Experimental Progressive Compression Neuropathy in the Rabbit

Structural and functional alterations caused by chronic progressive constriction of nerve were studied after application of siliconized rubber tubes to the sciatic nerve of 3- to 5-week-old rabbits. These studies indicated that careful application of the tube caused no initial damage. Gradual compression by unyielding walls of the tube developed between the second and third month and progressed with growth of the animal. This was associated with increasing slowing of motor conduction across the constricted segment. In histologic examination the predominant change was segmental demyelination in the compressed and neighboring portions of the nerve. Outer fibers of the compressed segment were affected more significantly than those centrally located. Biomechanical and ischemic factors may be responsible for these changes. Proximal and distal segments showed no important reduction in caliber or changes in internodal distance.