Multiple sclerosis Flashcards
What is the neuropathology underlying MS?
MS occurs when a dysregulated immune system is directed against the myelin of the CNS. In affected areas, there may be demyelination, associated gliosis, and axonal damage. Gray matter can be affected, but to a lesser extent than white matter.
Who does MS affect?
Primarily young adults between ages 20-40, with mean age of 30. There is a genetic link. 1st degree relatives of patients with MS are 6 to 8 times more likely to develop MS. More women are affected by MS than men. However, men are more likely to have more destructive lesions and greater cog impairment than women. MS is more common in White ppl of Northern European descent than in others. However, minorities are more likely to have poorer disease course than Whites. Rates of MS are lowest near the equator.
What is mortality of individuals with MS?
Majority of patients (90-95%) have an average life expectancy.
What are determinants of MS severity?
1) as mentioned previously, male sex and minority status may be associated with more harmful course.
2) younger age of onset is associated with lower relapse rate and slower overall rate of disease progression.
3) lower vitamin D associated with higher relapse rate in MS patients
4) when women with MS become pregnant, they tend to experience fewer relapses and may even experience improvement in overall functioning
How do you diagnose MS?
MS is usually a diagnosis of exclusion because it is so heterogeneous in presentation. There is no single, definitive laboratory test for MS. The newest McDonald criteria (2010) are used for dx MS.
What are the McDonald criteria?
1) There must be evidence of CNS lesions that are disseminated across both space and time.
2) The patient must have 2 or more objective clinical attacks with positive MRI findings
3) Dissemination of lesions in space can be demonstrated in at least one T2 lesion in 2 of 4 areas in the CNS: periventricular, juxtacortical, infratentorial, and/or spinal cord.
What are the most common initial complaints of MS?
Motor and sensory changes.
1) Optic neuritis. Inflammation of the optic nerve results in blurring of vision. Tends to occur unilaterally.
2) Somatosensory changes, including parasthesias - numbing and tingling.
3) Bladder and bowel dysfunction.
4) Cerebellar/brainstem effects - ataxia, dysarthria, and diplopia (double vision)
5) Fatigue - usually the most disabling symptom. Often exacerbated by heat.
6) Sleep disorders are common, including insomnia, sleep-disordered breathing, and restless legs.
What is it called when a patient does not have any positive neuroimaging findings, but has clinical symptoms resembling MS?
Clinically isolated syndrome
What are the 4 different disease courses in MS?
1) Relapsing remitting MS (RRMS): this is the msot common initial dx. There is distinct development of neurologic symptoms followed by variable recovery of function (from remission to complete recovery). There are periods of stability and improvement between relapses.
2) Secondary - progressive - Initially presents as RRMS but is followed by progressive worsening relative to baseline functioning between attacks with no periods of remission. Half of individuals with RRMS will convert to secondary progressive type. Generally associated with greatest deficits in cognitive functioning.
3) Primary - progressive - Continuous gradual worsening of functions from the onset with minor fluctuations, but no distinct exacerbations or periods of remission. Mobility difficulty, such as stiffness or weakness, is the most commong symptoms. More likely to occur in older individuals.
4) Progressive-relapsing - Progressive deterioration of function from onset by punctuated by distinct acute exacerbation or relapses. Periods between relapses are marked by gradual deterioration.
What are treatments for MS?
1) Prednisone for acute relapses
2) disease modifying therapies (DMTs) may also be used to delay relapses, slow disease progression.
What are other disorders to rule out that may also impact white matter?
Leukodystrophy
progressive multifocal leukoencephalopathy
Lupus, and other systemic autoimmune diseases such as Sjogren syndrome and sarcoidosis
Guillain-Barre syndrome
etc.
How many MS patients have cognitive impairment?
40-65% of patients with MS have cog impairment
What are the cognitive domains mostly affected by MS?
Processing speed, sustained and complex attention, executive functions including word list generation, and explicit/declarative memory (episodic). These usually progress or worsen over time.
What predicts cognitive change in MS, neuroanatomically?
Whole brain atrophy with thalamic atrophy specifically implicated accounts for significant variance in predicting cognitive dysfunction in adults with MS. Thinning of the corpus callosum has also been associated with decreased processing speed in MS.
What are considerations for patients with MS?
1) Driving. Patients may not be able to drive anymore due to slowed processing speed, reaction time, and visual scanning issues.
2) Work. Some patients may cease working (or work fewer hours) due to physical demands of work or due to effects of fatigue.
3) Mood. Depression is common. Some stimulant medications are effective for attention problems in MS and fatigue (e.g., provigil).
