Additional Evaluative Tools for Multiple Sclerosis
MS Evaluative Tools Overview
Additional tools are available to measure disease activity. These help to evaluate disease progression as well as changes in specific symptoms, such as fatigue, strength, mobility, vision, cognition, and others. These tools include:
- Expanded Disability Status Scale (EDSS)
- Functional System (FS), aka Functional System Score (FSS)
- MS Functional Composite (MSFC)
- Timed 25-Foot Walk (T25-FW)
- 9-Hole Peg Test (9-HPT)
- Paced Auditory Serial Additions Test (PASAT)
Through these universally accepted systems of measurement, physicians can record their patients’ presenting condition and subsequent improvements, relapses, or disease progression. These systems are particularly valuable in clinical trials, which test the effectiveness and safety of experimental treatments for MS, prior to their approval by the United States Food and Drug Administration (FDA).
Expanded Disability Status Scale (EDSS)
The most widely known scale within the MS community is the Kurtzke Expanded Disability Status Scale (EDSS). Dr. Kurtzke first introduced this system in 1955 as the Disability Status Scale (DSS). It used whole numbers from one to 10 to measure a person’s degree of disability, largely in terms of mobility. To make the measurements more sensitive, Kurtzke later “expanded” the scale by adding half-points between the numbers.
Functional System (FS)
The EDSS is used in conjunction with Kurtzke’s Functional System (FS), also referred to as Functional System Score (FSS). This measures the function of seven major systems in the central nervous system (CNS), plus a section for “other,” each relating to the different areas of functioning that can be affected by MS. These include areas of function such as movement, sensory, bowel and bladder, vision, cognition, etc., and are graded on a scale of 0 (normal) to 6 (severe).
How the EDSS and FS Work Together
Having the ability to evaluate patients, beginning with the first appointment and continuing throughout each person’s journey with MS, is critical to providing the best care and prescribing the most appropriate treatments. The Kurtzke Expanded Disability Status Scale (EDSS) uses full and half-points from 0 to 10 to give neurologists an exact number to apply to one’s current set of abilities as well as reductions in function.
The lower levels of the EDSS – ranging from 1.0 to 4.5 – correspond to individuals whose mobility is largely unaffected by MS and who have a high degree of ambulatory ability. For those within this range, the EDSS score is completely determined by FS scores. As difficulties in movement increase, EDSS scores of 5.0 to 9.5 are applied. These latter scores are determined by movement and gait, with little to no reliance on the FS scores.*
*Multiple Sclerosis Centers of Excellence, US Department of Veterans Affairs
The MS Functional Composite (MSFC)
A newer measurement system that was developed after the introduction of the EDSS and the FS, is the MS Functional Composite (MSFC). This uses three tests to evaluate function:
- Timed 25-Foot Walk (T25-FW), which measures lower extremity function by timing the participants as they walk 25 feet as quickly and safely as possible. It is often done twice and an average of the two scores is given.
- 9-Hole Peg Test (9-HPT), which measures upper extremity function as the participant is timed while using one hand to place pegs into, and remove pegs from, a board with nine holes.
- Paced Auditory Serial Additions Test (PASAT), which measures cognitive function as the participant hears numbers at a set pace and must add the last number heard with the one preceding it.
Other Tests to Evaluate Mobility and Balance
Several scales and tests may be used to assess one’s level of function when experiencing issues with mobility and balance. To follow are four additional commonly used tools:
Timed Up and Go (TUG)
This test helps to evaluate mobility by timing how long it takes someone to get up from a chair, walk 10 feet, turn around, walk back, and sit back down in the chair. Individuals may be observed for walking problems during their walk, such as loss of balance, short strides, and shuffling, which can indicate the need for more testing.
Berg Balance Scale (BBS)
This tool evaluates a person’s balance. When doing this assessment, the patient is asked to perform 14 tasks, each of which is scored from 0 to 4. Tasks include things such as standing up with eyes closed and turning around in a complete circle. At the end of the test, the total of the scores added together provides a number that is used to determine one’s risk of falling and if added support is needed for safety.
Functional Reach Test (FRT)
This test evaluates one’s stability. It looks at how far someone can reach while standing in a fixed position and leaning forward. A modified version looks at how far someone can reach while sitting.
Four Square Step Test (FSST)
This test evaluates balance and coordination by timing individuals as they step in sequence over objects (often two canes placed on the floor) in a “plus-shaped” position. In addition to timing one’s speed while performing the sequence of steps, the participant’s ability to move forward, backward, and to the side, is observed.
Future MS Evaluative Tools
While certainly very useful, our current tools are imperfect, and they are particularly imperfect in assessing progression. Researchers continue to fine-tune and develop new and improved tools for assessing the effects of MS. We await a new generation of tools!