NURS 2003H Chapter Notes - Chapter 61: Cyclophosphamide, Methotrexate, Interferon Beta-1B
26 Jun 2018
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Multiple Sclerosis CH 61 p. 1715-1718
- A chronic, progressive, degenerative, autoimmune disorder of the CNS characterized by
disseminated (spread or disperse widely) demyelination of nerve fibers of the brain, the
spinal cord, and the optic nerves.
- Canadians have the highest rates of MS in the world; more than 3 Canadians are
diagnosed each day.
- Higher prevalence rates in areas with temperature climates and lower prevalence rates in
warmer climates.
- A disease of young to middle-aged adults, with the onset usually being 15-50 years of age
- Women are affected more (ratio 3:1).
- Geography, ethnicity, and other factors interact in a very complex way to cause MS.
- MS may be triggered by environmental factors in individuals with genetic susceptibility
see more in females.
Etiology and Pathophysiology
- Cause unknown
oResearch suggests that MS may be related to environmental and infectious (viral)
factors, dietary deficiencies (vit D), and immunological and genetic factors and is
perpetuated because of intrinsic (inherited) factors (i.e. faulty immunoregulation).
- First, second and third degree relatives of patients with MS are at higher risk, multiple
genes confer this.
- Precipitating factors: infection, trauma, emotional stress, excessive fatigue, pregnancy,
and a state of poor health.
oControversial, may be a random association with no cause-and-effect relationship
- MS is characterized by chronic inflammation, demyelination (myelin sheath of neurons is
damaged), and gliosis (scarring) in the CNS.
- The primary neuropathological condition is an autoimmune disease orchestrated by
autoreactive T cells (lymphocytes).
oMay initially be triggered by a virus in genetically susceptible individuals
oThe activated T cells in the systemic circulation migrate to the CNS causing
blood-brain barrier disruption.
This is likely the initial event in the development of MS
- Subsequently, an antigen-antibody reaction within the CNS results in activation of the
inflammatory response and, through multiple effector mechanisms, leads to
demyelination of axons.
- The disease consists of loss of myelin, disappearance of oligodendrocytes (type of
neuroglia provides support and insulation to axons), and proliferation of astrocytes (a star
shaped glial cell of the CNS).
oResults n characteristic plaque formation or sclerosis, with plaques scattered
throughout the CNS.
- Initially, the myelin sheaths of the neurons in the brain and spinal cord are attacked.
oEarly in the disease, the myelin is damaged, but the nerve fibers are not and the
nerve impulses are still transmitted.
oPatient may complain of weakness and slight impairment of function.
oMyelin sheath can regenerate and symptoms disappear resulting in remission.
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- The axon also becomes involved in later stages of the disease. Myelin is replaced by glial
scar tissue, which forms hard, sclerotic plaques in many regions of the CNS.
oWithout myelin, nerve impulses slow down, and with destruction of nerve axons,
impulses are totally blocked, resulting in permanent loss of function.
oChronic lesions, demyelination continues with progressive loss of nerve function.
Clinical Manifestations
- The onset is insidious (sneaky), with vague symptoms that occur intermittently over
months or years.
- May not be diagnosed until long after the onset of the first symptom.
- The disease process has a spotty distribution in the CNS, so the signs and symptoms vary.
- Chronic, progressive deterioration in some persons and remissions and exacerbations in
others.
- Progressive scarring of the myelin sheath occurs, and the overall trend is progressive
deterioration in neurological function.
- Clinical manifestations vary according to the areas of the CNS involved.
oSevere, long-lasting symptoms early during the disease
oOccasional and mild symptoms for several years after onset.
- Common S&S: motor, sensory, cerebellar, and emotional problems.
oMotor symptoms weakness or paralysis of limbs, the trunk, or the head;
diplopia (double vision); scanning speech; and spasticity of the muscles that are
chronically affected.
oSensory numbness and tingling, other paresthesia (pins and needles), patchy
blindness (scotomas), blurred vision, vertigo, tinnitus (ringing in the ears),
decreased hearing, and chronic neuropathic pain.
Radicular (nerve root) pains may be present, particularly in the low
thoracic and abdominal regions.
Lhermitte’s sign: transient sensory symptom described as an electric shock
radiating down the spine or into the lower limbs with flexion of the neck.
oCerebellar nystagmus (involuntary eye movement), ataxia (lack of muscle
control during voluntary movements like walking), dysarthria (muscles used for
speaking are weak, slurred speech), dysphagia (difficulty swallowing).
oSevere fatigue causes significant disability in some patients, associated with
increased energy needs, deconditioning, depression, medication adverse effects.
oBowel and bladder function can be affected if the sclerotic plaque is in areas of
the CNS that control elimination.
Constipation, spastic (uninhibited) bladder which indicates a lesion above
the second sacral nerve which cuts off suprasegmentally inhibiting
influences on bladder contractility, as a result the bladder has a small
capacity and its contractions are unchecked- dribbling, incontinence.
Flaccid (hypotonic) bladder: indicates a lesion in the reflex arc governing
bladder function. The bladder has a large capacity for urine because there
is no urge to void, no pressure, and no pain.
A combination of the two previous problems can occur.
oSexual dysfunction may occur.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
A chronic, progressive, degenerative, autoimmune disorder of the cns characterized by disseminated (spread or disperse widely) demyelination of nerve fibers of the brain, the spinal cord, and the optic nerves. Canadians have the highest rates of ms in the world; more than 3 canadians are diagnosed each day. Higher prevalence rates in areas with temperature climates and lower prevalence rates in warmer climates. A disease of young to middle-aged adults, with the onset usually being 15-50 years of age. Geography, ethnicity, and other factors interact in a very complex way to cause ms. Ms may be triggered by environmental factors in individuals with genetic susceptibility see more in females. Cause unknown: research suggests that ms may be related to environmental and infectious (viral) factors, dietary deficiencies (vit d), and immunological and genetic factors and is perpetuated because of intrinsic (inherited) factors (i. e. faulty immunoregulation).
