Diagnosis:
Appropriate clinical features plus evidence of amyloid on biopsy
Clinical features:
Small fibre neuropathy +/-autonomic failure (see under small fibre neuropathy)
Findings on investigations:
NCS/EMG:
- Normal
- Or features of carpel tunnel syndrome
Pathology, sural nerve biopsy:
Eosinophilic deposits in the endoneurium and vessel walls
Congo red: apple green birefringence
Sirius red: stains amyloid red
Axonal loss
Loss of small fibres and preservation of large fibres may be seen
Can occur in systemic AL amyloidosis