Radiculoneuropathy

Radiculoneuropathy is a degenerative disease of the spinal cord and spinal roots, with concurrent atrophy of skeletal muscle in the lumbar region and hind limbs. Lesions occur in the spinal cord and spinal nerve roots (Fig. 2.53). Lesions consist of demyelination, swollen axon sheaths, and axonal loss. These changes are restricted to white matter, and are most severe in the

FIG. 2.53. Lumbar spinal cord from an aged rat with radiculoneuropathy. Note the axon sheath swelling in nerve bundles of the cauda equina.

lateral and ventral funiculi and cauda equina. This syn­drome is common in aged laboratory and pet rats, and is manifest clinically as posterior weakness or paresis.