Causes of Multiple Sclerosis

Brain

Optic Nerve

Spinal Cord

The initial trigger for development of MS is unknown, but it is likely a complex interaction of genetic susceptibility, environmental exposure, and other factors. Once the disease is established, it continues of its own accord, driven by the immune system’s attack on healthy tissue. MS is widely accepted as being an autoimmune disease, one in which the immune system attacks the nerve-insulating myelin that coats nerve fibers and enables them to function normally. The damage caused by MS results from inflammation in the brain, optic nerves, or spinal cord (collectively the central nervous system, CNS).

Symptoms of MS

Cognitive Impairments

Difficulties with concentration, attention, memory and poor judgment are experienced by approximately half of all people with MS, but such symptoms are frequently overlooked. These can cause difficulties at work and are a major contributor to lost employment.

Depression

This is the most common emotional disorder affecting MS patients. Depression is either caused by the symptoms and uncertainty of MS, or it can be caused directly by MS itself. Most cases of MS-related depression respond to treatment the same way depression does in the general population.

Vision Problems

These are often an early sign of MS. They are the first symptom for approximately 15 percent of patients. This can be experienced as blurred vision, diminished color vision (especially for red), or even blindness in one eye.

Heat Sensitivity

In about 60 percent of MS patients, heat, whether generated by temperatures outside the body or by exercise, may cause temporary worsening of many MS symptoms. In these cases, eradicating the heat eliminates the problem.

Bladder Dysfunction

This is seen in more than 80 percent of people with MS. Problems with bowel function and sexual function can also be caused by MS.

Numbness or Tingling

A numb or tingling feeling in the face, body, arms, or legs is a common first sign of MS in many patients who are eventually diagnosed with the disease.

• Cognitive Impairments

  Difficulties with concentration, attention, memory and poor judgment are experienced by approximately half of all people with MS, but such symptoms are frequently overlooked. These can cause difficulties at work and are a major contributor to lost employment.

• Depression

  This is the most common emotional disorder affecting MS patients. Depression is either caused by the symptoms and uncertainty of MS, or it can be caused directly by MS itself. Most cases of MS-related depression respond to treatment the same way depression does in the general population.

• Vision Problems

  These are often an early sign of MS. They are the first symptom for approximately 15 percent of patients. This can be experienced as blurred vision, diminished color vision (especially for red), or even blindness in one eye.

• Heat Sensitivity

  In about 60 percent of MS patients, heat, whether generated by temperatures outside the body or by exercise, may cause temporary worsening of many MS symptoms. In these cases, eradicating the heat eliminates the problem.

• Fatigue

  This is the most common symptom reported by MS patients. Fatigue can take the form of muscles that weaken rapidly with activity, a lack of energy to complete the day's activities or a persistent desire to sleep or rest. It is seen in up to 80 percent of patients.

• Bladder Dysfunction

  This is seen in more than 80 percent of people with MS. Problems with bowel function and sexual function can also be caused by MS.

• Numbness or Tingling

  A numb or tingling feeling in the face, body, arms, or legs is a common first sign of MS in many patients who are eventually diagnosed with the disease.

Diagnosis

There is no single test that unequivocally detects MS. When faced with a patient whose symptoms, neurological exam results and medical history suggest MS, physicians use a variety of tools to look for evidence of MS disease activity while also performing a series of lab tests to rule out other disorders that can mimic MS. To diagnose MS, three major criteria must be satisfied:

Primary Testing Tools

MRI

Evidence of MS damage: MRI scans have become the most useful tool for visualizing the damage caused by MS. MRI provides the physician with detailed pictures of the brain and spinal cord, including the lesions caused by MS inflammation. The MRI can, in some instances, also tell the physician if the lesions have recently formed or if they have been present for some time. MRI has vastly shortened the time it takes to make an MS diagnosis. With MRI, many patients are now diagnosed after their first relapse. This has led to earlier diagnosis and initiation of disease modifying treatment for many MS patients.

Ruling Out Simliar Diseases

A number of other diseases may produce symptoms similar to those seen in MS. Other conditions with an intermittent course and MS-like lesions of the brain’s white matter include polyarteritis, lupus erythematosus, syringomyelia, tropical spastic paraparesis, some cancers, and certain tumors that compress the brainstem or spinal cord. Progressive multifocal leukoencephalopathy can mimic the acute stage of an MS attack. Physicians may also consider stroke, neurosyphilis, spinocerebellar ataxias, pernicious anemia, diabetes, Sjogren’s disease, and vitamin B12 deficiency, depending on the patient. Recent reports suggest that the neurological problems associated with Lyme disease may present a clinical picture much like MS. While it can still be difficult for the physician to differentiate between an MS attack and symptoms that can follow a viral infection or even an immunization, our growing understanding of disease mechanisms and the expanded use of MRI is enabling physicians to diagnose MS with more confidence than ever before. Today, most patients who undergo a diagnostic evaluation for MS will be classified as either having MS or not having MS. However, there are still cases where a person may have the clinical symptoms of MS but not meet all the criteria. In these cases, a diagnosis of “possible MS” is used.

Searching for a Definitive Test for MS

Investigators are continuing their search for a definitive test for MS. Research using MRI has yielded several new imaging approaches which may detect the disease earlier and in greater detail than can be done with current standard imaging methods. While these techniques are not yet in use in a widespread basis, in the future they may become commonplace in clinical practice. While standard MRI provides an anatomical picture of lesions, magnetic resonance spectroscopy (MRS) yields information about the brain’s biochemistry; specifically, it can measure the brain chemical N-acetyl aspartate. Decreased levels of this chemical can indicate nerve damage. Magnetization transfer imaging (MTI) is able to detect white matter abnormalities before lesions can be seen on standard MRI scans by calculating the amount of “free” water in tissues. Demyelinated tissues and damaged nerves show increased levels of free (versus “bound”) water particles. Diffusion-tensor magnetic resonance imaging (DT-MRI or DTI) measures the random motion of water molecules. Individual water molecules are constantly in motion, colliding with each other at extremely high speeds. This causes them to spread out, or diffuse. DT-MRI maps this diffusion to produce intricate, three-dimensional images indicating the size and location of demyelinated areas of the brain. Changes in this process can then be measured and correlated with disease progression. Functional MRI (fMRI) uses radio waves and a strong magnetic field to measures the correlation between physical changes in the brain (such as blood flow) and mental functioning during the performance of cognitive tasks. In addition to helping scientists and physicians better understand how MS develops-an important first step in devising new treatments-these approaches offer earlier diagnosis and enhance efforts to monitor disease progression and the effects of treatment.

Treatment

There are a number of unique medications that have been approved to treat relapsing forms of MS in the United States. The UAB MS & Neuroimmunology Clinic prescribes all FDA-approved medications available for the treatment of MS, and participates in ongoing clinical trials regarding available medications and/or potential new treatments.

Oral

• Aubagio (teriflunomide)
• Tecfidera (dimethyl fumarate)
• Gilenya (fingolimod)

Injection

• Avonex (interferon beta-1a)
• Betaseron (interferon beta-lb)
• Extavia (interferon beta-lb) (Generic Betaseron)
• Rebif (interferon beta-la)
• Copaxone (glatiramer acetate)
• Glatopa (glatiramer acetate) (Generic 20 mg dose Copaxone)
• Plegridy (peginterferon beta-la)

Infusion

• Tysabri (natalizumab)
• Novantrone (mitoxantrone)
• Lemtrada (aletuzumab)
• Ocrevus (ocrelizumab)

More information on available medications and considerations can be found on the US Food and Drug Administration (FDA) website. Treatment options should always be discussed with the treating physician in considering the most appropriate options for each individual treatment plan.