Morphometric studies of sural nerve in childhood

Abstract

Sural nerve myelinated fiber density and myelinated fiber diameter distribution have been examined in 27 control subjects, ranging in age from 1 day to 59 years. Total transverse fascicular area was measured in 10 of the subjects. There is an exponential decline in myelinated fiber density from birth to adult life. The predicted normal density (D) at any age may be derived from the formula D = (1 × 10³)/(0.0699 + 0.00725 √t). The distribution of myelinated fiber diameters is unimodal in the first 4 months of life, and there is a denfinite bimodal distribution by 2 years of age. Total transverse fascicular area of sural nerve increases progressively from values of about 0.25 mm² in the first week to about 0.82 mm² at 9 years. Control values for sural nerve morphometry in childhood are essential for accurate interpretation of biopsies in patients with peripheral neuropathy.