Nerve biopsies in patients with peripheral neuropathy: A prospective evaluation.

Background: In approximately 25% of peripheral neuropathy cases, diagnosis remains obscure. In India, leprosy continues to remain one of the most frequent causes of peripheral neuropathy. We, in this prospective evaluation, performed nerve biopsies in patients with peripheral neuropathy for early confirmation of the diagnosis. Materials and Methods: A total of 55 consecutive cases of peripheral neuropathy were included in this study. All patients were subjected to clinical and electrophysiological evaluation. Sural nerve biopsies were performed in all the patients. Result: After a nerve biopsy in 29 cases, we were able to identify the underlying cause of peripheral neuropathy. In 26 cases, the diagnosis remained obscure. The most frequent histopathological diagnosis was leprosy, which was seen in 20 cases. Other diagnoses were chronic demyelinating neuropathy (four cases), vasculitis (two cases), and amyloidosis in one case. In two biopsies, the findings were consistent with hereditary neuropathies. The demonstration of lepra bacilli was the most distinctive feature. In addition, foamy macrophages (100%) and granuloma (100%) formation, epineurial (83.3%) and endoneurial infiltration (69%) along with epineurial (87.5%) and perineurial thickening (77.3%) were also noted more frequently in leprosy-associated neuropathy. Conclusion: The nerve biopsies revealed that leprosy was the most common etiology in patients with peripheral neuropathy. In approximately 47% of the cases, even nerve biopsies failed to establish a confirmed diagnosis.