Peripheral neuropathy Flashcards
What are the main features of length dependent axonal neuropathy?
Numbness starts in toes/feet and works its way up the legs.
Symmetrical and slowly progressive.
What are causes of length dependent axonal neuropathy?
Diabetes Alcohol Folate/B12/thiamine deficiency Izoniazid, cisplatin, amiodarone Pareneoplastic and neoplastic causes
What is Guillian Barre syndrome?
An acute demyelinating inflammatory polyneuropathy.
What can induce GB syndrome?
Post infection e.g. campylobacter, CMV, EBV
What is the pathophys of GB syndrome?
Post infection, the immune system thinks myelin is a bit of virus and begins attacking it.
What are the main features in GB syndrome?
A progressive ascending weakness over days with flaccis quadraparesis and areflexia.
Can have respiratory, bulbar and autonomic involvement, which can be life-threatening and cause breathing difficulties.
How is GB treated?
Intravenous immunoglobulin or apheresis
How is chronic inflammatory demyelinating polyneuropathy treated?
Steroids and immunoglobulin
How is peripheral neuropathy tested for?
Nerve conduction studies
- Myelin damage shows delayed temporal dispersion of impulses e.g. GB
- Axonal damage shows reduced amplitude.
Also, CSF shows increased protein.
What is myasthenia gravis?
An autoimmune disorder mediated by antibodies against acetylcholine receptors at the post-synaptic NMJ.
Can be associated with tumour of residual thymus.
How does myasthenia gravis present?
Fatigue of ocular, bulbar, neck, respiratory, and limb muscles (in that order).
How is myasthenia gravis tested for?
Look for anti-AchR antibodies.
EMG/nerve conduction shows decreasing muscle response to repeated stimulation.
How is myasthenia gravis treated?
Pyridostigmine - anti-acetylcholinesterase to increase Ach levels.
Immunosuppression e.g. prednisolone
