Multiple Sclerosis

Question 1

Which of the following statements regarding myelin is NOT correct?
a. Myelin enhances/speeds the conduction of nerve impulses.
b. Myelin surrounds dendrites in the central nervous system.
c. Myelin is a lipid-rich membrane ensheathing nerves.
d. Myelin provides insulation from nerve impulses.

Answer 1

Answer: b
Myelin surrounds Oligodendrocytes (CNS) and Schwann cells (PNS).
Myelin wraps around axons, NOT dendrites.

Question 2

MS is a demyelinating condition. Which one of the following statements regarding demyelination is NOT correct?
a. Demyelination may be the result of a pathological process that damages oligodendrocytes.
b. Non-ionising radiation of the brain may cause demyelination.
c. Demyelination may be the result of a pathological process that damages myelin itself.
d. MS and other demyelinating condition may be the result of auto-immunity.

Answer 2

Answer: b
Neither non-ionising radiation nor ionising radiation causes demyelination.

• “Pathological process destroys myelin and or the myelin producing cells” (slide 9) Oligodendrocytes produce and maintain myelin. (a)(c)

Question 3

Which one of the following statements regarding immune-mediated demyelination is NOT correct?
a. Cytokines are involved in the process.
b. Exogenous anti-oxidants are involved in the process.
c. T-cells are involved in the process.
d. Macrophages are involved in the process.

Answer 3

Answer: b
Presence of inflammatory cells = CD4, CD3, T cells, and Macrophages.
+ Cytokines are inflammatory signalling molecules released by immune cells that contribute to myelin damage.

Question 4

Which one of the following statements regarding clinical presentation (MS) is NOT correct?
a. There may be sensory problems.
b. There may be motor deficits.
c. Cognitive deficits appear very early in the disease process.
d. There may be evidence of cerebellar dysfunction.

Answer 4

Answer: c
Cognitive deficits appear LATER in the disease process.

• Cerebellar dysfunction = Dysarthria and ataxia
• Motor deficits = Weakness

Question 5

Which one of the following symptoms would one NOT expect to find as a manifestation of MS?
a. Bladder incontinence
b. Diplopia
c. Myopia
d. Bowel incontinence

Answer 5

Answer: c
Visual impairment = Diplopia, optic neuritis, and visual loss (blurred vision)
NOT myopia