Multiple Sclerosis (MS) study
guide updated 2026/2027 syllabus
Pathophysiology & Etiology
1. What is the primary pathophysiologic mechanism causing neurologic deficits in
multiple sclerosis?
ANSWER ✓ Demyelination of CNS neurons with axonal damage
2. Which cells are responsible for myelin production in the central nervous system and
are targeted in MS?
ANSWER ✓ Oligodendrocytes
3. What is the composition of the myelin sheath that is destroyed in MS?
ANSWER ✓ A fatty layer of lipid and protein constituents around nerve cells that
increases the speed of electrical transmission
4. Which type of hypersensitivity reaction is multiple sclerosis classified as?
ANSWER ✓ Type IV hypersensitivity reaction (T cell-mediated)
5. Which two T-helper cell subtypes promote pro-inflammatory responses and CNS
damage in MS?
ANSWER ✓ Th1 and Th17 cells
6. What cytokine cascade do Th1 and Th17 cells release that causes inflammation in the
CNS?
ANSWER ✓ TNF-α and IFN-γ
7. What viral infection has the strongest evidence for a causal relationship with the
development of MS?
ANSWER ✓ Epstein-Barr virus (EBV)
8. What is the postulated mechanism by which EBV may trigger MS?
ANSWER ✓ Latent virus infection triggers a secondary autoimmune response when
activated
9. What is the name for the scarred areas of demyelination in the CNS of MS patients?
ANSWER ✓ Plaques
, 10. What glial cell process develops in and around the plaques of MS?
ANSWER ✓ Astrogliosis
11. Where in the CNS are MS plaques most commonly found?
ANSWER ✓ Periventricular white matter, lateral and posterior columns (especially
cervical regions), and optic nerves
12. Which region of the CNS is spared from MS involvement because it is encapsulated
within the dura?
ANSWER ✓ Cranial nerves I and II (olfactory and optic nerves are actually affected; this
is a trick - CN I and II are CNS tissue and ARE affected)
13. What is the role of the blood-brain barrier (BBB) in MS pathogenesis?
ANSWER ✓ Activated T cells outside the CNS cross the BBB to initiate an immune attack
on myelin
14. What genetic markers on cell surfaces are associated with increased MS risk?
ANSWER ✓ Human leukocyte antigens (HLA)
15. How does cigarette smoking affect MS risk?
ANSWER ✓ It increases the risk of developing MS
16. Why is growing up in a temperate climate a risk factor for MS?
ANSWER ✓ Decreased sun exposure leads to lower vitamin D levels
17. What dietary factor deficiency is linked to increased MS risk?
ANSWER ✓ Vitamin D deficiency
18. What is the ratio of women to men affected by MS?
ANSWER ✓ 2-3:1 (women more commonly affected)
19. Is MS considered an autoimmune disease, a neurodegenerative disease, or both?
ANSWER ✓ Both - a chronic neuroinflammatory and neurodegenerative disease
20. How does the prevalence of MS vary between temperate and tropical climates?
ANSWER ✓ MS is more common in people living in temperate climates (1 in 2,000)
compared to tropical climates (1 in 10,000)
Clinical Patterns & Disease Course
guide updated 2026/2027 syllabus
Pathophysiology & Etiology
1. What is the primary pathophysiologic mechanism causing neurologic deficits in
multiple sclerosis?
ANSWER ✓ Demyelination of CNS neurons with axonal damage
2. Which cells are responsible for myelin production in the central nervous system and
are targeted in MS?
ANSWER ✓ Oligodendrocytes
3. What is the composition of the myelin sheath that is destroyed in MS?
ANSWER ✓ A fatty layer of lipid and protein constituents around nerve cells that
increases the speed of electrical transmission
4. Which type of hypersensitivity reaction is multiple sclerosis classified as?
ANSWER ✓ Type IV hypersensitivity reaction (T cell-mediated)
5. Which two T-helper cell subtypes promote pro-inflammatory responses and CNS
damage in MS?
ANSWER ✓ Th1 and Th17 cells
6. What cytokine cascade do Th1 and Th17 cells release that causes inflammation in the
CNS?
ANSWER ✓ TNF-α and IFN-γ
7. What viral infection has the strongest evidence for a causal relationship with the
development of MS?
ANSWER ✓ Epstein-Barr virus (EBV)
8. What is the postulated mechanism by which EBV may trigger MS?
ANSWER ✓ Latent virus infection triggers a secondary autoimmune response when
activated
9. What is the name for the scarred areas of demyelination in the CNS of MS patients?
ANSWER ✓ Plaques
, 10. What glial cell process develops in and around the plaques of MS?
ANSWER ✓ Astrogliosis
11. Where in the CNS are MS plaques most commonly found?
ANSWER ✓ Periventricular white matter, lateral and posterior columns (especially
cervical regions), and optic nerves
12. Which region of the CNS is spared from MS involvement because it is encapsulated
within the dura?
ANSWER ✓ Cranial nerves I and II (olfactory and optic nerves are actually affected; this
is a trick - CN I and II are CNS tissue and ARE affected)
13. What is the role of the blood-brain barrier (BBB) in MS pathogenesis?
ANSWER ✓ Activated T cells outside the CNS cross the BBB to initiate an immune attack
on myelin
14. What genetic markers on cell surfaces are associated with increased MS risk?
ANSWER ✓ Human leukocyte antigens (HLA)
15. How does cigarette smoking affect MS risk?
ANSWER ✓ It increases the risk of developing MS
16. Why is growing up in a temperate climate a risk factor for MS?
ANSWER ✓ Decreased sun exposure leads to lower vitamin D levels
17. What dietary factor deficiency is linked to increased MS risk?
ANSWER ✓ Vitamin D deficiency
18. What is the ratio of women to men affected by MS?
ANSWER ✓ 2-3:1 (women more commonly affected)
19. Is MS considered an autoimmune disease, a neurodegenerative disease, or both?
ANSWER ✓ Both - a chronic neuroinflammatory and neurodegenerative disease
20. How does the prevalence of MS vary between temperate and tropical climates?
ANSWER ✓ MS is more common in people living in temperate climates (1 in 2,000)
compared to tropical climates (1 in 10,000)
Clinical Patterns & Disease Course
