Article abstract—One method of evaluating the degree of neurologic impairment in MS has been the combination of
`grades (0 = normal to 5 or 6 = maximal impairment) within 8 Functional Systems (FS) and an overall Disability Status
`Scale (DSS) that had steps from 0 (normal) to 10 (death due to MS). A new Expanded Disability Status Scale (EDSS) is
`presented, with each of the former steps (1,2,3 ... 9) now divided into two (1.0, 1.5, 2.0 ... 9.5). The lower portion is
`obligatorily defined by Functional System grades. The FS are Pyramidal, Cerebellar, Brain Stem, Sensory, Bowel &
`Bladder, Visual, Cerebral, and Other; the Sensory and Bowel & Bladder Systems have been revised. Patterns of FS and
`relations of FS by type and grade to the DSS are demonstrated.
`NEUROLOGY(Cleveland) 1983;33:1444-52
`
`Rating neurologic impairment
`in multiple sclerosis:
`An expanded
`disability status scale (EDSS)
`
`John F. Kurtzke, MD
`
`In 1955 I described “a new scale for evaluating dis-
`ability in multiple sclerosis,’ later known as the
`Disability Status Scale (DSS), devised to evaluate
`isoniazid as a possible treatment.2 This scale wasalso
`usedin the first multicentered, randomized,placebo-
`controlled, double-blind trial of MS therapy,? which
`refuted ouroriginal claim, a decision with which we
`had to concur from ourlater experience.* The DSS
`had 10 grades or steps beyond 0 (normal), extending
`to status 10 (death due to MS). The scale was
`“Intended to measure the maximal function of each
`patient as limited by .
`.
`. neurologic deficits,” and it
`was based on neurologic examination.
`The DSS was later made half of a bifid rating
`system, the other part “being a series of grades in
`each of eight functional groupings. ... In each por-
`tion, there is a numerical rating which is mutually
`exclusive in its category, and the higher the number,
`the greater is the dysfunction. Only objectively ver-
`ifiable defects due to multiple sclerosis as elicited
`upon neurologic examination are included. Symp-
`toms are discarded.”®
`The functional groups, later called Functional
`Systems (FS), were Pyramidal (P), Cerebellar (Cll),
`Brain Stem (BS), Sensory (S), Bowel & Bladder
`(BB), Visual (V), Cerebral or Mental (Cb), and Other
`or Miscellaneous (O) Functions. All save the last
`
`were graded from 0 (normal) to maximal impairment
`(grade 5 or 6); the “Other” FS was dichotomous, with
`0 as none and 1 as any present. Approximate equiv-
`alents for the DSS steps were also provided. The
`Functional Systems were mutually exclusive in
`terms of neuroanatomy, but together comprisedall
`neurologic abnormalities on examination that can be
`attributed to MSlesions. The FS were not additive;
`each FS could be compared overtimeonly withitself,
`and for this reason it was necessary to retain the DSS
`for overall comparisons of the same patient at dif-
`ferent examinations.
`The FS were modified in 1965 by changing the
`Sensory scale from 0-5 to 0-6 and redefining the
`upper grades for Bowel & Bladder.® As will be seen
`below, the Sensory System is again being revised,
`and Bowel & Bladder has a newstep.
`This two-part system of assessing neurologic
`impairment in MShas been used in several studies,
`and it has been proposed for adoption as one part ofa
`tridimensional schemefor a “minimal data set” in
`MS, which will be discussed below. However, some
`investigators believe the DSSis too insensitive to
`changein the middle ranges, and have urged division
`of step 7 into two parts. Further, while the DSS was
`consideredsatisfactory in several treatmenttrials in
`acute bouts,it was thought that there should be more
`
`
`
`From the Neurology Service, Veterans Administration Medical Center and Departments of Neurology and of Community Medicine, Georgetown University
`School of Medicine, Washington, DC.
`Accepted for publication February 9, 1983.
`Address correspondence and reprint requests to Dr. Kurtzke, Chief, Neurology Service (127), Veterans Administration Medical Center, 50 Irving Street, NW,
`Washington, DC 20422.
`
`1444 NEUROLOGY33 November 1983
`
`Hopewell EX1010
`
`Hopewell EX1010
`
`1
`
`

`

`room for changein studies of chronic MS.
`For these reasons, an Expanded DSS (EDSS)is
`now presented. It provides, for each step from 1
`through 9, two steps that together add up to the same
`step of the original DSS. This division relies even
`more heavily on the standard neurologic examina-
`tion as encoded in the Functional Systems.In fact,it
`is fully defined in the lower ranges by the FS grades.
`For this reason, before presenting the Expanded
`DSS,we need to consider the Functional Systems.
`
`Functional Systems. The grades for each of the
`Functional Systemsare defined in appendix A. They
`are identical with those provided in 1965° except for
`the new Sensory and Bowel & Bladder Systems. The
`frequency of involvement in each system at admis-
`sion to the hospital for an early bout of MS in one
`series is described in table 1.”
`Recall that each FS is independentof the others,
`yet togethertheyreflect all neurologic impairment in
`MS. There are over 1.3 million possible patterns of
`involvement by FS type and grade. However, if we
`consider each System as just involved (1) or not
`involved (0), then neurologic impairment can be
`defined by an eight-digit binary number. For exam-
`ple, a patient with Pyramidal, Cerebellar, and Sen-
`sory signs, the other Systems normal, would be
`described as 1101 0000. There are then only 256 possi-
`ble patterns (2°) into which a patient can fall. From
`the sameseries as in table 1, there are described the
`most common patterns to be expected if lesions in
`one system were independentoflesionsin the others
`(table 2). These expected frequencies compare well
`with those actually observed for the samespecific
`patterns.’ One-half of the patients fell into one of
`only 14 patterns, and 1/4 into one of only 4 patterns.
`Several points ofclarification may be in order for
`the Functional Systems. Pyramidal, Cerebellar, Sen-
`sory, and Bowel & Bladder functions all refer to
`impairment of body parts below the head only
`(regardless of the site of the lesions), and Brain Stem
`functions have always referred to impairment
`“attributable to lesions of supra- and intersegmental
`tracts subservingcranial nerves 3 through 12, together
`with involvementof these nuclei or their intramedul-
`lary fibers. These, therefore ... encompass
`pseudobulbarpalsies and scanning speech. . . in addi-
`tion to the so-called cranial nerve functions.”*
`For each FS and the DSS, the rule remains:
`“Wherecriteria for the precise grade are not met, the
`nearest appropriate category is utilized.”> Thus
`Pyramidal grade 5 would be used rather than 4 for
`one whois almost paraplegic. Whatever the specific
`grade definition, then,“almost”or “practically” can
`be prefixed. One methodfordifficult decisionsis to
`“bracket”the likely grade and then cone downon the
`most applicable.
`
`The Expanded Disability Status Scale. The
`EDSS (appendix B) will be discussed under con-
`
`Table 1. Percentage frequency of involvement
`according to Functional Systems
`(FS)
`from
`neurologic examinations at admission to hospital
`for an early bout of MS; Army WW II series*
`
`Functional
`Systems (FS)
`
`Pyramidal (P)
`Cerebellar (Cll)
`Brain Stem (BS)
`Sensory (S)
`Bowel & Bladder (BB)
`Visual’ (V)
`Cerebral-totalt (Cb)
`Cerebral-mentation$
`Other (O)
`
`% involved
`
`84.9
`76.9
`13.0
`55.2
`22.6
`33.9
`20.7
`2.9
`14.9
`
`*From Kurtzke etal, Acta Neurol Scand 1972;48:19-46.
`* Neuropathic signs either/both eyes; see *.
`* Includes mood changesonly (step 1).
`§ Steps 2+ on thescale.
`
`
`{E) patterns.
`
`Table 2. Patterns of involvement by Functional
`System (FS) from neurologic examinations at
`admission to hospital for an early bout of MS;
`Army WWII series*
`
`Pattern?
`
`1111 0000
`1110 0000
`1111 0100
`1110 0100
`1101 0000
`1100 0000
`1011 0000
`1010 0000
`1111 0010
`1110 0010
`1111 1000
`1110 1000
`0111 0000
`0110 0000
`all other
`
`SwanrRWN
`
`15-256
`
`256
`
`Total
`
`No. of cases
`oO
`E
`
`Cumulative p*
`Oo
`E
`
`31
`29
`12
`16
`14
`8
`6
`7
`15
`8
`11
`4
`1
`9
`164
`
`335
`
`0.093
`0.179
`0.215
`0.263
`0.304
`0.328
`0.346
`0.367
`0.412
`0.436
`0.469
`0.481
`0.484
`0.510
`1.000
`
`0.086
`0.172
`0.218
`0.263
`0.291
`0.319
`0.345
`0.371
`0.395
`0.418
`0.439
`0.460
`0.478
`0.497
`1.000
`
`1.000
`
`1.000
`
`* Adapted from Kurtzke, Acta Neurol Scand 1970;46:493-512.
`* Rank order of expected frequency of specific pattern, based upon
`product of individual observed frequencies with hypothesis of
`independencefor all patterns where E = 5.0; O = observed and
`E = expected frequency. x’,, = 20.58, p > 0.10 for O versus E.
`* Involved (1) or not involved (0) for P, Cll, BS, S, BB, V, Cb, O in
`cited order; cases with complete information onall 8 FS.
`§ Cumulative proportion (p) of total, observed (QO), and expected
`
`November 1983 NEUROLOGY33 1445
`
`2
`
`

`

`Table 3. Percentage frequency distribution of Functional System (FS) grades according to DSSsteps.
`I: DSS 1-2*
`
`2
`
`FS grades
`3
`(percentages)
`
`4
`
`6
`
`
`
`86.6
`
`13.4
`
`Data from some 2,000 exams in 20 years among 527 males, Army WWIIseries.
`Excludes those with Pyramidal grade 3+.
`1961 scales.
`* VA Hospital series (N = 392).
`No cases.
`Not applicable; step(s) not in scale.
`
`secutive groupings of the original DSS. For this
`expansion, we have had to make more finite and
`arbitrary distinctions than in the originalscale.
`DSS Step 0. As before, this defines the normal
`neurologic examination—regardless of symptoms.
`Therefore, all FS are grade 0, except for Cerebral
`System grade 1. Cerebral “grade 1 refers to mood
`aberrations such as euphoria or depression, which
`may not be a primary effect of the disease process,
`but this is hoped to represent that stage of brain
`damage whenalterations of personality or emotional
`control are the sole features.”® For DSS step 0 and
`step i, Cerebral grade 1 is treated as a 0.
`DSS Steps 1-2. These steps refer to minimal
`objective abnormality, with step 1 as signs without
`impaired function. Table 3 shows the distribution of
`FS grades for DSS 1-2 from an overview of some 20
`years’ follow-up examinations in 527 men with MS,
`our Army WW II series.® The ratio of step 2 to 1 was
`about 2:1. The DSS scores in this series were not
`strictly delimited by the FS equivalents described
`here. Nevertheless, the low frequency of involvement
`is evident; this was essentially limited to FS grades 1
`and 2 except for the 7% in Brain Stem grade 3. The
`FSscales used here and below are the 1961 variants
`for Sensory and Bowel & Bladder.
`EDSSStep 1.0 is limited to one FS grade1, exclud-
`ing Cerebral grade 1, with all others grade 0.
`EDSSStep 1.5 is defined as two or more FS grade
`1, again excluding Cerebral grade 1, but no grade
`above 1 in any FS.
`EDSSStep 2.0 is limited to one FS grade 2, others
`grade 0 or 1.
`EDSSStep 2.5 is limited to two FS grade 2, others
`grade 0 or 1.
`Note thatit is irrelevant which FSare involved, and
`from table 3, it is likely to be any of them except
`Bowel & Bladder or Cerebral.
`DSS Steps 3-4. These steps still refer to mild
`disorder, not sufficient to impede normalactivities of
`
`1446 NEUROLOGY33 November 1983
`
`daily living or work in most situations. However, a
`concert pianist, a pilot, or a steeplejack would doubt-
`less not be able to function as usual andstill be
`ascribable to these steps. Full ambulation—meaning
`ability to be up and aboutall day and to walk usual
`distances without resting—characterize these steps.
`Impaired ambulation of any degree should not occur
`with FS grades defining DSSstep 3. There is some
`overlap of FS in steps 4 and 5. Table 4 delineates the
`distribution of FS grades for DSS 3-4. The ratio of
`step 3 to 4 was about unity. Only rarely was grade 4
`attained. Webegin to see the predominance of Pyra-
`midal involvement, closely followed by Cerebellar
`and Brain Stem.
`EDSS Step 3.0 is limited to one FS grade 3, or
`three or four FS 2, others being 0 or 1.
`EDSSStep 3.5 is limited to one FS grade 3 plus
`one or two grade 2, or two FS grade 3,or five FS grade
`2, others being grade 0 or 1.
`EDSS Step 4.0 consists of combinations just
`exceeding two grade 3, or one grade 3 plus two grade
`2, or five grade 2; or one FS grade 4 alone,all others
`being grade 0 or 1. At this point, the ambulation/
`work/daily activity abilities start to take precedence
`over the precise FS grades. With FS that exceed the
`criteria for EDSSstep 3.5, there mustbe,for step 4.0,
`full ambulation (includingability to walk withoutaid
`or rest for some 500 meters), and ability to carry out
`full daily activities to include work of average physi-
`cal difficulty.
`EDSS Step 4.5 has the same minimal FS grade
`requirementsas step 4.0. The patient must be able to
`walk withoutaid or rest for some 300 meters and to
`worka full day in a position of average difficulty. The
`patient is up and about most of the day, but some
`limitation of full activity separates this from step 4.0.
`DSS Steps 5-6. The patient is not ordinarily
`houseboundandcan walk. Seldom is a full work day
`possible without special provisions. The original
`DSS 5 was defined as “maximal motor function
`
`3
`
`

`

`Table 4. Percentage frequency distribution of Functional System (FS) grades according to DSS steps.
`II: DSS 3-4*
`
`1
`
`19.9
`11.6
`27.1
`6.5
`TA
`2.8
`16.8
`15.2
`
`18.5
`26.5
`29.8
`49.4
`TTA
`60.6
`80.3
`84.8
`
`2
`
`‘
`.
`:
`.
`i
`.
`
`FS grades
`3
`(percentages)
`
`4
`
`5
`
`6
`
`35.1
`16.9
`19.0
`12.2
`3.7
`9.2
`
`NA
`
`Data from some 2,000 exams in 20 years among 527 MS males, Army WWIIseries.
`Excludes those with Pyramidalgrade 3+.
`1961 scales.
`* VA Hospital series (N = 392),
`Nocases.
`
`Not applicable; step(s) not on the scale.
`Notapplicable; step(s) not in scale.
`
`Table 5. Percentage frequency distribution of Functional System (FS) grades according to DSSsteps.
`TI: DSS 5-6*
`
`1
`
`6.6
`2.5
`23.1
`1.2
`10.5
`6.4
`20.7
`27.9
`
`2
`
`.
`‘
`:
`‘i
`;
`:
`
`t
`
`2.1
`5.6
`19.2
`29.8
`59.3
`60.8
`72.6
`W2A
`
`FS grades
`3
`(percentages)
`
`4
`
`5
`
`6
`
`49.5
`56.7
`26.0
`22.4
`10.1
`11.2
`
`NA
`
`Data from some 2,000 examsin 20 years among 527 MS males, Army WWIIseries.
`Excludes those with Pyramidal grade 3+.
`1961 scales.
`8S VA Hospitalseries.
`Nocases.
`
`walking unaided upto several blocks,” and for 6 it
`was “assistance required for walking.”! There is
`generally some impairmentin usual daily activities.
`Table 5 indicates for these steps the increasing fre-
`quency and severity of FS involvement, particularly
`Pyramidal and Cerebellar systems, with Brain Stem
`and Sensory not far behind. Theratio of step 5 to 6
`wasabout1.7:1. The principal discrimination among
`these four new EDSSsteps rests with walking; the
`patient’s statements about walking are ordinarily
`acceptable, but direct observation—and on more
`than one occasion—may be required. We are after
`“usual best function” here, and neither supramaxi-
`malnorinsufficient efforts at performance. The FS
`equivalents are advisory and not prescriptive for
`these and highersteps.
`EDSSStep 5.0 requires ambulation for about 200
`
`meters without aid or rest. Disability is severe
`enoughto impairfull daily activities, eg, to work a full
`day withoutspecial provisions. Usual FS equivalents
`are one grade 5 alone, others 0 or 1, or combinations
`of lesser grades that will usually exceed those spec-
`ified for EDSSstep 4.0.
`EDSSStep 5.5 requires ambulation for some 100
`meters without aid or rest. Other criteria are
`inability to work part-time (about }2 day) without
`special provisions. Usual FS equivalents are as in
`step 5.0. Note the arbitrary distances for walking
`ability.
`EDSSStep 6.0 requires assistance to walk about
`100 meters. This may mean resting, the use of uni-
`lateral aids (cane, crutch, or brace) at most times, or
`the intermittent use of bilateral aids. The assistance
`of another person also counts as “with aid.” The
`
`November 1983 NEUROLOGY 33 1447
`
`4
`
`

`

`Table 6. Percentage frequency distribution of Functional System (FS) grades according to DSSsteps.
`IV: DSS 7-9*
`
`2
`
`FS grades
`3
`(percentages)
`
`3.0
`
`4
`
`6
`
`
`
`0.7
`1.0
`17.9
`28.1
`20.3
`54.1
`67.9
`57.9
`
`Data from some 2,000 examsin 20 years among 527 MS males, Army WWIIseries.
`Excludes those with Pyramidal grade 3+.
`1961 scales.
`’ VA Hospital series (N = 392).
`No cases.
`Not applicable; step(s) not on the scale.
`
`primary measurefor this step is the ability to walk
`with help for about 100 meters. Usual FS equiv-
`alents are combinations with more than two FS
`grade 3+.
`EDSSStep 6.5 requires assistance to walk about
`20 meters without resting by means of aids (canes,
`crutches, braces, or people), which are generally
`bilateral and generally constantly necessary. Usual
`FS equivalents are as in 6.0—combinations with
`more than two FS grade 3+. A person who cannot
`walk 20 meters is functionally almost nonambula-
`tory and should be considered close to DSS 7.
`DSS Steps 7-9. These are the severely involved
`patients whoare almost invariably limited to wheel-
`chair or bed. Table 6 demonstrates the marked shift
`to the right for FS grade involvement, particularly
`those functions having to do with ambulation. This
`behavior of groups of MSpatients lendsvalidity to a
`scoring system that stresses ambulation in the higher
`ranges; only in the most severe will the loss of upper
`limb and head functions be added. Theratio of the
`steps here was about1.4:1:1.
`The original definition of DSS step 7 was
`“restricted to wheelchair (able to wheel self and enter
`and leave chair alone).... It does not include the
`patient whois tied in the chair and perambulated.”™
`Conversely, ability to walk short distances is not
`sufficient to qualify for step 6. The arbitrary limit for
`“short distances” is taken here as about 5 meters.
`This provides some leeway between EDSSstep 6.5
`(20 meters) and 7.0 (5 meters). As with the other
`grades, assignmentis to that closest to his perfor-
`mance.
`EDSS Step 7.0 defines essential restriction to
`wheelchair with inability to walk beyond about 5
`meters even with aid. Patients can transfer alone
`(with mechanical aids if needed) and wheel the stan-
`dard wheelchair; are able to be up and about in the
`
`1448 NEUROLOGY33 November 1983
`
`chair some 12 hours a day; with the chair, are not
`housebound and may even be employed. Usual FS
`equivalents are combinations with more than one FS
`grade 4+; rarely, Pyramidal grade 5 alone.
`EDSS Step 7.5 describes inability to take more
`thana few steps and,essentially, restriction to wheel-
`chair. With or without aid, these patients can trans-
`fer. They can wheel themselves, but cannot carry on
`in standard wheelchair a full day. They may require
`motorized wheelchair for ability to be up and about
`in the chair. Usual equivalents are combinations
`with more than one grade 4+.
`EDSSStep 8.0. The original DSS8 definition was
`“restricted to bed but with effective use of the arms
`...} he can usually feed himself and perform part of
`his toilet.’In our setting, it has been standard pro-
`cedure to get bed patients into chairs as much as
`possible, so that the horizontal posture was not a
`requirementfor “bed patient.” This (to me) obvious
`point has led to some confusion as to requirements
`for DSS8.
`EDSSStep8.0 is defined as bed patients who may
`be in chair or (passively) in wheelchair for much of
`the day, and it is so specified in appendix B. Pri-
`marily, though, they retain manyself-care functions
`and generally have effective use ofthe arms. Usual FS
`equivalents are combinations, generally grade 4+ in
`several systems.
`EDSS Step 8.5 are the bed patients who in
`daytime generally cannot tolerate prolonged periods
`in chair and are more often in bed, unlesstied in the
`chair. Primarily, they still have someeffective use of
`one or both arms and can perform someself-care
`functions, but less than for step 8.0. Usual FS equiv-
`alents are as in step 8.0.
`EDSSStep 9.0 are the “helpless bed patients” who,
`however, can communicate and eat. They cannot per-
`form self-care functions (such as feeding), Usual FS
`
`5
`
`

`

`MS: COURSE IN HOSPITAL - TOTAL SERIES
`
`DISCHARGE
`
`ADMISSION DSS
`
`
`
`* Army WWIIseries, overview for some 20 years (data are percentages).
`
`Total
`N
`
`100.1
`(350)
`
`99.9
`(1,665)
`
`* VA Hospital series, admission status (data are percentages).
`
`Table 7. DSS: Percentage frequency distribution
`in two series of MS patients at examination
`
`Series 1*
`
`Series 2+
`
`01 2 34 5 67 8 9 0
`
`1
`
`equivalents are combinations, mostly grade 4+.
`EDSSStep 9.5 defines the totally helpless bed
`patients who cannot communicateeffectively, eat, or
`swallow. Usual FS equivalents are combinations,
`almost all grade 4+.
`EDSSStep 10 is death due to MS. This may be an
`acute death due to “brainstem” involvement or to
`respiratory failure,? or death consequent to the
`chronic bedridden state with terminal pneumonia,
`sepsis, uremia, cardiorespiratory failure. It excludes
`intercurrent causes of death. Antemortem, the
`patient will ordinarily be DSS 9, sometimes8.
`
`Discussion. The expanded DSS should answer the
`needs of those whofelt constrained by too few steps in
`the original scale. The reason each step had to be
`divided, rather than only a few steps, may be seen in
`table 7, which showsthe distribution of DSS scores in
`two series of MSpatients. In our hands,at least, the
`distribution was reasonably Gaussian, and no single
`step stood out as markedly discrepant. With this evi-
`dence, the DSScouldin fact be treated as a true numer-
`ical scale, with means and standard deviations, rather
`than the ordinal (rank) scale thatis its basic structure.
`This would imply that DSS6 is twice as “bad”as DSS3.
`In several studies, a clearly bimodal distribution of
`DSS scores was found. Comparing the individual FS
`scores with DSS in many of these (published and
`unpublished) suggests that the DSS scores below 6 had
`been assigned with little regard to FS grades. This
`should be obviated if the new EDSSis used—oreven if
`the old DSS were retained, but with the FS equivalents
`given here. The sum of the two EDSSstepsof the same
`number,eg, 2.0 + 2.5, would be identical with the old
`DSS number, ie 2. In one unpublished study, one
`DSSstep was dramatically higher than all others. I
`
`Figure. Grid correlate of DSS at admission to and
`discharge from hospital for an early bout of MS; Army
`WWII series.’ Numbers along the main diagonal(0, 0
`... 9, 9) indicate no change in DSS between admission
`and discharge; those above the diagonal improved and
`those below worsened, by the numberof steps off
`diagonalfor each locus.
`
`suspect this was miscodingof contiguoussteps, since
`nowhereelse have I seen this.
`Thethesis that the DSSis a true numerical, equal-
`interval scale, though,is irrelevant to what I believe
`to be the proper handling of the scale as an index of
`neurologic change with time. To me, the Gaussian
`appearanceis important principally in deciding that
`no one step is superfluous, and that no one step is
`really two or more steps on the continuum from
`normal to maximal disease. This appearance of a
`normaldistribution is the basic reason for the EDSS
`as presented, with each prior step divided in half.
`As to mypreferred way of handling DSSscores over
`time, it remains the sameas previously. Improvement
`or worsening for each patient was defined as a gain or
`loss of at least one step on the DSS. This should not
`happen unlessat least one FS changed by an equivalent
`degree in the same direction. The plotting of cases at
`two intervals would then be most easily accomplished
`by a grid correlate of DSSscores at time 1 versus DSS
`scores at time 2. The numbers moving off the major
`diagonal of no change provide the numbers improving
`or worsening by one, two, three or moresteps(figure).
`Thenthe proportions better-same-worse could be com-
`pared between two regimensif this were a therapeutic
`trial.
`With the EDSS,a gain/loss of 0.5 steps will be
`defined as better/worse, but again, greater changes can
`be recorded. I cannot assert that each EDSSgain of 0.5
`
`November 1983 NEUROLOGY33 1449
`
`6
`
`

`

`shouldbe accompanied by a changein FS of at least one
`grade, but I would be suspicious of the DSS changeif
`this were not evident.
`In other words, despite the Gaussian configuration
`of the DSS,I still prefer to treat it as an ordinal scale.
`For the FS, the only proper assessment is to consider
`each System individually, to plot “in” versus “out” asa
`grid correlate as with the DSS, and then to look at
`proportions changing in simile modo. Further, the FS
`scores are not additive, and each system can be com-
`pared only with itself. One obvious reason is that as
`Pyramidal worsens, Cerebellar will “improve,” since
`patients cannotbe ataxic ifthey cannot move. The lack
`of additivity in these systems was the underlying rea-
`son for the DSS.Also,I believe that mean FSscores are
`difficult to defend, even when speaking only to the
`individual systems. The distributions for most of them
`are clearly non-Gaussian (tables 3 through 6), and they
`also have differing configurations one versus another.
`In the introduction, another impetus behind the
`paper was mentioned. TheInternational Federation of
`Multiple Sclerosis Societies (IFMSS) is trying to
`establish a Uniform Minimum Record of Disability,
`which would be internationally acceptable as a way to
`characterize MS patients.!° Three separate scales
`were desired: one rating schemeto record the neu-
`rologic signs, one to record the physical disabilities or
`impairments, and oneto record the societal impact of
`the disease. With differing labels, this follows the
`schema recommended by the World Health Organi-
`zation to classify the consequencesof disease accord-
`ing to “impairments” (neurologic abnormalities),
`“disabilities,” and “handicaps.’”!
`At a meeting in Stockholm”it was thoughtthat,
`for what by WHOwascalled (neurologic) “‘impair-
`ment,” the rating scheme presented here—the DSS
`plus FS—was the most likely to meet with, if not
`universal acceptance, at least minimal opposition
`when compared with other proposals. The wide use
`of this method was documented.'? For the physical
`impairmentsor“disabilities” resulting from the dis-
`ease, an Incapacity Scale was devised—a term
`chosen deliberately because it had not yet been
`appropriated by any other scheme.” The societal
`impact (WHO: “handicaps”) was assayed by what
`was then called a Socio-Economic Scale."4 Both the
`latter scales have been undergoingrevisions, the eco-
`nomic one most drastically. IFMSS is continuing
`these efforts to establish and test. a commontripar-
`tite schemethat would be suitable for all centers.
`
`Appendix A. Functional Systems.
`
`Pyramidal Functions
`0. Normal.
`1. Abnormal signs without disability.
`2. Minimal disability.
`3. Mild or moderate paraparesis or hemiparesis;
`severe monoparesis.
`
`1450 NEUROLOGY 33 November 1983
`
`4, Marked paraparesis or hemiparesis; moderate
`quadriparesis; or monoplegia.
`5. Paraplegia, hemiplegia, or marked quad-
`riparesis.
`6. Quadriplegia.
`V. Unknown.
`
`Cerebellar Functions
`0. Normal.
`1. Abnormalsigns withoutdisability.
`2. Mild ataxia.
`3. Moderate truncalor limb ataxia.
`4. Severe ataxia,al! 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) in-
`ter feres 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.
`
`os
`
`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.
`. Moderate decrease in touchor 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 inall 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
`bowelor bladder, or rare urinary incontinence.
`
`7
`
`

`

`Amonoo
`
`. Frequent urinary incontinence.
`. In need of almost constant catheterization.
`. Loss of bladder function.
`. Loss of bowel and bladder function.
`. Unknown.
`
`2.0 = Minimaldisability 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).
`
`Visual (or Optic) Functions
`0. Normal.
`1. Scotoma with visual acuity (corrected) better
`than 20/30.
`2. Worse eye with scotoma with maximalvisual
`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 offields and
`maximalvisual acuity (corrected) of 20/100 to
`20/200; grade 3 plus maximal acuity of better
`eye of 20/60 orless.
`5. Worse eye with maximal visual acuity (cor-
`rected) less than 20/200; grade 4 plus maximal
`acuity of better eye of 20/60orless.
`6. Grade 5 plus maximalvisual acuity of better
`eye of 20/60 orless.
`V. Unknown.
`X. Is added to grades 0 to 6 for presence of tem-
`poralpallor.
`
`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.
`
`Appendix B. ExpandedDisability Status Scale
`(EDSS)
`
`0 = Normal neurologic exam (all grade 0 in Func-
`tional Systems [FS]; Cerebral grade 1 accept-
`able).
`
`1.0 = No disability, minimal signs in one FS (ie,
`grade 1 excluding Cerebral grade 1).
`
`1.5 = Nodisability minimal signs in more than one
`FS (more than one grade 1 excluding Cerebral
`grade1).
`
`3.0 = Moderatedisability 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 moderatedisability
`in one FS (one grade 3) and one or 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
`FSgrade 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
`muchof the day, able to work a full day, may
`otherwise have somelimitation of full activity
`or require minimalassistance; characterized
`by relatively severe disability, usually consist-
`ing of one FS grade 4 (others 0 or 1) or combi-
`nations of lesser grades exceeding limits of
`previous steps. Able to walk withoutaid orrest
`for some 300 meters.
`
`5.0 = Ambulatory without aid or rest for about 200
`meters; disability severe enough to impairfull
`daily activities (eg, to work full day without
`special provisions). (Usual FS equivalents are
`one grade 5 alone, others 0 or 1; or combina-
`tions of lesser grades usually exceedingspecifi-
`cations 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 combina-
`tions 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 = Constantbilateral assistance (canes, crutches,
`or braces) required to walk about 20 meters
`without resting. (Usual FS equivalents are
`combinations with more than two FS grade
`38+.)
`
`November 1983 NEUROLOGY33 1451
`
`8
`
`

`

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`ww
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`. Kurtzke JF, Berlin L. Isoniazid in treatment of multiple
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