Nerve biopsy is typically performed in distal, noncritical sensory nerves without using imaging to target the more involved regions. The yield of these procedures rarely achieves more than 50%. In selected cases where preoperative evaluation points toward a more localized (usually a more proximal) process, targeted biopsy would likely capture the disease. Synthesis of data obtained from clinical examination, electrophysiological testing, and MRI allows biopsy of a portion of the major mixed nerves safely and efficiently.

In patients presenting with predominantly motor symptoms, some groups routinely biopsy mixed or pure motor nerves.

The diagnostic yield is difficult to assess due to diverse methodology and different spectrum of conditions selected for biopsy, but ranges from 35% to 50% for sural nerve biopsy ^{1) 2) 3)}.