. moderate disability
  5. marked disability

Functional system score

  1. normal
  2. signs only
  3. moderate nystagmus and / or moderate EOM impairment and / or other mild disability
  4. severe nystagmus and / or marked EOM impairment and / or moderate disability of other cranial nerves
  5. marked dysarthria and / or other marked disability
  6. inability to swallow or speak
3. Pyramidal functions

Reflexes (proprioceptive)

  1. absent
  2. diminished
  3. normal
  4. exaggerated
  5. nonsustained clonus (a few beats of clonus)
  6. sustained clonus

Cutaneous Reflexes

  1. normal
  2. weak
  3. absent

* Palmomental Reflex

  1. absent
  2. present

Plantar Response

  1. flexor
  2. neutral or equivocal
  3. extensor

Limb strength

BMRC rating scale

  1. no muscle contraction detected
  2. visible contraction without visible joint movement
  3. visible movement only on the plane of gravity
  4. active movement against gravity, but not against resistance
  5. active movement against resistance, but not full strength
  6. normal strength

Functional tests

* Pronator Drift (upper extremities) Pronation and downward drift:

  1. none
  2. mild
  3. evident

* Position Test (lower extremities – ask patient to lift both legs together, with legs fully extended at the knee) Sinking:

  1. none
  2. mild
  3. evident
  4. able to lift only one leg at a time (grade from the horizontal pos. at the hip joints…°)
  5. unable to lift one leg at a time

* Walking on heels / toes

  1. normal
  2. impaired
  3. not possible

* Hopping on one foot

  1. normal
  2. 6–10 times
  3. 1–5 times
  4. not possible

Limb spasticity (after rapid flexion of the extremity)

  1. none
  2. mild: barely increased muscle tone
  3. moderate: moderately increased muscle tone that can be overcome and full range of motion is possible
  4. severe: severely increased muscle tone that is extremely difficult to overcome and full range of motion is not possible
  5. contracted

Gait spasticity

  1. none
  2. barely perceptible
  3. evident: minor interference with function
  4. permanent shuffling: major interference with function

Overall motor performance

  1. normal
  2. abnormal weakness: (as compared to peers) in performing more demanding tasks, e.g. when walking longer distances, but no reduction in limb strength on formal (confrontational) testing
  3. Reduction in strength: of individual muscle groups at confrontational testing

Functional system score

  1. normal
  2. abnormal signs without disability
  3. minimal disability: patient complains of motor-fatigability or reduced performance in strenuous motor tasks (motor performance grade 1) and/or BMRC grade 4 in one or two muscle groups
  4. mild to moderate paraparesis or hemiparesis: usually BMRC grade 4 in more than two muscle groups;
    and/or BMRC grade 3 in one or two muscle groups (movements against gravity are possible);
    and/or severe monoparesis: BMRC grade 2 or less in one muscle group
  5. marked paraparesis or hemiparesis: usually BMRC grade 2 in two limbs or monoplegia with BMRC grade 0 or 1 in one limb;
    and/or moderate tetraparesis: BMRC grade 3 in three or more limbs
  6. paraplegia: BMRC grade 0 or 1 in all muscle groups of the lower limbs;
    and/or marked tetraparesis: BMRC grade 2 or less in three or more limbs;
    and/or hemiplegia;
  7. tetraplegia: BMRC grade 0 or 1 in all muscle groups of the upper and lower limbss
4. Cerebellar functions

Head tremor

  1. none
  2. mild
  3. moderate
  4. severe

Truncal ataxia

  1. none
  2. signs only
  3. mild: swaying with eyes closed
  4. moderate: swaying with eyes open
  5. severe: unable to sit without assistance

Limb ataxia (tremor/dysmetria and rapid alternating movements)

  1. none
  2. signs only
  3. mild: tremor or clumsy movements easily seen, minor interference with function
  4. moderate: tremor or clumsy movements interfere with function in all spheres
  5. severe: most functions are very difficult

Tandem (straight line) walking

  1. normal
  2. impaired
  3. not possible

Gait ataxia

  1. none
  2. signs only
  3. mild: problems with balance realized by patient and/or significant other
  4. moderate: abnormal balance with ordinary walking
  5. severe: unable to walk more than a few steps unassisted or requires a walking aid or assistance by another person because of ataxia

Romberg test

  1. normal
  2. mild: mild instability with eyes closed
  3. moderate: not stable with eyes closed
  4. severe: not stable with eyes open

Other cerebellar tests

  1. normal
  2. mild abnormality
  3. moderate abnormality
  4. severe abnormality

Note


Functional system score

  1. normal
  2. abnormal signs without disability
  3. mild ataxia and/or moderate station ataxia (Romberg) and / or tandem walking not possible
  4. moderate limb ataxia and / or moderate or severe gait/truncal ataxia
  5. severe gait/truncal ataxia and severe ataxia in three or four limbs
  6. unable to perform coordinated movements due to ataxia
  • X - pyramidal weakness (BMRC grade 3 or worse in limb strength) or sensory deficits interfere with cerebellar testing
5. Sensory functions

Superficial sensation (light touch and pain)

  1. normal
  2. signs only: slightly diminished sensation (temperature, figure-writing) on formal testing of which patient is not aware
  3. mild: patient is aware of impaired light touch or pain, but is able to discriminate sharp/dull
  4. moderate: impaired discrimination of sharp/dull
  5. marked: unable to discriminate between sharp/dull and/or unable to feel light touch
  6. complete loss: anaesthesia

Vibration sense (at the most distal joint)

  1. normal
  2. mild: graded tuning fork 5-7 of 8; alternatively, detects more than 10 seconds but less than the examiner
  3. moderate: graded tuning fork 1-4 of 8; alternatively, detects between 2 and 10 sec
  4. marked: complete loss of vibration sense

Position sense

  1. normal
  2. mild: 1-2 incorrect responses, only distal joints affected
  3. moderate: misses many movements of fingers or toes; proximal joints affected
  4. marked: no perception of movement, astasia

*Lhermitte’s sign

Does not contribute to the Sensory FS score

  1. negative
  2. positive

*Paraesthesiae (tingling)

Does not contribute to the Sensory FS score

  1. none
  2. present

  3. Functional system score

    1. normal
    2. mild vibration or figure-writing or temperature decrease only in one or two limbs
    3. mild decrease in touch or pain or position sense or moderate decrease in vibration in one or two limbs;and/or mild vibration or figure-writing or temperature decrease alone in more than two limbs
    4. moderate decrease in touch or pain or position sense or marked reduction of vibration in one or two limbs;and/or mild decrease in touch or pain or moderate decrease in all proprioceptive tests in more than two limbs
    5. marked decrease in touch or pain in one or two limbs;and/or moderate decrease in touch or pain and/or marked reduction of proprioception in more than two limbs
    6. loss (essentially) of sensation in one or two limbs;and/or moderate decrease in touch or pain and / or marked reduction of proprioception for most of the body below the head
    7. sensation essentially lost below the head
    • * - Does not contribute to the Sensory FS score
6. Bowel and bladder functions

Urinary hesitancy and retention

  1. none
  2. mild: no major impact on lifestyle
  3. moderate: urinary retention; frequent urinary tract infections
  4. severe: requires catheterisation
  5. loss of function: overflow incontinence

Urinary urgency and incontinence

  1. none
  2. mild: no major impact on lifestyle
  3. moderate: rare incontinence occurring no more than once a week; must wear pads
  4. severe: frequent incontinence occurring from several times a week to more than once a day; must wear urinal or pads
  5. loss of function: loss of bladder control

Bladder catheterisation

  1. none
  2. intermittent self-catheterisation
  3. constant catheterisation

Bowel dysfunction

  1. none
  2. mild: no incontinence, no major impact on lifestyle, mild constipation
  3. moderate: must wear pads or alter lifestyle to be near lavatory
  4. severe: in need of enemata or manual measures to evacuate bowels
  5. complete loss of function

* Sexual dysfunction

Male

  1. none
  2. mild: difficulty to maintain erection during intercourse, but achieves erection and still has intercourse
  3. moderate: difficulty to achieve erection, decrease in libido, still has intercourse and reaches orgasm
  4. severe: marked decrease in libido, inability to achieve full erection, intercourse with difficulty and hypoorgasmia
  5. loss of function
  6. Female

    1. none
    2. mild: mild lack of lubrication, still sexually active and reaches orgasm
    3. moderate: dysparunia, hypoorgasmia, decrease in sexual activity
    4. severe: marked decrease in sexual activity, anorgasmia
    5. loss of function
    6. Note


      Functional system score

      1. normal
      2. mild urinary hesitancy, urgency and / or constipation
      3. moderate urinary hesitancy/retention and / or moderate urinary urgency/incontinence and /or moderate bowel disfunction
      4. frequent urinary incontinence or intermittent self-catheterisation; needs enemata or manual measures to evacuate bowels
      5. in need of almost constant catheterisation
      6. loss of bladder or bowel function; external or indwelling catheter
      7. loss of bowel and bladder function
7. Cerebral functions

Depression and euphoria

  1. none
  2. present: Patient complains of depression or is considered depressed or euphoric by the investigator or significant other

Decrease in mentation

  1. none
  2. signs only: not apparent to patient and / or significant other
  3. mild: Patient and / or significant other report mild changes in mentation. Examples include: impaired ability to follow a rapid course of association and in surveying com- plex matters; impaired judgement in certain demanding situations; capable of hand- ling routine daily activities, but unable to tolerate additional stressors; intermittently symptomatic even to normal levels of stress; reduced performance; tendency toward negligence due to obliviousness or fatigue
  4. moderate: definite abnormalities on brief mental status testing, but still oriented to person, place and time
  5. marked: not oriented in one or two spheres (person, place or time), marked effect on lifestyle
  6. dementia, confusion and/or complete disorientation

+Fatigue

  1. none
  2. mild: does not usually interfere with daily activities
  3. moderate: interferes, but does not limit daily activities for more than 50 %
  4. severe: significant limitation in daily activities (> 50 % reduction)

Functional system score

  1. normal
  2. signs only in decrease in mentation; mild fatigue
  3. mild decrease in mentation; moderate or severe fatigue
  4. moderate decrease in mentation
  5. marked decrease in mentation
  6. dementia
8. Ambulation

Unrestricted ambulation


Fully ambulatory

If ambulation is < 500 meters

If assistance is needed

  • If assistance is needed,the definitions of EDSS steps 6.0 or 6.5 include both a de- scription of the type of assistance required when walking and the walking range. Assi- stance by another person is equivalent to bilateral assistance.
  • The ambulation score

  • The ambulation scorerepresents both a description of walking range and the type of assistance required for ambulation. The score replaces the former use of several checkboxes (paragraph 8 ambulation on the scoring sheet) but does NOT introduce new definitions. The use of wheelchair can now be scored on the scoring sheet.Please indicate the reported distance and time for the patient in the appropriate field on the scoring sheet, followed by the type of assistance and the walking distance measured during the assessment.
  • Distance and time reported by patient

  • Maximal unassisted walking distance reported by patient (in meters) without rest or assistance and time required to walk max. distance according to patient (in minutes)
  • Assistance

    1. Without help or assistance (allowing the use of an ankle foot orthotic device, without any other type of assistive device)
    2. Unilateral assistance: one stick/crutch/brace
    3. Bilateral assistance: two sticks/crutches/braces or assistance by another person
    4. Wheelchair
    5. Distance

    6. Measure the distance the patient is able to walk im meters.
    7. Unassisted: observe the patient walking unassisted for a minimum distance of 500 meters and measure the time needed, if possible.
    8. Assisted: observe the patient walking with the assistive device or help by another person for a minimum distance of 130 meters, if possible.
    9. Ambulation score

      1. Unrestricted
      2. Fully ambulatory
      3. ≥ 300 meters, but < 500 meters, without help or assistance (EDSS 4.5 or 5.0)
      4. ≥ 200 meters, but < 300 meters, without help or assistance (EDSS 5.0)
      5. ≥ 100 meters, but < 200 meters, without help or assistance (EDSS 5.5)
      6. Walking range < 100 meters without assistance (EDSS 6.0)
      7. unilateral assistance, ≥ 50 meters (EDSS 6.0)
      8. bilateral assistance, ≥ 120 meters (EDSS 6.0)
      9. unilateral assistance, < 50 meters (EDSS 6.5)
      10. bilateral assistance, ≥ 5 meters, but < 120 meters (EDSS 6.5)
      11. Uses wheelchair without help; unable to walk 5 meters even with aid, essenti- ally restricted to wheelchair; wheels self and transfers alone; up and about in wheelchair some 12 hours a day (EDSS 7.0)
      12. Uses wheelchair with help; unable to take more than a few steps; restricted to wheelchair; may need some help in transferring and in wheeling self (EDSS 7.5)
      13. essentially restricted to bed or chair or perambulated in wheelchair, but out of bed most of day; retains many self-care functions; generally has effective use of arms (EDSS 8.0)
    9. Expanded disability status scale

    0 - normal neurological exam (all FS grade 0)

    1,0 - no disability, minimal signs in one FS (one FS grade 1)

    1,5 - no disability, minimal signs in more than one FS (more than one FS 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) though fully ambu- latory; 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 FS grade 3) and mild disability in one or two FS (one / two FS grade 2) and others 0 or 1; or fully ambu- latory with two FS grade 3 (others 0 or 1);or fully ambulatory with five FS grade 2 (others 0 or 1)

    4,0 - ambulatory without aid or rest for $500 meters; 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

    4,5 - ambulatory without aid or rest for $300 meters; up and about much of the day, a characterised by relatively severe disability usually consisting of one FS grade 4 and combination of lesser grades exceeding limits of previous steps

    5,0 - ambulatory without aid or rest for $200 meters (usual FS equivalents include at a least one FS grade 5, or combinations of lesser grades usually exceeding specifi- cations for step 4.5)

    5,5 - ambulatory without aid or rest for $100 meters

    6,0 - unilateral assistance (cane or crutch) required to walk at least 100 meters with u or without resting (see chapter 8, Ambulation)

    6,5 - constant bilateral assistance (canes or crutches) required to walk at least 20 me- cters without resting (see chapter 8, Ambulation)

    7,0 - unable to walk 5 meters even with aid, essentially restricted to wheelchair; wheels self 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; may need some help in transferring and in wheeling self

    8,0 - essentially restricted to bed or chair or perambulated in wheelchair, but out of bed most of day; retains many self-care functions; generally has effective use of arms

    8,5 - essentially restricted to bed much of the day; has some effective use of arm(s); retains some self-care functions

    9,0 - helpless bed patient; can communicate and eat

    9,5 - totally helpless bed patient; unable to communicate effectively or eat/swallow)

    10 - death due to MS

    Algoritm of EDSS Calculator
    EDSS step   FS 0 FS 1 FS 2 FS 3 FS 4 FS 5/6   Ambulation
    0 7 ×          

    0

    unrestricted

    1,0   1 ×        
    1,5   2−7 ×        
    2,0     1 ×      

    0 − 1

    fully ambulatory (means at least 500 m of ambulation without assistance, but not unrestricted)

    2,5     2 ×      
    3,0     3−4 ×      
        0 × 1 ×    
    3,5     5 ×      
        1−2 × 1 ×    
        0 × 2 ×    
    4,0     6−7 ×      
          2−4 ×    
        0 × 0 × 1 ×  
     
    4,5         5 ×       2

    300–499 m

          1−2 × 1 ×  
    5,0       6−7 ×     3

    200–299 m

            2−7 ×  
              1−7 ×
     
    5,5   4 100 meters, but < 200 meters, without help or assistance
    6,0 5 Walking range < 100 meters without assistance
    6 Unilateral assistance, 50 meters
    7 Bilateral assistance, 120 meters
    6,5 8 Unilateral assistance, 50 meters
    9 Bilateral assistance, 5 meters, but < 120 meters
    7,0 10 Uses wheelchair without help; unable to walk 5 meters even with aid, essentially restricted to wheelchair; wheels self and transfers alone; up and about in wheelchair some 12 hours a day
    7,5 11 Uses wheelchair with help; unable to take more than a few steps; restricted to wheelchair; may need some help in transferring and in wheeling self
    8,0 12 Essentially restricted to bed or chair or perambulated in wheelchair, but out of bed most of day, retains many self-care functions; generally has effective use of arms
    

    Authors of online EDSS calculator: Farit Khabirov, Timur Khaibullin, Evgenii Granatov, Guzel Akhmedova.