The following causes all result in axonal loss:

Idiopathic

• Age-related

Metabolic neuropathies

• Diabetes mellitus - most common cause of neuropathies in developed countries
• Uraemia
• Hepatic disease
• Thyroid disease
• Acute intermittent porphyria
• Amyloidosis
• Vitamin deficiencies
  • B12/folate
  • Copper
  • Thiamine (vitamin B1) - Wernicke–Korsakoff’s syndrome

Toxic neuropathies

• Alcohol - polyneuropathy, mainly in the lower limbs, occurs with chronic alcohol use
• Amiodarone
• Phenytoin
• Chemotherapy (cisplatin/vincristine)

Neuropathy in cancer

• Polyneuropathy is seen as a paraneoplastic syndrome
• Occurs in myeloma and other plasma cell dyscrasias

Neuropathies in systemic diseases