Survival of spinal motoneurons after various types of brachial plexus root injuries: an experimental study

Abstract

Objective To investigation survival of spinal motoneurons after brachial plexus root rupture or avulsion injury. Methods 72 adult healthy SD rats were randomly divided into two groups, root rupture and root avulsion. Spinal cord sample was harvested at 9 different postoperative intervals, with 4 rats each. Another 4 rats served as control. The number of the motoneurons in the cervical spinal cord anterior horn was calculated.Results There was no significant change in the number of spinal motoneurons in the root rupture group. In the root avulsion group, the number of spinal motoneurons began to decrease 1 week postoperatively, and was 30 % and 70 % less than that of the control group 2 weeks and 6 weeks after the operation respectively. Compared to that in root rupture group, significant difference was seen at different intervals in root avulsion group 1 week after the operation.Conclusions Root rupture of the brachial plexus did not cause remarkable change of the spinal motoneurons. Root avulsion, however, resulted in death of spinal motoneurons with rapid speed and severe extent.