You pick up the telephone to call your friend. You dial a number which will, in effect, let the phone know where to send the signals. Except unknown to you, something has worn away the rubber which covers and protects the wires within your phone. Some signals cannot get through, and the ones that do are unclear. As a result your important information does not get conveyed to your friend. This is a circumstance similar to the process that occurs within the body of a person with Multiple Sclerosis. The name itself is revealing: multiple, more than one, and sclerosis, which refers to areas of sclerotic (scarred) tissue.
Multiple sclerosis (MS) is a potentially debilitating disease in which your body’s immune system eats away at the protective sheath that covers your nerves. MS is far more common in countries with temperate climates, including Europe, southern Canada, northern United States, New Zealand and southeastern Australia. The risk seems to increase with latitude and affects noticeably more women than men with the onset of clinical symptoms occurring between 15 and 50 years of age. It is the most common demyelization disease of the central nervous system.
In the United States alone, there are at least 250,000 cases. Although the exact pathogenesis of the disease is unknown, it is believed that the clinical manifestations of multiple sclerosis are the result of an immune reaction consisting of the penetration of the blood-brain barrier (BBB), entrance into the CNS, and recognition of the myelin basic protein (MBP) and proteolipid (PLP) as foreign. The immune system’s attack on these proteins induces the stripping of the protective coating of myelin and then eventual formation of plaques.
These plaques or lesions can be found throughout the central nervous system, but are most prominently found in the white matter, optic nerve, brainstem, spinal cord, and cerebellum. The formation of these plaques causes the conduction of action potentials along the axon to be reduced, resulting in neurocognitive or neuromuscular impairment. Symptoms vary widely, depending on the amount of damage and which particular nerves are affected. People with severe cases of multiple sclerosis may lose the ability to walk or speak.
It can be difficult to diagnose early in the course of the disease, because symptoms often come and go even disappearing for months. Signs and symptoms vary widely, they may include: • Numbness or weakness in one or more limbs, which typically occurs on one side of your body at a time or the bottom half of your body • Partial or complete loss of vision, usually in one eye at a time, often with pain during eye movement (optic neuritis) • Double vision or blurring of vision • Tingling or pain in parts of your body.
• Electric-shock sensations that occur with certain head movements • Tremor, lack of coordination or unsteady gait • Fatigue • Dizziness Clinical symptoms of multiple sclerosis include: optic nerve dysfunction, internuclear ophthalmoplegia, upper motor neuron weakness, tremors, ataxia, sensory disturbances, and autonomic dysfunction. While the typical clinical course of multiple sclerosis is characterized by relapsing and progressive disability, there have been examples of subclinical cases of MS where the diagnosis is confirmed only by the presence of large confluent, demyelization plaques found only upon autopsy.
Diagnosis is difficult, medical history and clinical examination must show at least two separate lesions that have occurred at more than one time. Because of the difficulty of diagnosis, the presence of MS is usually deemed to be definite, probable, or possible. A neurological examination can indicate lesions through the presence or absence of various signs and reflexes. A sign is an abnormality detected through examination, while a symptom is a subjective complaint noted by the patient. There is not necessarily a correlation between symptoms and signs.
Signs may confirm symptoms or they may be asymptomatic. Symptoms may exist in the absence of signs. Computerized tomographic (CT) scans will show some lesions. Magnetic resonance imaging usually reveals many more lesions than the CT scan, including some that may be subclinical, that is, they are not detectable through examination and may have no associated symptoms. An autopsy will usually show many more lesions than were ever suggested by either symptoms or signs. These lesions are probably the result of subclinical attacks of the disease.
Computerized testing of evoked potentials tests the brain’s electrical responses to various forms of stimulation of the eyes, ears, or other parts of the body. Delays in these responses may indicate lesions that are clinically silent producing no symptoms and can sometimes firm up a questionable diagnosis from probable to definite MS. Testing of the cerebrospinal fluid for protein content, the number and type of white blood cells, and the amount of Ig6, a gamma globulin, can also support a diagnosis. Heat and humidity can be a real problem for those with MS, as mentioned earlier.
Damaged nerve fibers have a strongly diminished tolerance for heat. Increases as little as 0. 1° centigrade can decrease conduction or cause blockage, which will result in the appearance of symptoms. The presence and effects of fatigue can be exceedingly difficult to live with and the fatigue of MS is often misunderstood. That phrase “It’s all in your head” is all too easily applied to those who complain of fatigue. And I imagine everyone with MS has heard over and over, “But you look so good,” usually accompanied by an expression, however slight, of astonishment.
The fatigue of MS is special, and has several causes. Demyelinated nerve fibers use more energy to conduct impulses and thus fatigue more easily than normal fibers. Muscles that have been weakened result in a reliance on stronger muscles, which then tire faster. During a relapse a person with MS takes two to three times more energy to walk as would take a normal person over the same distance. Such an increased use of energy obviously results in increased fatigue. There are three primary courses the disease may take: a benign course, this is a sub-group of relapsing/remitting.
It is used to describe the disease in people who have had MS for fifteen or more years without picking up any serious and enduring disability; an exacerbating- remitting course with more early attacks with less complete remission resulting in some disability, followed by long periods of stability; and a progressive course involving a slow and continuing progression of the disease with no remission Patients with MS may suffer urine retention and urinary tract infections, constipation, joint contractures, pressure ulcers, rectal distension, and pneumonia.
As the disease advances, it may cause blindness, ataxia, incontinence, muscle atrophy, spastic paraplegia, hemiplegia, and complete paralysis. No definitive test for MS has been developed, although magnetic resonance imaging (MRI) can identify lesions as the disease progresses. Treatment typically focuses on combating the autoimmune response and managing the symptoms. Some people have such mild symptoms that no treatment is necessary. An enormous amount of research is currently being done on the causes and processes of multiple sclerosis, and understanding of the disease continues to increase.
My aunt was diagnosed with MS and since her life has been on an emotional roller coaster. The most important fact about multiple sclerosis is its unpredictability and its uncertainty. There are very few certainties to be found anywhere in any aspect of this disease. References Bansil, Shalini et al. , “Multiple Sclerosis: Pathogenesis and Treatment,” Seminars in Neurology, 1994 June, 14(2):146-153. Bray, Patrick F. , et al. , “Antibodies against Epstein-Barr nuclear antigen (EBNA) in multiple sclerosis CSF, and two pentapeptide sequence identities between EBNA and myelin basic protein”, Neurology, 1992 September, 42:1798-1804.
Challoner PB et al. , “Plaque-associated expression of human herpesvirus 6 in multiple sclerosis. ” Proceedings of the National Academy of Sciences of the United States of America, 1995 August 1, 92(16):7440-4. Gronning, Marit et al. , “Infections in Childhood Adolescence in Multiple Sclerosis”, Neuroepidemiology, 1993, 12:61-69. Kurtzke, John F. , “Epidemiologic Evidence for Multiple Sclerosis as an Infection”, Clinical Microbiology Reviews, October 1993, 6(4):382-427. Lycke, Jan et al., “Acyclovir treatment of relapsing-remitting multiple sclerosis”, Journal of Neurology, 1996 243:2140224. Oksenberg, Michael, et al. , “Multiple sclerosis: form immunogenics to immunotherapy,” Journal of the Neurological Sciences, 1993, 155(Suppl) S29-S37.
Panitch, Hillel S. , “Influence of Infection on Exacerbations of Multiple Sclerosis”, Annals of Neurology, 1994, 36:S25-S28. Poser, Charles H. , “The Pathogenesis of Multiple Sclerosis”, Journal of the Neurological Sciences”, 1993, 115 (suppl):S3-S15.
Riise, Trond et al., “Clustering of Residence of Multiple Sclerosis Patients at Age 13 to 20 Years in Hordaland, Norway”, American Journal of Epidemiology, 1991 133:932-939. Sola P. et al. , “Human herpesvirus 6 and multiple sclerosis: survey of anti-HHV-6 antibodies by immunofluorescence analysis and of viral sequences by polymerase chain reaction. ” Journal of Neurology, Neurosurgery and Psychiatry, 1993 August, 56(8):917-9. Vaughan, J. H. , et al. , “An Epstein-Barr virus-related cross reactivity autoimmune response in multiple sclerosis in Norway,” Journal of Neuroimmunology, 1996, 69:95-102.