Endoneurial edema in sural nerve may indicate recent onset inflammatory neuropathy

Abstract

Introduction: Sural nerve biopsy is an important means of establishing the diagnosis of inflammatory neuropathies. We investigated the diagnostic value of endoneurial edema. Methods: Diagnostic sural nerve biopsies from 42 patients with inflammatory and 28 patients with noninflammatory neuropathies were re-evaluated for the presence of endoneurial edema. Edema was assessed on hematoxylin-eosin stained paraffin and frozen sections and on azure II-methylene blue stained semithin sections. We determined the area of endoneurial edema on digitized images in relation to the entire endoneurial area of each fascicle. Results: Edema was more extensive in neuropathies with short disease duration (≤12 months) as compared to long duration (>12 months; P < 0.01). Edema in inflammatory neuropathies of ≤12 months duration covered a larger area than in noninflammatory neuropathies (P < 0.01), and the extent of edema correlated negatively with disease duration (P < 0.05). Conclusions: Endoneurial edema may be a useful additional disease marker in inflammatory neuropathies of recent onset. Muscle Nerve 53: 705–710, 2016