Obstetric brachial plexus palsy: a comparison of the degree of recovery after repair of a C6 ventral root avulsion in newborn and adult sheep.
The C6 motor rootlets were avulsed from the spinal cord in six newborn lambs to simulate a birth lesion of the upper root of the brachial plexus. Six 1-year-old sheep were used for comparison, and treated in a similar manner. The injury was repaired immediately in each group using an autologous coaxial freeze-thawed skeletal muscle graft. The animals were allowed to recover for 1 year after the surgery. The C6 root was then examined electrophysiologically and morphologically. The results were compared with those obtained from a group of untreated intact 1-year-old sheep. The fibre and axon diameters and myelin sheath thickness were significantly different in the group repaired as lambs when compared with the group repaired at the age of 1 year. There was also a significantly increased maximum conduction velocity and a greater range of conduction velocities within the nerve in the lambs. Central motor latency was significantly slower in the sheep than in the lambs. These findings would suggest a greater potential for recovery in the lambs after brachial plexus root avulsion injuries.
Fullarton
A C
AC
Department of Clinical Neurosciences, University of Edinburgh, Western General Hospital, Edinburgh, UK.
Myles
L M
LM
Lenihan
D V
DV
Hems
T E
TE
Glasby
M A
MA
D000367:Age Factors; D000818:Animals; D020516:Brachial Plexus Neuropathies / Q000209:etiology / Q000601:surgery*; D002572:Cervical Plexus / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D004594:Electrophysiology; D005260:Female; D009416:Nerve Regeneration; D009431:Neural Conduction; D010246:Paralysis, Obstetric / Q000601:surgery*; D011247:Pregnancy; D011843:Radiculopathy / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D011930:Reaction Time; D012756:Sheep