Manual stimulation, but not acute electrical stimulation prior to reconstructive surgery, improves functional recovery after facial nerve injury in rats.
The outcome of peripheral nerve injuries requiring surgical repair is poor. Recent work suggested that electrical stimulation (ES) of the proximal nerve stump to produce repeated discharges of the parent motoneurons for one hour could be a beneficial therapy if delivered immediately prior to reconstructive surgery of mixed peripheral nerves.


OBJECTIVE
We tested whether ES has a positive influence on functional recovery after repair of a purely motor nerve, the facial nerve.


METHODS
Electrical stimulation (20 Hz) was delivered to the proximal nerve stump of the transected facial nerve for 1 hour prior to nerve reconstruction by end-to-end suture (facial-facial anastomosis, FFA). For manual stimulation (MS), animals received daily rhythmic stroking of the whisker pads. Restoration of vibrissal motor performance following ES or MS was evaluated using video-based motion analysis. We also assessed the degree of collateral axonal branching at the lesion site, by counting motoneuronal perikarya after triple retrograde labeling, and estimated the quality of motor end-plate reinnervation in the target musculature. Outcomes at 4 months were compared to animals receiving sham stimulation (SS) or MS.


RESULTS
Neither protocol reduced the degree of collateral sprouting. ES did not improve functional outcome and failed to reduce the proportion of polyinnervated motor end-plates. By contrast, MS restored normal whisking function and reduced polyinnervation.


CONCLUSIONS
Whereas acute ES is not beneficial for facial nerve repair, MS provides long-term benefits.
Skouras
Emmanouil
E
Department of Trauma, Hand and Reconstructive Surgery, University of Cologne, Cologne, Germany.
Merkel
Daniel
D
Grosheva
Maria
M
Angelova
Srebrina K
SK
Schiffer
Gereon
G
Thelen
Ulrich
U
Kaidoglou
Katerina
K
Sinis
Nektarios
N
Igelmund
Peter
P
Dunlop
Sarah A
SA
Pavlov
Stoyan
S
Irintchev
Andrey
A
Angelov
Doychin N
DN
D000596:Amino Acids; D000818:Animals; D001703:Biophysics; D004195:Disease Models, Animal; D004558:Electric Stimulation / Q000379:methods; D020220:Facial Nerve Injuries / Q000503:physiopathology / Q000534:rehabilitation* / Q000601:surgery*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D026201:Musculoskeletal Manipulations / Q000379:methods*; D009416:Nerve Regeneration / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D019651:Plastic Surgery Procedures / Q000379:methods; D020127:Recovery of Function / Q000502:physiology*; D013266:Stilbamidines; D013997:Time Factors; D014738:Vibrissae / Q000294:innervation
C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D000596:Amino Acids; D013266:Stilbamidines; C098463:dolaisoleucine