title: Manual stimulation of facial muscles improves functional recovery after hypoglossal-facial anastomosis and interpositional nerve grafting of the facial nerve in adult rats.
abstract: The facial nerve in humans is often prone to injuries requiring surgical intervention. In the best case, nerve reconstruction is achieved by a facial-facial anastomosis (FFA), i.e. suture of the proximal and distal stumps of the severed facial nerve. Although a method of choice, FFA rarely leads to a satisfactory functional recovery. We have recently devised and validated, in an established experimental paradigm in rats, a novel strategy to improve the outcome of FFA by daily manual stimulation (MS) of facial muscles. This treatment results in full recovery of facial movements (whisking) and is achieved by reducing the proportion of functionally detrimental poly-innervated motor end-plates. Here we asked whether MS could also be beneficial after two other commonly used surgical methods of clinical facial nerve reconstruction namely hypoglossal-facial anastomosis (HFA) and interpositional nerve grafting (IPNG) which, however, seem to have a poorer outcome compared to FFA. Compared to FFA, daily MS for 2 months after HFA and IPGN did not completely restore function but, nevertheless, significantly improved the amplitude of whisker movements by 50% compared with untreated animals. Functional improvement was associated with a reduction in the proportion of polyinnervated end-plates. MS did not reduce the extent of axonal branching at the lesion site nor the subsequent misdirected axonal regrowth to inappropriate targets. Our data show that a simple approach leading to improved quality of muscle fiber reinnervation is functionally beneficial after different types of clinically relevant surgical interventions.
authors: Department of Otorhinolaryngology, Friedrich-Schiller University Jena, D-07740 Jena, Germany.
authors: Orlando
authors: O
authors: Guntinas-Lichius
authors: Gregor
authors: G
authors: Hundeshagen
authors: Thomas
authors: T
authors: Paling
authors: Michael
authors: M
authors: Streppel
authors: Maria
authors: M
authors: Grosheva
authors: Andrey
authors: A
authors: Irintchev
authors: Emmanouil
authors: E
authors: Skouras
authors: Athanasia
authors: A
authors: Alvanou
authors: Srebrina K
authors: SK
authors: Angelova
authors: Stefanie
authors: S
authors: Kuerten
authors: Nektarios
authors: N
authors: Sinis
authors: Sarah A
authors: SA
authors: Dunlop
authors: Doychin N
authors: DN
authors: Angelov
mesh_terms: D000714:Anastomosis, Surgical; D000818:Animals; D019771:Axotomy; D005152:Facial Muscles / Q000294:innervation* / Q000502:physiology*; D005154:Facial Nerve / Q000502:physiology; D020220:Facial Nerve Injuries / Q000601:surgery*; D005260:Female; D007002:Hypoglossal Nerve / Q000601:surgery*; D009121:Muscle Denervation; D026201:Musculoskeletal Manipulations; D009416:Nerve Regeneration / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function / Q000502:physiology*; D019737:Transplants; D016896:Treatment Outcome; D014738:Vibrissae / Q000502:physiology