Multiple sclerosis (MS) is a chronic neurological disease of the central nervous system (CNS). MS is an inflammatory autoimmune disease that damages the myelinated axons in the CNS, resulting in the myelin being fragmented and leading to exposed axons. While the disease course of MS has high variability and is unpredictable, for most patients the disease begins with episodes of reversible neurological deficits, and is then frequently followed by progressive neurological deterioration over time.1
Although the etiology of MS is not well understood, environmental, genetic, metabolic, and immunological factors are thought to have a role. The cardinal pathological features of MS are plaques in the CNS composed of inflammatory cells, demyelinated and transected axons, reduced oligodendrocyte numbers, and gliosis. A wide range of neurological symptoms that arise from various areas of the CNS are the result of these pathological changes.2
Goals of therapy for MS include slowing disease progression, and managing relapses and symptoms.3 Treatment paradigms are evolving from traditional fixed approaches to individualized plans.4
Immune and glial cell subtypes and their contributions to the pathogenesis of MS2
Signs & Symptoms
Signs and symptoms of MS can vary greatly between patients and over time, depending on the extent and location of myelin damage. More common symptoms of MS include:5,6
Patients with relapsing-remitting MS (RRMS), the most common disease course, experience periods of relapse during which new or recurring symptoms develop over days or weeks. These exacerbations alternate with periods of remission during which patients partially or completely recover. Patients with primary-progressive or secondary-progressive MS, however, experience more steady progression of disease, often accompanied by problems with mobility and gait.6,7
These factors may increase a person’s risk of developing MS.6,8
Disease & Clinical Trial Tools
There are many assessment tools which may help clinicians better document and manage their MS patients' symptoms. While the list below is not intended to be comprehensive, it represents many of the tools commonly used in rehabilitation assessment of patients with MS.
The Expanded Disability Status Scale (EDSS) is used to rate neurologic impairment in MS. The EDSS total score ranges from 0 to 10, with scores below 4.5 reflecting a high degree of ambulatory ability and progressively higher scores reflecting loss of ambulatory ability.
Functional system (FS) grades are key to the EDSS, especially within the lower scores of the scale. The eight functional systems assessed are pyramidal, cerebellar, brain stem, sensory, bowel and bladder, visual (or optic), cerebral (or mental), and other. Each system is graded on a scale of 0 to 5 or 6, with 0 representing normal function. The only exception is the “other” system, which shows the presence or absence of other neurologic findings attributed to MS through a grade of 1 or 0, respectively.
The EDSS score is determined through the evaluation of FS grades and ambulatory ability, as presented in the table.9
Multiple Sclerosis Quality of Life-54 (MSQOL-54) measures health-related quality of life (HRQOL) in MS patients through self-reported scoring of 54 items. Of these items, 52 assess 12 dimensions of HRQOL, including physical function, role limitations (physical), role limitations (emotional), pain, emotional well-being, energy, health perceptions, social function, cognitive function, health distress, overall quality of life, and sexual function. The remaining two items assess change in health status and satisfaction with sexual function.
Items are then averaged within related categories to produce associated scale scores with values ranging from 0-100; higher values indicate better quality of life. Weighted combinations of scale scores create two composite scores, physical health and mental health, as shown in the tables.
The Multiple Sclerosis Functional Composite (MSFC) is a clinical outcome measure that assesses arm, leg, and cognitive function through the use of the nine-hole peg test (9HPT), timed 25-foot walk (T25FW), and 3-minute Paced Auditory Serial Addition Test (PASAT-3), respectively.11
The following components compose the MSFC score:12
Not only does change in the MSFC score correlate with change in the Expanded Disability Status Scale (EDSS), but it has been shown to be predictive of subsequent change in EDSS, suggesting increased sensitivity.11
Magnetic resonance imaging (MRI) is an important tool not only in the diagnosis of MS but also in the monitoring of disease progression and treatment efficacy. MRI findings are often used as outcome measures for efficacy-focused clinical trials focusing on changes in the presence and appearance of T1 hypointense and T2 hyperintense lesions to assess optimal treatment response.13
Different MRI scan types may be used for assessments, including:14