Subthreshold continuous electrical stimulation facilitates functional recovery of facial nerve after crush injury in rabbit.
We sought to determine whether electrical stimulation (ES) with subthreshold, continuous, low-frequency impulses is a viable clinical method for improving functional recovery after facial nerve crush injury. In 10 rabbits, bilateral crush injuries were made on the facial nerve by compression for 30 s with mosquito forceps, causing complete facial paralysis. Subthreshold continuous direct current ES with 20-Hz square-wave pulses was applied to the proximal stump on one side for 4 weeks. Vibrissae movement returned significantly earlier on the ES side, with a less variable recovery time. Electrophysiologically, the stimulated side had a significantly shorter latency, longer duration, and faster conduction velocity. Light and transmission electron microscopy revealed that the electrical stimulation also markedly decreased Wallerian degeneration. The average numbers of fluorescent, double-labeled nerve cells were significantly different between the ES and non-ES sides. This study shows that subthreshold, continuous, low-frequency ES immediately after a crush injury of the facial nerve results in earlier recovery of facial function and shorter overall recovery time.
Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul 120-752, Korea.
Jin
J
Kim
Su Jin
SJ
Han
Dong Hyun
DH
Shin
Won-Sang
WS
Lee
Jae Young
JY
Choi
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001572:Benzofurans; D001703:Biophysics / Q000379:methods; D003911:Dextrans; D004195:Disease Models, Animal; D004599:Electric Stimulation Therapy / Q000379:methods*; D004594:Electrophysiology; D005154:Facial Nerve / Q000502:physiology* / Q000503:physiopathology / Q000648:ultrastructure; D020220:Facial Nerve Injuries / Q000503:physiopathology / Q000628:therapy*; D007839:Functional Laterality; D008297:Male; D046529:Microscopy, Electron, Transmission / Q000379:methods; D009068:Movement / Q000502:physiology; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology; D009431:Neural Conduction / Q000502:physiology; D011817:Rabbits; D020127:Recovery of Function / Q000502:physiology*; D012235:Rhodamines; D018709:Statistics, Nonparametric; D014738:Vibrissae / Q000294:innervation
D001572:Benzofurans; D003911:Dextrans; C067661:Fluoro-Ruby; D012235:Rhodamines; C038675:true blue