Skin nerve biopsy in the diagnosis of peripheral neuropathy

Objective To find out a reference range of epidermal nerve fiber density in normal humans and compare the concordance between clinical features, electrophysiology and the results of skin biopsy. Methods Fifty-one patients with peripheral neuropathy and 10 normal controls were studied. Skin biopsies were obtained from distal leg and/or proximal leg and nerves identified using immunohistochemistry with antibody against protein gene product (PGP) 9. 5. Forty-one in 51 performed routine nerve conduction vdocity and electromyography, 21 in 51 performed sympathetic skin response(SSR). The concordance of the consequences was compared. Results Intraepidermal nerve fiber density (IENFD) was (21.4 + 2. 7) /mm in thigh and (15.4±2. 2) /mm in the distal part of the leg in normal controls. IENFD was (15.0± 6. 3)/mm and (8. 1±5.9) /mm in patients. The intraepidermal nerve fiber density was significantly lower in the patients than in the normal controls both in proximal (t = 2. 976, P = 0.004) and distal legs (t= 3.191, P=0.002). Forty-eight out of 51 patients showed abnormalities in skin biopsy, among which 33 patients had length-dependent neuropathy. In the group of abnormal skin biopsy, 41 received routine electrophysiology, among which 21 (51.2%) were abnormal and they were performed SSR, turning out that 17 (81.0%) were abnormal. In 29 patients who had only small fiber neuropathy, 27(93. 1%) showed abnormalities in skin biopsy, out of whom 20 were performed routine electromyography, and it identified that 6 (30. 0%) were abnormaL In 14 receiving SSR, 11 were abnormal. Conclusion Skin biopsy is safe and tolerable, which has a higher sensitivity especially in small fiber neuropathy. Key words: Peripheral nervons system diseases;  Nerve fthers;  Biopsy;  Electromyography