Polyneuropathy part 1 - GBS Flashcards
Briefly define the term Guillain Barre Syndrome
Acute onset idiopathic, demyelinating, autoimmune/inflammatory, post-infections (collection of conditions leading to…), symmetrical ascending loss (peripheral) polyneuropathy with both motor and sensory symptoms and possible autonomic changes
List the factors that predispose to GBS
- Follows infection (both bacterial and viral)
i. Campylobacter jejuni - axonal-onset variant; affected patients commonly experience more rapid deterioration
ii. EBV
iii. Herpes
iv. Lyme disease
v. HIV
vi. Zika virus
vii. gangliosides (Grey matter lipids in brain) are targeted by immunoglobulins and share antigenic epitopes with some bacterial and viral antigens - Younger adults (20-50yrs)
- Linked to vaccines i.e. Swine flu
Describe the clinical manifestations of GBS
- Symmetrical paralysis
- respiratory
- dysarthria
- dysphagia
- bowel and bladder - Rapidly progressing
- minimal mm atrophy
- loss of deep tendon reflexes
- ascends distal to proximal (lower extremities up)
- weakness
- ataxia
- bilateral paraesthesia –> paralysis
Describe the typical clinical course of GBS
- follows recent infection acutely
- rapidly progresses
- begins in lower extremities and ascends bilaterally
- *weakness/ataxia
- *progresses up body
Discuss the diagnosis of GBS
- Exclusion of other conditions i.e. fasting blood glucose, genetic testing, test for toxins, Vit B12 etc.
- normal labs usually
- CSF show elevated protein but no cells - albumin-cytologic dissociation
- Most accurate test is EMG/nerve conduction studies
Discuss the treatment of GBS
- Pt. admitted to hospital
- observe vital capacity (diaphragmatic involvement)
- tracheostomy - plasma exchange or intravenous immunoglobulin
- physical therapy useful
- CANT use corticosteroids
Discuss the prognosis of GBS
- 80-90% full recovery within a few months
- physical therapy aids recovery
- 5% mortality
Discuss complications of GBS
- breathing difficulties
- cardiovascular complications
- severe nerve pain
- bowel/bladder retention
OTHER:
*Syndrome of inappropriate antidiuretic hormone hyper secretion (SIADH)
*Autonomic dysfunction-associated encephalopathy – vasogenic oedema –> fluid leakage = endothelial damage @ BBB –> chemo/cytokine
*reversible cerebral vasoconstriction syndrome – causes headaches - recurrence
- death
Briefly define the term Charcot-Marie-Tooth Disease (CMT)
Hereditary autosomal dominant sensorimotor polyneuropathy. Characterised by progressive distal muscle weakness and atrophy, often associated with mild to moderate sensory loss, depressed tendon reflexes and high arched feet. Caused by demyelination
Discuss the epidemiology and classification of CMT
1-7 types
i. CMT type 1 (CMT1; demyelinating form)
ii. CMT type 2 (CMT2; axonal form)
iii. CMT type 3 (Dejerine-Sottas disease) - P0 or PMP-22 gene
b. Cultural
i. 82.3/100,000 in Norway
ii. 9.7/100,000 in Serbia
c. 1/2,500 people
Discuss the aetiology of CMT
- typically onset in childhood
- familial component
- autosomal dominant - mitofusin 2 gene (affects the formation of myelin
What is the pathological process occurring in CMT?
a. Autosomal dominant spectrum related to myelin sheath
b. The mutation results in abnormal myelin that is unstable and spontaneously breaks down.
c. demyelination, leading to uniform slowing of conduction velocity in motor and sensory but not c type nerve fibres (pain/temp)
d. Schwann cells proliferate and form concentric arrays of remyelination repeatedly
In other words: The protein that codes for myelin production is mutated therefore retarding the myelin production
Discuss the clinical picture of CMT type 1
a. 1st or 2nd decade
b. Symmetrical distal LL weakness (stork legs) (some UL involvement)
c. ↓ Reflexes
d. Hypertophic nerves
e. +/- UL tremors
f. Pes Cavus
g. Hammer toes
h. Family hx
How is CMT diagnosed?
a. First symptoms
b. Family hx* (people normally know things like this run in the family)
c. NCV test (nerve conduction velocity) and EMG
i. Delayed response type 1
ii. Small responses type 2
d. Genetic testing*
