What is the peak onset for Multiple Sclerosis (MS)?
Between 20 and 30 years of age
Who is more likely get MS?
Women (1.4-3.1 times more likely than men)
Where is the incidence of MS the highest?
In the northern most latitiudes of northern and southern hemispheres
T/F an individual that migrates at the age of 15 to another area will take on the risk profile for that area
False; they must have migrated before the age of 15
Where are epidemics of MS noted and what is thought to be the cause?
The Faroe islands, shetland and Orkney Islands, Iceland, and Sardinia after british occupation in WWII
What populations appear resistant to MS?
Hutterites and Native Americans (North American), Lapps (Scandanavia)
How high is the incidence in first generation relatives?
20x than in general population
What is the concordance rate between monozygotic twins? Dizygotic twins?
30%; <5%
What is the etiology?
Unknown; autoimmune reaction to oligodendrocytes and myelin (viral connection in genetically predisposed)
Where do plaques most frequently occur?
T/F edge of plaque forms an abrupt interface with normally myelinated white matter
True
T/F plaque does not impinge on anything else
False. Impinges on gray matter
What is typical within plaque
Axon sparing (axon is not destroyed)
What is the mechanism of plaque evolution?
Unclear. Unknown if demyelination precedes or is secondary to inflammation
What is the current plaque evolution theory?
Acute inflammatory response to T cells, plasma, and macrophages results in demyleination by:
What are ultrastructural characteristics of plaques?
What is the possibility of remyelination?
Earlier in the disease there are more oligodendrocytes preserved in plaque thus remyelination is more likely. Chances decrease as the disease progresses
What are the results of demyelination?
What is nerve fiber fatigue?
feeling of fatigue due to the increased energy demand to conduct a nerve impulse
What type of diagnosis is MS?
Diagnosis of exclusion (must do testing to exclude other causes)
What criteria is included in the diagnosis?
Characteristics of definite MS:
Characteristics of probable MS:
Characteristics of possible MS: