Accelerating functional recovery after rat facial nerve injury: Effects of gonadal steroids and electrical stimulation.
OBJECTIVE
We investigated the combined effects of electrical stimulation and testosterone propionate on overall recovery time in rats with extracranial crush injuries to the facial nerve.


METHODS
Male rats underwent castration 3 to 5 days prior to right facial nerve crush injury and electrode implantation. Rats were randomly assigned to two groups: crush injury + testosterone or crush injury with electrical stimulation + testosterone. Recovery was assessed by daily subjective examination documenting vibrissae orientation/movement, semi-eye blink, and full eye blink.


RESULTS
Milestones of early recovery were noted to be significantly earlier in the groups with electrical stimulation, with/without testosterone. The addition of testosterone to electrical stimulation showed significant earlier return of late recovery parameters and complete overall recovery.


CONCLUSIONS
Electrical stimulation may decrease cell death or promote sprouting to accelerate early recovery. Testosterone may affect the actual rate of axonal regeneration and produce acceleration in functional recovery. By targeting different stages of neural regeneration, the synergy of electrical stimulation and testosterone appears to have promise as a neurotherapeutic strategy for facial nerve injury.
Hetzler
Laura E T
LE
Department of Otolaryngology-Head & Neck Surgery, Loyola University Medical Center, Maywood, IL 60153, USA. thehetzlers@gmail.com
Sharma
Nijee
N
Tanzer
Lisa
L
Wurster
Robert D
RD
Leonetti
John
J
Marzo
Sam J
SJ
Jones
Kathryn J
KJ
Foecking
Eileen M
EM
D000818:Animals; D003131:Combined Modality Therapy; D004599:Electric Stimulation Therapy; D004567:Electrodes, Implanted; D020220:Facial Nerve Injuries / Q000628:therapy*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D043343:Testosterone Propionate / Q000008:administration & dosage / Q000627:therapeutic use*; D014945:Wound Healing / Q000187:drug effects / Q000502:physiology
D043343:Testosterone Propionate