Specific causes of peripheral neuropathy
- D –Diabetes
- A –Alcoholism
- V –Vitamin Deficiency – B12
- I –Infective / inherited – Guillian-Barrie / Charcot-Marie-Tooth
- D –Drugs – e.g. isoniazid
- Demyelination – e.g. Guillian-Barre syndrome, post-diphtheric neuropathy, hereditary sensory-motor neuropathies – usually occurs as a result of schwann cell damage.
- Axonal degeneration – usually occurs in toxic neuropathies – conduction speed remains normal, and the axon tends to dies of peripherally first, then more proximally. Surviving axons often strive to re-innervate affected areas
- Wallerian degeneration – this describes fibre degeneration when the fibre is cut or crushed. Both the axon and the myelin sheath will degenerate over several weeks after the incident.
- Compression – e.g. carpal tunnel syndrome – there is local demyelination at the site of compression. Occurs when the compression is not as severe as in wallerian degeneration.
- Infarction – e.g. polyarteritis nodosa, Churg-Strauss syndrome, diabetes – there will also be wallerian degeneration distal to the infarct.
- Infiltration – e.g. leprosy, malignancy, inflammation, sarcoidosis
- Remyelination – more likely to occur than axonal regrowth
- Axonal regrowth – this can occur at a rate of up to 1mm per day