How is Small Fiber Neuropathy diagnosed?
The diagnosis of small fiber neuropathy can be made with certainty, by demonstrating a reduction in the density of small nerve fibers in the skin. EMG and nerve conduction studies are usually normal in this condition, as they mostly measure the large nerve fibers in the motor or sensory nerves. The epidermal nerve fiber density is normal in patients with central nervous system disease. A skin specimen is obtained for analysis, using a 3 mm punch biopsy. The small nerve fibers in the epidermis are visualized by immunocytochemistry, using an antibody to an axonal protein. The number and structural integrity of the small fibers is then evaluated by a pathologist. Patients with small fiber neuropathy exhibit a reduction is the epidermal nerve fiber density, or structural abnormalities that are indicative of neuropathy. All procedures are done according to international standards and guidelines . Skin specimens are routinely obtained by punch biopsy at the calf and thigh, under local anaest
