ABSTRACT
Each year in the United States there are 10,000 new spinal cord injuries, which occur most frequently in teenaged persons and young adults, and add to the nearly quarter of a million cases. Due to recent advances in medical care, spinal cord injured persons now have a greatly enhanced life expectancy. The most common injury site is the 5th cervical (C5) level (15.7%) followed by C4 (12.7%), C6 (12.6%), T12 (7.6%), C7 (6.3%), and L1 (4.8%). Detailed pathological studies of human cervical spinal cord injury have revealed that lesions are of four types: contusion evolving to cavity, massive compression, solid cord syndrome, and laceration (Bunge et al., 1997). Every type of lesion involves axotomy; in most cases, the neuronal somata and target neurons of these axons remain viable. Bunge and colleagues (1997) found that in 35% of 46 cases studied there was complete anatomical discontinuity across the cord.
