Med-Surg: Chapter 37: Multiple Sclerosis Flashcards
Multiple Sclerosis (MS)
chronic neurological disorder in which the nerves of the CNS (brain and spinal cord) degenerate
- derives its name from the build up of scar tissue (sclerosis) or plaques that for during demyelination (destruction of myelin sheath)
- autoimmune disease; the immune system mistakenly identifies normal body substances and tissues as foreign and attacks them; the immune system attacks the brain and spinal cord (CNS)
Risk Factors
- 20 to 50 years old
- women
- positive family hx
- immunological factors
- viral infections
- higher in colder, more northern latitudes
4 Main types of MS
- Relapsing-remitting
- Secondary progressive
- Progressive relapsing
- Primary progressive
Types of MS: Relapsing-Remitting
- most common form
- characterized by relapses (exacerbations) during which new clinical manifestations appear and old ones worsen or reappear
- relapses can last days or months
- relapses are followed by periods of remission during which the patient has either a partial or total recovery; this can be slow or instantaneous
Types of MS: Secondary Progressive
the patient who initially had relapsing-remitting develops gradual worsening of the disease
- in the early phase, the patient still may experience relapses, but these will progress into a general deterioration
- no real recovery occurs
Types of MS: Progressive relapsing
progressive course with a gradual worsening of clinical manifestations from onset, and the relapses may or may not have recovery
Types of MS: Primary progressive
gradual progression with no remissions
- may be temporary plateaus
- affects women and men equally
- occurs late 30’s early 40s
- initial disease activity is in the spinal cord, not the brain, so these patients less likely to develop cognitive problems
Pathophysiology
- myelin is the protective sheath that covers the spinal cord and nerves; it not only protects the nerve, but it also helps the impulses travel along the nerves at a faster rate; these impulses control muscle movements, as well as transmitting sensory data
- the CNS contains the blood-brain barrier that separates circulating blood from the brain’s extracellular fluid; barrier is composed of tight junctions between endothelial cells in the CNS vessels that restrict the passage of solutes from the bloodstream
- Demyelination is the loss of the myelin sheath; it begins with the breakdown of the blood-brain barrier that allows immune cells (T lymphocytes) to infiltrate and attack the myelin
- in MS, the immune system attacks the brain and spinal cord (CNS)
Demyelination
the loss of the myelin sheath
Clinical Manifestation
the resulting inflammation in MS destroys the myelin, resulting in impaired sensation, movement, and thinking
- nerves can regain myelin, but this occurs more slowly than deterioration in MS
- nerve conduction is slowed or irregular due to loss of myelin that facilitates impulse transmission
> manifestations:
- numbness or weakness in one or more limbs
- partial or complete vision loss, often with pain during eye movement (optic neuritis)
- double or blurred vision
- tingling or pain
- electric-shock sensations that occur with head movements
- tremor, lack of coordination, or unsteady gait
- fatigue
- dizziness
Diagnosis
-no specific test; can be difficult to diagnose
-may not be diagnosed for months to years after onset of clinical manifestations
-diagnosis is made by ruling out conditions with similar presentations
-detailed hx, physical, and neurological examination are performed
-blood samples are sent to the laboratory to r/o other inflammatory or infectious diseases that may have the same clinical manifestations; vitamin B12 and E deficiencies, Lyme titer, antineutrophil antibodies (ANA) for autoimmune diseases, angio-tensin converting enzyme for sarcoidosis, HIV/HTLV (human T-lymphotropic virus), erythrocyte sedimentation rate (ESR) for inflammation, rapid plasma reagin (RPR) for neurosyphilis, anticardiolipin antibodies, and lupus anticoagulant for coagulopathy/vascular conditions
>a lumbar puncture performed to send CSF sample to be tested for abnormal levels of WBC or proteins and help r/o viral infections
-MRI scans for brain lesions (plaques)
-Electrophysiological tests, and evoked potentials to examine how quickly impulses are traveling through the nerves
For a definitive diagnosis
patient must have at least 2 separate symptomatic events or MRI changes in at least 2 separate locations
Treatment
- no cure
- focuses on improving the speed of recovery from attacks, reducing the number of attacks, and slowing the progression of the disease
- lifestyle management: adequate rest, exercise, staying cool, healthy balanced diet, and relieving stress because these can all trigger exacerbation or flare of MS
- physical therapy used to help strengthen muscles and improve daily function
- Betaseron (Interferon beta-1b) modifies/slows the disease process
Medical Management
> First, medications used to modify the disease course; these are used to slow the progression of the disease
- beta interferons: interferon beta-1a (Avonex, Betaseron, and Rebif); interferon beta-1b (Extavia)
- glatiramer (Copaxone)
- fingolimod (Gilenya)
- immunosuppressive agents: natalizumab (Tysabri) and mitoxantrone (Novantrone)
> Second, strategies used to treat attacks include
-corticosteroids and plasma exchange (plasmapheresis) to decrease the inflammatory and immunologic factors involved in the exacerbation
> Final focus, treat clinical manifestations
-muscle relaxants such as baclofen (Lioresal and Kemstro) and tizanidine (Zanaflex) decrease spasticity
> medications may also be prescribed to help reduce fatigue and used to treat depression, pain, and bladder or bowel problems
Medication: Interferon beta-1a (Avonex, Refib)
immunomodulator
- use to modify the disease course; slow the progression of the disease
- alters the immune system by reducing the body’s ability to make antibodies; these antibodies are what attack the myelin; therefore, this slows the attack on myelin and slows disease progression
