Cerebral plasticity after hypoglosso-facial anastomosis in facial palsy: a magnetoencephalography study

  1. Rémi Hervochon
  2. Deborah Ziri
  3. Guillaume Dupuch
  4. Maximilien Chaumon
  5. Claire Foirest
  6. Denis Schwartz
  7. Christophe Gitton
  8. Nathalie George
  9. Frédéric Tankere
Read the full article See related articles

Listed in

This article is not in any list yet, why not save it to one of your lists.
Log in to save this article

Abstract

Background.

Hypoglosso-facial anastomosis (HFA) consists in suturing the proximal part of the hypoglossal nerve with the distal part of the facial nerve in patients with facial palsy. Axonal regrowth through the anastomosis makes it possible to restore facial motor skills, which become spontaneous after physiotherapy. This suggests cerebral plasticity.

Objective

We used magnetoencephalography (MEG) in a pilot study to test this hypothesis

Methods

Twenty-one healthy volunteers (CTRL) and 12 patients after HFA performed 5 motor tasks with MEG and electromyographic recordings: eyelid closure, smile, tongue protraction, mastication and thumb flexion. For each task, we picked the location of the maximum source activity within the precentral gyrus. We calculated the distances between this location and the vertex for each task and a somatotopy index.

Results

There was an interaction between the participant’s group and the task (F(4,124)=4.07, p=0.0039). In CTRL, the maximum source location was statistically different between smile and tongue tasks and between eyelid and tongue tasks (p<0.001). No such difference was observed in HFA (p=1.000). 90.5% of CTRL and 41.7% of HFA showed a normal somatotopy (p=0.0046).

Conclusions

In CTRL, the organization of the cortical motor areas was similar to that of Penfield’s motor Homunculus. In contrast, in HFA, eyelid closure, tongue protraction and smile areas were not significantly distinct. This supports the hypothesis of cerebral plasticity after HFA.

The Ethical Committee of Paris Idf VI approved the study (CPP Ouest 6-CPP975-HPS2).

Financial Disclosure Statement

  • –

    This research has received funding from the “ Fondation pour la Recherche Médicale ” and from the “ Fondation des Gueules Cassées ”. It was performed on a platform of the France Life Imaging network partly funded by the grant “ANR-11-INBS-0006” and by the program “Investissements d’avenir” ANR-10-IAIHU-06. The funding bodies had no role in the study design, the data collection, analysis or interpretation, or the article writing.

  • –

    The authors have neither commercial association nor financial disclosure.

    • Generative AI was not used

    Article activity feed

    1. Version published to 10.1101/2025.05.13.652175v1 on bioRxiv