[A histo-morphometrical composition of the lumbar spinal nerve-fiber of the aged subjects].
Changes of the components of the myelinated fibre of lumbar spinal nerves and their relationships to the corresponding intervertebral foramina were studied on fifteen autopsied subjects over 65 years of age with a histo-morphometrical technique and compared with those of 14 younger aged cases as controls. Mixed spinal nerves were obtained at the outlet of each foraminal canal, fixed in 10% formalin, and embedded in paraffin. Sections for light microscopy were cut at 2.5 micra thick and stained with luxol-fast blue. A histo-morphometrical study was performed by actual measuring on enlarged photomicrographs (x 2,000). The size-frequency histograms of the myelinated fibre showed a bimodal distribution with two peaks at 1-3 micra (small fibre) and 7-10 micra (large fibre) in control group. In senile group, it was noteworthy that the peak of the large fibre was diminished or sometimes absent with marked intraneural fibrosis and an increase in small fibre density was observed. And these changes were more prominent in cases with severe disc degeneration.
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008161:Lumbosacral Region; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure; D013127:Spinal Nerves / Q000166:cytology / Q000648:ultrastructure*