CERTIFIED MULTIPLE SCLEROSIS
SPECIALIST EXAM PREP (CMSC)
WITH COMPLETE SOLUTIONS
Pathophysiology: Immune Dysfunction - CORRECT ANSWERSAn impairment of
immune tolerance to central nervous system tissue that ultimately leads to plaque
formation
The most widely believed hypothesis is that it is a virus-induced immune-mediated
disease.
Unusually high reactivity of immune system T cells to proteins of myelin in the CNS
,Overrepresentation of cells that enhance immune responses (pro-inflammatory T helper
cells)
Presence of immune system cells in MS lesions in the brain, spinal cord, and optic
nerves
B lymphocytes responsible for producing antibodies
Pathophysiology:
Destruction of Myelin and Axonal Damage or Loss - CORRECT ANSWERSPathology of
MS consists of lesions disseminated in location and of varying age.
Lesions are present in both white and gray matter, gray matter lesions are less evident.
Oligodendrocytes are damaged in this process.
Lesions range from acute plaques with active inflammatory infiltrates to chronic,
inactive, demyelinated scars.
Slowed conduction and conduction failure occur in demyelinated fibers. Conduction
failure is due to fiber fatigue or to an increase in body temperature.
Ongoing inflammation, demyelination, and scarring ultimately result in irreversible
axonal damage and loss.
Acute MS lesions are characterized by T lymphocytes, plasma cells, macrophages, and
bare, demyelinated, or transected axons.
Brain atrophy in MS represents a negative pathologic change.
Theories of Etiology: Genetics - CORRECT ANSWERSIncreased susceptibility is
present in families in which MS already occurs
High genetic susceptibility observed in monozygotic twins (20%-40%)
Some genetically isolated groups never develop MS (Hutterites in Canada, East-
European Gypsies)
Racial differences in MS are likely genetically based
Theories of Etiology: Environmental - CORRECT ANSWERS
Theories of Etiology: Other - CORRECT ANSWERS
Epidemiology: Geographic Distribution - CORRECT ANSWERSHigh Risk (> 30 per
100,000): northern and central Europe, Italy, northern United States, Canada,
southestern Australia, New Zealand, parts of former Soviet Union
Medium Risk (5-29 per 100,000): southern Europe, southern United States, northern
Australia, northernmost Scandinavia, much of the north Mediterranean basin, parts of
former Soviet Union, white South Africa, central South America
, Low Risk (< 5 per 100,000): Africa, Asia, the Caribbean, Mexico, northern South
America
In the US states south of the 37th parallel have a lower risk than those north of the
parallel
People who reside in temperate climates in economically developed western countries
tend to have higher rate of MS
Those older than 15 who migrate retain the MS risk of their birthplace. Those migrating
before age 15 aquire the lower risk of the new residence
Epidemiology: Gender - CORRECT ANSWERSFemales have 3>1 greater risk of
developing MS (70-75%)
PPMS = 50/50
Epidemiology: Age of Onset - CORRECT ANSWERS10-59 years, highest incidence
between 20-40 years
Average age of onset is 28-30 years
Epidemiology: Ethnicity - CORRECT ANSWERSHighest prevalence: White/Caucasian
Lowest prevalence: Japanese
Asians are more likely to have spinal cordoptic nerve disease (older age onset, fewer
brain lesions, more enhancing lesions in spinal cord)
Diagnosis of Multiple Sclerosis:
Diagnostic Criteria - CORRECT ANSWERSMS is a clinical diagnosis because no
definitive laboratory test exists.
Diagnosis of MS is based upon two episodes of neurologic symptoms referable to the
CNS separated in space (different location in the CNS), and time (different point in time
for each event).
The revised McDonald criteria for dissemination in time are detection of Gd
enhancement at least 3 months after the onset of the first clinical event or detection of a
new T2 lesion appearing at any time compared with a reference scan done at least 30
days after the onset of the initial clinical event.
Revised McDonald criteria:
1. Two attacks of disease separated in space and time
2. Must be no better explanation
3. Three possible outcomes: Multiple Sclerosis, Possible MS, Not MS
4. Monosymptomatic presentation: One attack, One objective clinical lesion, MRI
evidence
SPECIALIST EXAM PREP (CMSC)
WITH COMPLETE SOLUTIONS
Pathophysiology: Immune Dysfunction - CORRECT ANSWERSAn impairment of
immune tolerance to central nervous system tissue that ultimately leads to plaque
formation
The most widely believed hypothesis is that it is a virus-induced immune-mediated
disease.
Unusually high reactivity of immune system T cells to proteins of myelin in the CNS
,Overrepresentation of cells that enhance immune responses (pro-inflammatory T helper
cells)
Presence of immune system cells in MS lesions in the brain, spinal cord, and optic
nerves
B lymphocytes responsible for producing antibodies
Pathophysiology:
Destruction of Myelin and Axonal Damage or Loss - CORRECT ANSWERSPathology of
MS consists of lesions disseminated in location and of varying age.
Lesions are present in both white and gray matter, gray matter lesions are less evident.
Oligodendrocytes are damaged in this process.
Lesions range from acute plaques with active inflammatory infiltrates to chronic,
inactive, demyelinated scars.
Slowed conduction and conduction failure occur in demyelinated fibers. Conduction
failure is due to fiber fatigue or to an increase in body temperature.
Ongoing inflammation, demyelination, and scarring ultimately result in irreversible
axonal damage and loss.
Acute MS lesions are characterized by T lymphocytes, plasma cells, macrophages, and
bare, demyelinated, or transected axons.
Brain atrophy in MS represents a negative pathologic change.
Theories of Etiology: Genetics - CORRECT ANSWERSIncreased susceptibility is
present in families in which MS already occurs
High genetic susceptibility observed in monozygotic twins (20%-40%)
Some genetically isolated groups never develop MS (Hutterites in Canada, East-
European Gypsies)
Racial differences in MS are likely genetically based
Theories of Etiology: Environmental - CORRECT ANSWERS
Theories of Etiology: Other - CORRECT ANSWERS
Epidemiology: Geographic Distribution - CORRECT ANSWERSHigh Risk (> 30 per
100,000): northern and central Europe, Italy, northern United States, Canada,
southestern Australia, New Zealand, parts of former Soviet Union
Medium Risk (5-29 per 100,000): southern Europe, southern United States, northern
Australia, northernmost Scandinavia, much of the north Mediterranean basin, parts of
former Soviet Union, white South Africa, central South America
, Low Risk (< 5 per 100,000): Africa, Asia, the Caribbean, Mexico, northern South
America
In the US states south of the 37th parallel have a lower risk than those north of the
parallel
People who reside in temperate climates in economically developed western countries
tend to have higher rate of MS
Those older than 15 who migrate retain the MS risk of their birthplace. Those migrating
before age 15 aquire the lower risk of the new residence
Epidemiology: Gender - CORRECT ANSWERSFemales have 3>1 greater risk of
developing MS (70-75%)
PPMS = 50/50
Epidemiology: Age of Onset - CORRECT ANSWERS10-59 years, highest incidence
between 20-40 years
Average age of onset is 28-30 years
Epidemiology: Ethnicity - CORRECT ANSWERSHighest prevalence: White/Caucasian
Lowest prevalence: Japanese
Asians are more likely to have spinal cordoptic nerve disease (older age onset, fewer
brain lesions, more enhancing lesions in spinal cord)
Diagnosis of Multiple Sclerosis:
Diagnostic Criteria - CORRECT ANSWERSMS is a clinical diagnosis because no
definitive laboratory test exists.
Diagnosis of MS is based upon two episodes of neurologic symptoms referable to the
CNS separated in space (different location in the CNS), and time (different point in time
for each event).
The revised McDonald criteria for dissemination in time are detection of Gd
enhancement at least 3 months after the onset of the first clinical event or detection of a
new T2 lesion appearing at any time compared with a reference scan done at least 30
days after the onset of the initial clinical event.
Revised McDonald criteria:
1. Two attacks of disease separated in space and time
2. Must be no better explanation
3. Three possible outcomes: Multiple Sclerosis, Possible MS, Not MS
4. Monosymptomatic presentation: One attack, One objective clinical lesion, MRI
evidence
