Guillain-Barre & ALS & MADCOW Flashcards
- Also known as acute inflammatory demyelinating polyradiculoneuropathy
- An autoimmune disorder affecting the PNS
- Most common acute peripheral neuropathy
- Most common cause of flaccid paralysis
Guillain-Barré Syndrome (GBS)
Highest incidence of Guillain-Barré Syndrome (GBS) in young adults & the elderly
Occurs in
Men than women
Common preceding infections of Guillain-Barré Syndrome (GBS)
- Campylobacter jejuni
- CMV
Mycoplasma pneumoniae - HIV
- EBV
- influenza
Pathogenesis of Guillain-Barré Syndrome (GBS)
There is an autoimmune attack on myelin of the peripheral sensory & motor nerves
predominantly mediated by ____; cytoplasmic processes of macrophages penetrate the basement membrane of ___ & extend between the myelin lamellae; ___ is stripped away from the axon
- lymphocytes or macrophages
- Schwann cells
- myelin sheath
Clinical Presentation
of Guillain-Barré Syndrome (GBS)
= Rapidly progressive ascending motor weakness
- ___ ascending weakness
- begins distally in the ___, migrating towards the ___
- danger of respiratory muscle paralysis & death
= Depressed or absent deep tendon reflexes in the ___
= “glove & ___” paresthesia/anesthesia
Autonomic dysfunction can be seen in severe cases
- symmetric
- hands & feet
- trunk
- arms & legs
- stocking
Suspect GBS if a patient presents with:
- Rapid onset of muscle paralysis
- Areflexia
- Absence of fever
- GI or respiratory tract infection in the past 30 days
Diagnosis
of GBS
- Lumbar puncture
- Electromyography (EMG) or nerve conduction study (NCS)
- increased protein concentration with (or without) increased glucose & cell count
- albumino-cytologic dissociation
Lumbar puncture
Prolonged distal latencies & conduction slowing
EMG or NCS
to filter WBC (antibodies) out of the blood system
Plasmapheresis
to neutralize antibodies
IV immunoglobulin (IVIG)
Treatment in severe respiratory muscle weakness in GBS
Mechanical ventilation
Fatality of GBS in 5% to 10% of cases is due to
respiratory paralysis
Is often called Lou Gehrig’s disease after Lou Gehrig, a hall-of-fame baseball player for the New York Yankees who was diagnosed with ALS in the 1930s.
Amyotrophic Lateral Sclerosis
(ALS)
ALS affects nerve cells of brain and spinal cord, mostly __and ___ that needed voluntary muscle activity.
upper and lower “motor neurons”
90-95%:
5-10%:
Etiology:
Free radicals
- Mutated or misfolded ____
Higher levels of ____ which is toxic to some nerve cells.
- sporadic
- hereditary
- Superoxide Dismutase 1 (SOD)
- glutamate
SIGNS AND SYMPTOMS OF ALS:
Upper motor neuron signs
- Increased spasticity
- Babinski’s sign
SIGNS AND SYMPTOMS OF ALS:
Lower motor neuron signs
- Increasing muscle weakness (atrophy)
- Paralysis of respiratory muscles
Other Ssx of ALS
- Pseudobulbar affect – involuntary laughing and crying
- No sensory changes
- Preservation of bowel and bladder function.
Demographics of ALS:
AGE:
GENDER:
- 40-60 y.o
- ## men >women
ALS is diagnose by
- electromyography,
- nerve conduction studies and
- muscle biopsy.
ALS has NO cure.
Supportive and symptomatic treatment ___ (glutamate antagonist) - aimed at symptomatic relief.
Riluzole
aka Bovine Spongiform Encephalopathy (BSE)
a transmissible spongiform encephalopathy (TSE) that affects cattle
Madcow disease
Madcow disease is caused by
prions
Prions are derived from ___, is a disease-causing form of a normal protein called cellular prion protein (PrPC)
located on the surface of CNS cells and in other tissues of the body in mammals.
proteinacious infectious particle
Prions have no nucliec acid so it is resistant to nucleic acid breakdown procedures and recplicate by ___ to refold into a form called PrP scrapie (PrPSc) – named afterscrapie, the first TSE discovered. NO immune response.
stimulating PrPC
Prions disrupt the normal cell process of ___ which causes a buildup of faulty proteins. Accumulations in the form of plaques, or flat areas causes degeneration of brain tissue and eventually neuronal cell death
protein recycling
The destruction of neural cells causes tiny holes in the brain tissue and a sponge-like appearance under the microscope, thus giving rise to the term
spongiform disease
early and prominent theory was that BSE is derived from
scrapie
TRANSMISSION to CATTLE
of BSE
feeding ruminant-derived MBM (meat bone meal) to cattle as a protein supplement was the mechanism by which BSE was transmitted among cattle
Pathogenesis of BSE
- Ingestion of pathogenic prion infected material
- GIT-lymphoid system
- ANS
- CNS
Diagnosis of BSE
- Elisa
- Western Blot/Immunoblot
