title: Anterior cornual motoneuron regression pattern after sacral plexus avulsion in rats.
abstract: BACKGROUND
  Sacral plexus avulsions lead to severe disability in patients and remain a thorny clinical problem due to the lack of anatomical, experimental and clinical studies. Attempts have been made to treat lumbosacral plexus injuries with such operations as direct anastomosis of the ends of injured sacral plexuses, and certain therapeutic effects were achieved. To further explore the degeneration pattern of anterior cornual motoneurons and determine the best time for treatment, we carried out this study.
  
  
  METHODS
  We randomly assigned 60 SD rats into six groups (group A-F), with ten rats per group. The A, B, C, D, E, F groups included animals that received operation for L4-L6 nerve root avulsion at 2, 4, 6, 8, 10 and 12 weeks respectively. We measured the apoptosis of motor neurons in the anterior corn through hematoxylin-eosin (HE) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and found that after sacral plexus avulsions, motor neurons in the anterior horn of the spinal cord gradually reduced and the apoptosis index gradually increased as the time went by.
  
  
  RESULTS
  Survival rates of motoneurons at 2, 4, 6, 8, 10, and 12 weeks after avulsion were (92.1 ± 4.7)%, (83.6 ± 3.7)%, (43.6 ± 4.2)%, (32.1 ± 3.5)%, (18.4 ± 3.7)% and (12.1 ± 3.3)%, respectively. The difference was most significant at week 6.
  
  
  CONCLUSIONS
  Week 6 after injury is probably the deadline for surgical repair of sacral plexus avulsions.
authors.affiliation: Department of Orthopedics Trauma Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Jiang
authors.forename: Xiao
authors.initials: X
authors.lastname: Chen
authors.forename: Di
authors.initials: D
authors.lastname: Shen
authors.forename: Aimin
authors.initials: A
authors.lastname: Chen
mesh_terms: D000818:Animals; D017209:Apoptosis; D008160:Lumbosacral Plexus / Q000293:injuries* / Q000473:pathology; D008297:Male; D009046:Motor Neurons / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000473:pathology*