Demyelinating pathologies - Multiple sclerosis and Guillian Barr Syndrome Flashcards
What is multiple sclerosis
A demylination disorder caused by autoimmune- cell mediated Type 4 hypersensitivity
RF For MS
**WOMEN 20-40 years old
**EBV infection
VIT D Deficency
HLA DR2
other AI
What are the different patterns of MS
relapsing remitting
Type 1 - Progressive decline
Type 2 - Relapsing remitting then type 1
How does autoimmune hypersensitivity lead to MS?
CEll mediated hypersensitvity (T4) - macrophages and t cells against myelin basic protein of oligodendrocytes (CNS myelinating cells)
= Demylination of CNS neurones
= Slows or blocks transmission to and from the brain
How would MS present?
MC -
Optic nueritis (blurred vision, red desaturation - cant see red)
Numbness, parathesia tingling and other strange sensations
Uhtoff’s phenomenon (Sx worse w/ heat / Bath)
Weakness
Bowel/Bladder dysfunction
Signs:
Charcots neuological triad:
Intention tremor + dysarthia (speech) + nystagmus (involuntary eye movemnts)
Cerebellar signs: Imbalance / incoordination - wide based gait
UMN signs: muscle weakness, spasms, tight muscles, clonus
Lhermitte’s phenomenon: electric shock sensation on neck flexion
also eye shit
What si the diagnostic criteria used for MS?
MCDONALD’s Criteria
How to investigate MS?
GS - MRI brain and spine
Demylinating plaques (dawson’s fingers)
Dissemenation of old and new lesions
Other: Lumbar puncture - Increased oligoclonal IgG (not seen in blood)
Treating MS?
Relapse / Acutely:
Oral/IV methylprednisolone
2nd line: Plasma exchange
Maintenance:
B inteferon (reduces relapse but not progression
or glatiramer
mAb - Alemtuzumab (anti-CD52) and Natalizumab (anti-α4𝛃1-integrin)
Fingolimod: contains wcc in lymphs
Multiple sclerosis ddx
Gullian barr Syndrome
What is guillian barr syndrome?
A demyelinating response post infection (URTI, gastroenterititis) against peripheral mylinating gangliosides (T2 hypersensitivities)
HIGHLY ASSOCIATED WITH campylobacter jejuni
What causes gullian barr syndrome?
TYPE 2 Hypersensitivity
Theoriesed to be molecular mimicry’
A pathogenic antigen (e.g. Campylobacter jejuni, CMV, EBV)) resembles myelin schwann cells in the peripheral nervous system
The immune system targets the antigen and attacks the myelin sheath of sensory and motor nerves
This autoimmune process involves the production of anti-ganglioside antibodies (anti-GMI is positive in 25% of patients)
How would guillian abrrr syndrome present?
Progression is subacute and typically peaks 2-3 weeks after disease onset
Typically males w/ Bimodal young/old
iMPORTANT TO KNOW
Tingling and numbness then muscle weakness(lower>upper)
w/ autonomic dysfunction 50%: loss of deep tendon reflex (resp failur)
What types of guillian barr syndrome are there?
Acute inflammatory demyelinating polyneuropathy (ADIP): ~90% of cases
Acute motor axonal neuropathy (AMAN)
Acute motor and sensory axonal neuropathy (AMSAN)
Miller-Fisher Syndrome (MFS):
Classic triad: ataxia, areflexia, and ophthalmoplegia
Eye muscles are typically affected first
Usually causes descending (rather than ascending) paralysis and anti-Gq1b antibodies are present in 90% of cases [3][5]
Investigating GBS
Bloods:
exclude: electroylate abnomalitleis/folate def/b12def/hypothyroidism/severe hepatic disease
Stool or sputum culture - features of infection
Spirometer
Serology: Anti-gla
Lumbar puncture: Raised Protein
Investigating GBS
Lumbar puncture: Raised proteins / Normal wcc
Nerve conduction studies - reduced conduction velocity
BRAIN/SPINE MRI
GS: Serology: Anti-GLA Ab (IgG)
Exclude other DDX:
Bloods:
exclude: electroylate abnomalitleis/folate def/b12def/hypothyroidism/severe hepatic disease
