PBL 3 - MS

Question 1

MS risk factors (3)

Answer 1

Smoking
Low intrauterine vitamin D
Viral infection e.g. EPV, JC virus

Question 2

Vitamin D levels regulate …

Answer 2

immune response by decreasing production of proinflam cytokines

Question 3

Plaques =

Usually …, asymmetrical / asymmetrical and localise in the ….

Answer 3

Sclerosis of astrocytes

Usually multiple, symmetrical and localise in periventricular white matter

Question 4

Chromosome encodes MHC

Answer 4

6

Question 5

Pathology (4)

Answer 5

TH1 CD8 cells cross BBB as BBB damaged
T cells attack MAG, MOG, MBP proteins on oligodendrocytes
Get demyelination and inflammation = neuronal destruction
Lymphocytes destroy oligodendrocytes release glutamate - excitotoxicity

Question 6

Remission caused by:

Answer 6

Na channel redistribution and attempts by CNS to remylinate axons

Question 7

BBB made up of (2)

Answer 7

Astrocytes end feet - wall

Pericytes - contractile cells wrap around endothelial cells - form tight junctions broken in MS by Th1

Question 8

MS symptoms: (6)

Answer 8

• motor
• sensory
• brain stem
• optic neuritis - super myelinated, DDX: neuromyleitis optica
• bladder and bowel inconvenience
• fatigue

Question 9

Uthoffs pheonmeom:

Answer 9

• exacerbation of symptoms if the body temp increases, this further impairs conduction by demyelination nerves

Question 10

Progressive multifocal leukoencelopathy: (4)

Answer 10

Caused JC virus in immunosuppressive
Fatal
Progressive damage and inflammation = brain white matter in multiple locations (like MS but progresses faster)

Question 11

Intranucleu opthalmoplegia -

Answer 11

Impairment of adduction
Disorder of MLF - connects pontine RF to abducens nucleus pm contralateral side and to CN III nucleus on ipsilateral side
Bilateral INO - MS
Unilateral INO - stroke