Multiple Sclerosis

Question 1

What is MS?

Answer 1

an autoimmune disorder characterised by the demyelination of neurons in the brain, spinal cord and cranial nerves leading to impaired nerve transmission

Question 2

Environmental risk factors for MS

Answer 2

Epstein-Barr Virus: herpes

Low Vitamin D (less sunlight = higher MS risk)

Question 3

Genetic risk factors for MS

Answer 3

HLA-DR2 gene association

More common in females

Question 4

Pathophysiology of MS: Autoimmune activation

Answer 4

T cells cross the blood brain barrier

they recognise myelin as foreign cells (autoantigen)

T cells release cytokines = inflammation

Question 5

Pathophysiology of MS: Inflammatory cascade

Answer 5

increased adhesion molecules for WBC recruitment

Vasodilation and increased vascular permeability

macrophages and other immune cells infiltrate and attack myelin sheath

Question 6

Pathophysiology of MS: Demyelination

Answer 6

destruction of oligodendrocytes (cells that produce the myelin sheath)

Loss of myelin sheath = voltage leaks out of axons

Impaired saltatory conduction = slower or blocked nerve impulses

Question 7

Pathophysiology of MS: Plaque formation

Answer 7

large, localised areas of inflammation and demyelination called plaques

Question 8

Pathophysiology of MS: Remission phases

Answer 8

inflammation can subside temporarily

Partial remyelination or compensation by unaffected neurons = transient recovery of function

Question 9

Relapsing-Remitting MS

Answer 9

Episodes of new or worsening symptoms followed by partial or full recovery

Question 10

Secondary Progressive MS

Answer 10

Initially relapsing-remitting, later becomes steadily progressive

Question 11

Primary Progressive MS

Answer 11

Gradual worsening from onset, without relapses

Question 12

Progressive-relapsing MS

Answer 12

Steady progression with superimposed relapses

Question 13

Signs & Symptoms of MS

Answer 13

Fatigue
Vision Problems
Numbness
Tingling
Muscle spasms
Mobility Problems
Pain
Problems with thinking and planning
Depression and anxiety
Bladder problems
Bowel problems
Speech and swallowing problems

Question 14

Cranial Nerve involvement with MS (optic nerve)

Answer 14

Optic nerve contains oligodendrocytes = susceptible to demyelination

Symptoms = decreased visual acuity, colour vision deficits, relative afferent pupillary defect

Question 15

Cranial Nerve involvement with MS (Oculomotor, Trochlear and Abducens)

Answer 15

Demyelination = abnormal ocular movements

Symptoms = nystagmus, strabismus and diplopia