Multiple Sclerosis Flashcards
Multiple Sclerosis
A condition in which demyelination of the nerve occurs. Demyelination results in scar tissue formation that affects nerve transmissions in widely scattered areas of the brain and spinal cord
MS begins with
an inflammatory process, followed by the loss of myelin that surrounds the nerve axons. Scar tissue, known as sclerotic plaques, develops at the sites of demyelination. These plaques cause a slowing, disruption or blockage of nerve transmissions. With increased plaque formation, symptoms become more severe.
This disease strikes people during
a very active time in life. The average age of onset is between 20 and 40 years, although it can occur as early as 15 and as late as 45.
Women are slightly more affected than men
causes multiple sclerosis
Genetic factor
A genetic link is present. Thought to be polygenic. Has been found in 25% to 30% of monozygotic twins. There also seems to be a risk to relatives of affected individuals
Environmental factor
This condition is most prevalent in temperate climates, such as North America and Northern Europe. Therefore, the closer one is to the equator the less likely one is to get MS
Viral factor
Some researchers believe that a virus is responsible for stimulating overactivity of the immune response. This overactivity results in the demyelination of the axons.
Immunological factor
The overactivity of certain types of white blood cells leads to attacks on the myelin as if it were a foreign substance. Susceptibility to this autoimmune disorder is thought to be, in part, genetically predisposed
Types of MS
Classified by progression of symptoms
Relapsing-Remitting Benign Clinically Isolated Syndrome Primary progressive Secondary progressive Progressive relapsing
Relapsing Remitting MS (RRMS)
characterized by unpredictable but clearly defined episodes during which new symptoms appear, or existing ones get worse. These ‘episodes’ are also known as attacks, exacerbations, or flare-ups. Typically attacks come on over a few hours to a few days, and last anywhere from at least 48 hours to a few months. The hallmark of RRMS is the recovery, or ‘remission’ that occurs between attacks. In the period between attacks, recovery is complete , or nearly complete to pre-attack function, and this recovery persists for a clear period of time. The time between attacks is variable but can be months or even years. About 85% of people have RRMS at the time of diagnosis.
Benign MS
in which remission between relapses is almost complete such that 15 – 20 years after diagnosis, there is little if any accumulation of physical disability. In most cases of benign MS, symptoms mainly affect the senses of sight and/or touch
Clinically Isolated syndrome (CIS)
refers to a single episode of neurological symptoms. This is also sometimes referred to as probable MS. Often, on investigation using MRI and/or evoked potentials, the doctor finds laboratory evidence of a second attack which then defines RRMS. In very early MS, it may be necessary to follow things and repeat investigations a few months later to find evidence of a second defining MS attack.
Primary Progressive MS (PPMS)
describes a course of MS which is characterized by a slow accumulation of disability, without relapses (figure 2a). It may stabilize for periods of time, and even offer minor temporary improvement (figure 2b), but overall, there are not periods of remission in PPMS. Approximately 10% of people diagnosed with MS have PPMS and it is the only form of MS to affect men and women equally. PPMS tends to be diagnosed after age 40
Secondary Progressive MS (SPMS)
follows on a course of RRMS. Over time, distinct relapses and remissions become less apparent and the disease begins to worsen steadily (figure 3a). Occasional flare-ups, minor improvements, and even periods of stability may occur, but overall, the picture is one of accumulating disability (figure 3b). About 50% of people with RRMS will develop SPMS within 10 years of diagnosis. There is not yet reliable long term data available on the impact of disease modifying therapy and conversion to SPMS.
Progressive Relapsing MS (PRMS)
is the rarest course of MS, occurring in only about 5% of people diagnosed. People with this form of MS experience steadily worsening disease from the beginning, but also experience clear attacks of symptoms, with (figure 4a) or without recovery (figure 4b). They do not experience remissions in the sense that patients with RRMS do. Sometimes patients with this form of MS are originally diagnosed with PPMS, then experience an acute attack, establishing the diagnosis of PRMS
Criteria for diagnosis
Multiple sclerosis is difficult to diagnose in its early stages
The history and neurological exam are the mainstay of diagnosis in MS.
When diagnosing MS, doctors are looking for evidence of the lesions in the central nervous system caused by MS. Sometimes these lesions cause symptoms and the doctor can determine the location of the lesion by the symptoms it is presenting on physical examination. Sometimes lesions occur but don’t cause symptoms, and doctors use MRI and evoked potential testing to determine their location. MRI can also be helpful in showing lesions that have developed at different times.
The history and neurological exam are the mainstay of diagnosis in MS. MRI, evoked potentials and very occasionally lumbar puncture, are tests that may be useful in confirmation when a diagnosis of MS is suspected.
Symptoms
The specific symptoms that each person experiences with MS will vary according to the location of the lesion in the CNS and the extent of that lesion.
In particular the white matter is affected
Lesions are commonly found in the brainstem, cerebellum and spinal cord
Some cranial nerves can also be involved, namely the optic nerve and the trigeminal nerve. Lesions of the optic nerve can result in the loss of visual acuity and in colour blindness, visual field defects and diplopia. Total blindness is unco.mmon. Lesions of the trigeminal nerve result in trigeminal neuralgia
Fatigue
Spasticity
Weakness
Impaired proprioception
Intention tremors
Circumducted gait
Altered posture
Compensatory changes of unaffected or overused limbs
Paresthesia
Cold extremities or sweating abnormalities
Edema, may be present
Mood swings, depression, euphoria, cognitive problems i.e. forgetfulness and inattentiveness
Vertigo
Diplopia, nystagmus, decreased visual acuity, reduced visual field and colour blindness
Speech disturbances i.e. dysarthria and slurring
Bladder dysfunction and secondary to this UTI’s
Bowel dysfunction
Some Factors Exacerbate Symptoms
Vitamin/mineral and essential fatty acid deficiencies
Amalgam dental fillings
Food allergies to dairy products and increased intake of polyunsaturated fats
Stressful events, overexertion, heat, fever, injury and emotional upset
