Fig. 6. Transverse sections obtained from 10 mm caudal to the conus 4 days after a 1-h intrathecal infusion of saline (  A ) and 2.5% levobupivacaine (  B ).  Arrows indicate damaged fascicles in cauda equina. Histologic changes in cauda equina were characterized by edema and axonal degeneration, including appearance of myelin ovoid, and swelling, atrophy, and loss of axons with macrophage infiltration.