What are the indications for sural nerve biopsy?
Sural nerve biopsy is most helpful when the underlying condition is multifocal and asymmetric—mainly when a vasculitic etiology is suspected.
It may be obtained in chronic demyelinating neuropathies with the aim of confirming the diagnosis when the clinical and electrophysiologic findings have been inconclusive, especially in patients who may be candidates for therapies with potentially harmful side effects.
With the advent of genetic and other testing modalities, nerve biopsy is less necessary but may be of value as a final resort in patients with progressive, disabling peripheral neuropathy of undetermined etiology.
The yield of nerve biopsy when vasculitis is suspected ranges from 50% to 60% while the yield in unknown neuropathy is in the 15% to 25% range.