All About Multiple Sclerosis

More MS news articles for January 2004

Overview of Multiple Sclerosis

http://www.nationalmssociety.org/ms_nursing/pdf/NursMod_Overview.pdf

December 2003
Nancy J. Holland, EdD, RN, MSCN
MS Nursing - Introduction to Multiple Sclerosis Nursing Care
The National Multiple Sclerosis Society

OBJECTIVES

After reading this article, nurses who are new to the care of people with MS will be able to do the
following:

INTRODUCTION

Multiple sclerosis (MS) is a disease that affects the central nervous system, which includes the brain, spinal cord, and optic nerves. MS is believed to affect approximately 400,000 Americans, typically striking between the ages of 20 and 50. While some persons will have a limited number of “attacks” or “relapses” and remain fairly healthy for decades, others may deteriorate rapidly from the time of diagnosis. MS is, therefore, a variable and unpredictable disease, and poses a complex and unique clinical challenge for healthcare professionals.

PATHOPHYSIOLOGY OF MS

Immune Dysfunction and Damage to CNS

MS is characterized by the formation of multiple lesions along the nerve fibers in the brain and spinal cord. The key players include:

MS is thought to be an autoimmune disease, but what triggers the immune system to attack the body is still unclear. During this immune response, cells that identify antigens are somehow triggered to interpret one of the components of myelin as foreign. When antigen-presenting cells introduce the myelin antigen to the T cells, the T cells pass through the blood brain barrier and mount an attack on the myelin, activating more T cells and other immune cells in the process. Other inflammatory factors, such as cytokines, are released, and the end result is an immunologic cascade that produces tissue damage, not only to the myelin sheath, but to the underlying axons as well.

This “demyelination” makes the transmission of information via axons more difficult. Ultimately, there is interference with the conduction of nerve impulses from the sensory organs to the CNS and from the CNS to the muscles. Injury to the axons themselves, called “axonal injury,” can be part of this destructive process even early in the disease and may result in permanent loss of neuronal transmission.

At least initially, however, the process of MS is typically a waxing and waning one. Inflammatory episodes occur in the form of periodic acute attacks, and once the inflammation subsides, impaired function is usually recovered either completely or partially. Reversal of inflammation or the process of “remyelination” can occur over and over, or, permanent damage may occur at any time (Ludwin, 1988; Stone, Albert, et al., 1995; Stone, Smith, et al., 1995).

Possible Triggers

While MS is almost certainly an autoimmune disease, the factor or factors that trigger an attack on the brain’s white matter remain unknown. A number of hypotheses are being explored, one being the role of viruses. Peripheral blood antibody titers to many viruses are elevated in people with MS. These include varicella zoster, vaccinia, rubella, Epstein-Barr, human herpes virus 6 (HHV-6), and others. In some cases, virus-specific antibody is also detected in the cerebrospinal fluid, and recently some viruses, especially HHV-6, have been detected near the characteristic brain lesions of some persons with MS. The relevance of these findings to the pathophysiology of the disease remains to be determined.

Environmental factors may also be involved. MS occurs more often in countries with a moderate, cool climate than in warmer countries. In both the northern and southern hemispheres, MS is more frequent at greater distances from the equator. This applies to regions within a country itself—in the U.S., the incidence of MS is greatest in the northern states.

More certain is the genetic link seen in MS. MS prevalence rates are quite variable between different ethnic and racial groups, being highest in northern European Caucasians, and lowest in Asians. While no causative gene has been identified, the risk for MS is 10 to 50 times higher for persons with an affected relative than in persons with no family history. The concordance in identical twins is approximately 30%, as compared to 3–5% in fraternal twins. It is likely that multiple genes are involved, and an interaction with an external trigger, such as a virus or environmental factor, may be necessary to initiate disease.

CLINICAL PATTERNS

MS is essentially divided into four main courses (Lublin & Reingold, 1996):

DIAGNOSIS

MS is often suspected on the basis of symptoms. Events that are highly suggestive of MS include gait disturbances, optic neuritis, persistent binocular double vision or numbness. Such symptoms may occur periodically, then disappear for months or years. Several tests are used in the diagnostic work-up:

Newer techniques being used in the research setting are yielding a closer look at the pathophysiology of the brain. With magnetization transfer ratio (MTR), tissue damage is more accurately quantified.

MTR involves delivering energy to protons in the brain and then measuring how much is transferred or absorbed. This technique can reveal damage in brain tissue that appears normal on MRI (Filippi & Rovaris, 2000). Another approach, magnetic resonance spectroscopy, enables investigators to analyze MRI for signals from certain chemicals, such as N-acetyl-aspartate (NAA). NAA is found largely in axons; low levels are felt to signify axonal injury (Viala et al., 2000).

CONFIRMING THE DIAGNOSIS

The International Panel on MS Diagnosis has recently revised the criteria for diagnosis of MS (McDonald et al., 2001), which integrates MRI findings with clinical and paraclinical diagnostic methods and takes into account a variety of presentations. To receive a diagnosis of MS, patients must demonstrate lesions separated in time and space, i.e. more than one lesion in more than one location occurring at more than one point in time.

Once a diagnosis of relapsing MS has been confirmed, treatment with injectable immunomodulating agents is generally recommended. These agents have been shown to reduce the frequency of relapses by about one third and are believed to slow the progression to disability. This will be further described in the next module, “Disease Modification.”

Disease-modifying agents offer hope to MS patients; however, studies are still lacking that will validate their sustained ability to prevent disability over time. Other forms of treatment include symptom management and treatment of acute relapses.

CLINICAL SIGNS AND SYMPTOMS

The clinical symptoms and deficits are quite varied among persons with MS, and they typically change (and worsen) as the disease evolves. The most frequent (which will be discussed in greater detail in other modules) include (Van den Noort & Holland, 1999):

MODELS OF CARE IN MS

The spectrum of MS requires a wide array of professional services throughout the person’s lifetime.

Many types of healthcare professionals are involved, ranging from neurologists to nurses to neuropsychologists and social workers. The challenge is to sustain a level of support to meet individual and family needs throughout a lifetime, keeping in mind the goals of MS care: disease stabilization, wellness, maximal function and independence, and maintenance of productivity and a meaningful place in society.

SUMMARY

MS is a chronic, progressive and essentially incurable disease that most often affects young adults. It is thought to be an autoimmune diseases that affects the central nervous system. The course of MS is unpredictable and variable on a day-to-day and an individual patient basis. As chronic problems accumulate, the disease may become more steadily progressive, with fewer or no acute relapses. A diagnosis of MS is a clinical one based on a thorough history and neurologic examination, and supported by MRI and other diagnostic tests. Management strategies fall into three general categories: acute treatment of relapses, prevention of progression or reduction in the frequency of relapses, and control of specific symptoms.

REFERENCES

Filippi M, Rovaris M. Magnetization transfer imaging in multiple sclerosis. J Neurovirol 2000 May;6 Suppl 2:5115–5120.

Lublin FD, Reingold SC. Defining the clinical course of multiple sclerosis: results of an international survey. Neurology 1996;46:907–911.

Ludwin SK. Remyelination in the central nervous system and the peripheral nervous system. Advances in Neurology: Functional Recovery in Neurological Disease. New York: Raven Press, 1988:47.

McDonald WI, et al. Recommended diagnostic criteria for multiple sclerosis: guidelines from the International Panel on the Diagnosis of Multiple Sclerosis. Ann Neurol 2001;50(1):121–127.

Stone LA, Smith ME, et al. Blood-brain barrier disruption on contrast-enhanced MRI in patients with mild relapsing-remitting multiple sclerosis: relationship to course, gender and age. Neurology 1995;45(6):1122–1126.

Stone LA, Albert PS, et al. Changes in the amount of diseased white matter over time in patients with relapsing-remitting multiple sclerosis. Neurology 1995;45(10):1808–1814.

Van den Noort S, Holland NJ. Multiple Sclerosis in Clinical Practice. New York: Demos, 1999.

Viala K, et al. Magnetization resonance spectroscopy in multiple sclerosis. Rev Neurol (Paris) 2000;156(12):1078–1086.

REVIEW EXERCISE

1. The underlying pathophysiological nature of MS is

a. Viral
b. Autoimmune
c. Genetic
d. Bacterial
2. Which factor or factors influence the diagnosis of MS?
a. Patient history and pattern of symptoms
b. Neurological findings
c. MRI findings
d. Visual evoked potential studies
e. All of the above
3. How are the immunomodulating agents administered?
a. Orally
b. Subcutaneously
c. Intramuscularly
d. B and C, depending on the agent
4. MS usually begins as a relapsing-remitting disease, with acute episodes followed by months of remission.
a. True
b. False
5. What is the recommended time point for prescribing immunomodulating agents?
a. Upon a diagnosis of “possible MS”
b. Upon a definite diagnosis of relapsing-remitting MS
c. After the patient progresses to moderate disability
d. Any time a neurologist deems necessary
Answers: 1 b; 2 e; 3 d; 4 a; 5 b
 

Copyright © 2003, The National Multiple Sclerosis Society