3(E): Peripheral Polyneuropathies Flashcards
What is a peripheral neuropathy
Damage to multiple peripheral nerves
Give 3 features of neuropathies (compared to myopathies)
- Distal muscles affected first
- Early muscle waisting
- Diminished or absent reflexes
What genetic condition can cause poly neuropathies
Charcot marie tooth
What are acquired causes of polyneuropathy
Inflammatory: Gullian Barre, Chronic Demyelinating Polyneuropathy
Toxin: Alcohol, Lead
What toxins can cause polyneuropathy
Alcohol, Lead
What causes alcoholic neuropathy
Direct toxin effect of alcohol
Vitamin B12 deficiency
How does alcoholic neuropathy present
Loss sensation prior to motor symptoms
What does vitamin B12 deficiency cause
Subacute combined degeneration spinal cord
What tract is impacted first in subacute combined degeneration spinal cord
DCP
How does diabetic neuropathy present
Loss of sensation in glove and stocking distribution. Burning in the feet worse at night
What is the inheritance pattern of Charcot Marie Tooth
Autosomal dominant
What is predominantly lost in Charcot Marie Tooth
Motor symptoms
What are 3 distinct features of CMT
Pes cavus = high arch foot
Hammer toes
Stork legs = atrophy calf muscles
What is a common presenting story for CMT
Recurrent sprained ankles
What is ordered for CMT
NCS
Nerve Biopsy
What is seen on NCS in CMT
reduced conduction velocity
What is seen on nerve biopsy in CMT
myelination and then demyelination = onion peel appearance
What is Gullian Barre Syndrome
Immune-mediated demyelinating peripheral polyneuropathy
What do patients experience before neuronal symptoms in GBS
URTI or GI Infection 1-4W prior
What pathogens cause GBS
- Campylobacter Jejuni
- CMV
- EBV
Explain symptoms of Gillian barre
Progressive weakness in all four limbs to cause paralysis. It is an ascending paralysis - meaning it starts in the legs and progresses to the arms. Proximal muscles are affected first.
Areflexia
Autonomic Dysfunction - arrhythmia, gastroparesis and voting dysfunction
Describe reflexes in Gullian Barre
Areflexia
What autonomic dysfunction may occur in gullian barre
- Arrhythmia
- Gastroparesis
- Voiding dysfunction
What is a late sign of Guillian barre
Sensory Loss
Landry Paralysis
What is Landry paralysis
Involvement of respiratory muscles - medical emergency
What is a variant of GBS
Miller-Fisher
What is Miller-Fisher Syndrome
Ophthalmoplegia and ataxia
What muscles are affected first in Miller-Fisher
Extra-occular muscles
Describe muscle involvement in Miller-Fisher
In contrast to GBS, it is a descending paralysis. Affects arms before legs. Usually starts with eye muscles
What antibodies are present in Miller-Fisher
anti-GQ1b antibodies
What investigations are ordered in Gillian barre
- NCS
- EMG
- Vital Capacity monitoring
(anti-GQ1b - for miller fisher)
What phenomenon is seen on CSF in Gullian Barre
Albumincytologic dissociation
What is albuminocytologic dissociation in Gullian Barre
- Raised albumin
- Normal WCC
Explain conduction velocity in GBS
Decreased
What needs to be monitored in GBS
Vital Capacity
How is GBS managed
IVIg
What is ineffective in GBS
Glucocorticoids
What is complication of GBS
Respiratory Failure
