title: Outcome-dependent coactivation of lip and tongue primary somatosensory representation following hypoglossal-facial transfer after peripheral facial palsy.
abstract: A hypoglossal-facial transfer is a common surgical strategy for reanimating the face after persistent total hemifacial palsy. We were interested in how motor recovery is associated with cortical reorganization of lip and tongue representation in the primary sensorimotor cortex after the transfer. Therefore, we used functional magnetic resonance imaging (fMRI) in 13 patients who underwent a hypoglossal-facial transfer after unilateral peripheral facial palsy. To identify primary motor and somatosensory tongue and lip representation sites, we measured repetitive tongue and lip movements during fMRI. Electromyography (EMG) of the perioral muscles during tongue and lip movements and standardized evaluation of lip elevation served as outcome parameters. We found an association of cortical representation sites in the pre- and postcentral gyrus (decreased distance of lip and tongue representation) with symmetry of recovered lip movements (lip elevation) and coactivation of the lip during voluntary tongue movements (EMG-activity of the lip during tongue movements). Overall, our study shows that hypoglossal-facial transfer resulted in an outcome-dependent cortical reorganization with activation of the cortical tongue area for restituded movement of the lip.
authors.affiliation: Functional Imaging Department, Institute of Diagnostic Radiology and Neuroradiology, University of Greifswald, Germany; Department of Neurosurgery, University of Greifswald, Greifswald, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Rottler
authors.forename: Henry W S
authors.initials: HW
authors.lastname: Schroeder
authors.forename: Martin
authors.initials: M
authors.lastname: Lotze
mesh_terms: D000368:Aged; D001931:Brain Mapping; D004576:Electromyography; D005154:Facial Nerve / Q000601:surgery*; D005158:Facial Paralysis / Q000601:surgery*; D005260:Female; D006801:Humans; D007002:Hypoglossal Nerve / Q000601:surgery*; D007091:Image Processing, Computer-Assisted; D008046:Lip / Q000294:innervation*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000098:blood supply / Q000502:physiology*; D016067:Nerve Transfer / Q000379:methods*; D009460:Neurologic Examination; D010100:Oxygen / Q000097:blood; D013003:Somatosensory Cortex / Q000098:blood supply / Q000502:physiology*; D014059:Tongue / Q000294:innervation* / Q000502:physiology; D016896:Treatment Outcome
chemical_list: D010100:Oxygen
keywords: cortical reorganization; facial palsy; functional magnetic resonance imaging (fMRI); hypoglossal-facial transfer; primary motor cortex (M1); primary somatosensory cortex (S1)