Idiopathic ~ 50%
Congenital
HMSN
Friedrich's Ataxia
Acquired
Trauma
Infection
- Leprosy
- TB
- Syphilis
Tumour
- Malignancy
- Myeloma
- Polycythemia rubra vera
Inflammatory
- GBS
- SLE
- RA
- Sarcoid
- PAN
Metabolic
- DM
- CRF
- Chronic liver disease
- Amyloid
- B1 / B6 / B12
- Thiamine
Endocrine
- hypothyroid
Drugs and Toxins
- Alcohol
- Lead
- Phenytoin
- Metronidazole
- Nitrofurantoin
- Vincristine