Sensory and motor recovery after repairing transected cervical roots.
BACKGROUND
Adult mammal sensory axons avulsed through spinal dorsal root traction injuries, especially of the brachial plexus or cauda equina, cannot normally regenerate through axonal outgrowth from the DRG into the spinal cord, thus causing clinical conditions that require neuronal regeneration for sensory recovery and for which no successful treatment has yet been reported.


METHODS
To evaluate the sensory recovery of the forelimb after transection of their left cervical dorsal and ventral roots (C6-C8) at their spinal cord junctions, 22 SD rats were randomly assigned to 3 groups: transection only (control 1); transection followed by repair using intercostal nerve grafts and fibrin glue (control 2); transection, repair, and application of aFGF and fibrin glue (experimental group). The following tests were reperformed after retransecting the repaired nerve roots to discount collateral innervation from adjacent nerve roots: motor function (grasping power), mechanical sensitivity to pain and touch (foot-withdrawal response to mechanical stimuli), temperature sensitivity (foot-withdrawal response to cold stimulus), and electrophysiologic sensory responses (measurement of cortical SEP).


RESULTS
After transection and repair, the experimental group rats showed recovery in both motor (grasping power) and sensory (touch, pain, and temperature sensation) nerve functions. Neuronal regeneration was confirmed by the reappearance of cortical SEP and by its disappearance after retransection of the repaired cervical nerve roots.


CONCLUSIONS
Using our strategy for repairing transected cervical nerve roots, motor and sensory recovery was achieved in adult rats. The success of our study highlights possible treatment options for humans with avulsion injuries of the dorsal roots from the spinal cord.
Huang
Ming-Chao
MC
Department of Neurosurgery, Neural Regeneration Laboratory, Taipei Veterans General Hospital, Taipei 11217, Taiwan.
Chang
Pei-Teh
PT
Tsai
May-Jywan
MJ
Kuo
Huai-Sheng
HS
Kuo
Wen-Chun
WC
Lee
Meng-Jen
MJ
Lo
Ming-Jei
MJ
Lee
I-Hui
IH
Huang
Wen-Cheng
WC
Lee
Liang-Ming
LM
Shih
Yang-Hsin
YH
Lee
Liang-Shong
LS
Cheng
Henrich
H
D000818:Animals; D020516:Brachial Plexus Neuropathies / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D015718:Fibrin Tissue Adhesive / Q000627:therapeutic use; D016220:Fibroblast Growth Factor 1 / Q000627:therapeutic use; D020439:Growth Cones / Q000502:physiology / Q000648:ultrastructure; D018737:Hand Strength / Q000502:physiology; D007367:Intercostal Nerves / Q000637:transplantation; D009416:Nerve Regeneration / Q000187:drug effects; D009473:Neuronal Plasticity / Q000502:physiology; D019635:Neurosurgical Procedures / Q000379:methods; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology; D010243:Paralysis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D011843:Radiculopathy / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000187:drug effects; D019051:Rhizotomy; D020886:Somatosensory Disorders / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D013126:Spinal Nerve Roots / Q000187:drug effects* / Q000293:injuries / Q000601:surgery*; D019737:Transplants; D016896:Treatment Outcome
D015718:Fibrin Tissue Adhesive; D016220:Fibroblast Growth Factor 1