Most people with MS experience an increase in physical disability (The loss of abilities that results from damage to the central nervous system as MS progresses and may be irreversible1) at some point in time.2 When it happens, what kind of disability it is and how much it changes differs for everybody. The graphs below show how disability progression can vary between individuals.
Disability worsening related to relapse, with or without complete recovery.
Disability worsening related to relapse without complete recovery, followed by disability progression independent of relapses.
Disability progression independent of relapse.
In MS, the immune system attacks nerve cells in the brain, spinal cord and optic nerves.3 This disease activity can cause symptoms and disability.
There are two main types of disease activity:
Such as a relapse
(New or worsening signs and symptoms caused by inflammation in the central nervous system. These episodes develop quickly, last at least 24 hours and can continue for several days to weeks. Relapses can be followed by a full recovery or some continuing disability)4
Detected with MRI brain scans
(Scans that show lesions or damaged areas of the brain)
Physical disability gets worse (progression) when disease activity causes more and more nerve cells to die (neurodegeneration).5
People may experience disability in different ways, depending on what part of the brain, spinal cord or optic nerves is affected.6
Disability is measured in different ways.
Measures the degree of physical disability based on a neurological exam of seven functional systems throughout the body, plus a person’s walking ability. The EDSS and its predecessor DSS have been used in nearly every MS clinical trial in the last 40 years.7
A composite endpoint that measures the proportion of people with no confirmed progression of disability status (EDSS), walking speed (T25-FW) and upper extremity function (9-HPT) and may represent a new outcome for people with PPMS.
Measures arm, wrist and hand function by timing the speed in which a person can move nine pegs into nine holes and then remove them, using one hand at a time.8
Determines walking speed by measuring how fast a person with MS can walk 25 feet.9
Disease activity and disability progression can occur at the earliest stage of the disease.10 So one of the goals of MS treatment is to control disease activity as early as possible.
Slide over to the next image to show an example of early treatment with a disease-modifying treatment (DMT)
Early treatment with an effective DMT may reduce disease activity and disability progression.11
Giovannoni, G, et al. Brain Health: Time Matters in Multiple Sclerosis. 2015; pp 14.
MS International Federation. What is MS? Available at
Medline Plus. Multiple Sclerosis. Available at
National MS Society. Managing Relapses. Available at
De Stefano N., et al. Evidence of Axonal Damage in the Early Stages of Multiple Sclerosis and Its Relevance to Disability. Arch Neurol. 2001;58(1):65-70. Available at
National MS Society. MS Symptoms. Available at
National MS Society. Functional Systems Score (FSS) and Expanded Disability Status Scale. Available at
National MS Society. 9-Hole Peg Test (9-HPT). Available at
National MS Society. Timed 25-Foot Walk (T25-FW). Available at
MS Brain Health. Time Matters in Multiple Sclerosis. Available at
MS Coalition. The Use of Disease-Modifying Therapies in Multiple Sclerosis: Principles and Current Evidence. Available at
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