Ashraf Raslan1,2,3, Orlando Guntinas-Lichius1,4, Gerd Fabian Volk1,4. 1. Department of Otorhinolaryngology, Jena University Hospital, Jena, Germany. 2. Department of Otorhinolaryngology, Assiut University Hospital, Assiut, Egypt. 3. Department of Otorhinolaryngology, Ilm-Kreis Clinics, Arnstadt, Germany. 4. Facial Nerve Center Jena, Jena University Hospital, Jena, Germany.
Abstract
OBJECTIVES/HYPOTHESIS: Using surface electrostimulation, we aimed to use facial nerve mapping (FNM) in healthy subjects and patients with postparetic facial synkinesis (PPFS) to define functional facial target regions that can be stimulated selectively. STUDY DESIGN: Single-center prospective cohort study. METHODS: FNM was performed bilaterally in 20 healthy subjects and 20 patients with PPFS. Single-pulse surface FNM started at the main trunk of the facial nerve and followed the peripheral branches in a distal direction. Stimulation started with 0.1 mA and increased in 0.1 mA increments. The procedure was simultaneously video recorded and evaluated offline. RESULTS: A total of 1,873 spots were stimulated, and 1,875 facial movements were evaluated. The stimulation threshold was higher on the PPFS side (average = 9.8 ± 1.0 mA) compared to the contralateral side (4.1 ± 0.8 mA) for all stimulation sites or compared to healthy subjects (4.1 ± 0.5 mA; all P < .01). In healthy subjects, selective electrostimulation ± one unintended coactivation was possible at all sites in >80% of cases, with the exception of pulling up the corner of the mouth (65%-75%). On the PPFS side, stimulation was possible for puckering lips movements in 60%/75% (selective stimulation ± one coactivation, respectively), blinking in 55%/80%, pulling up the corner of the mouth in 50%/85%, brow raising in 5%/85, and raising the chin in 0%/35% of patients, respectively. CONCLUSIONS: FNM mapping for surgical planning and selective electrostimulation of functional facial regions is possible even in patients with PPFS. FNM may be a tool for patient-specific evaluation and placement of electrodes to stimulate the correct nerve branches in future bionic devices (e.g., for a bionic eye blink). LEVEL OF EVIDENCE: 2b Laryngoscope, 130:E320-E326, 2020.
OBJECTIVES/HYPOTHESIS: Using surface electrostimulation, we aimed to use facial nerve mapping (FNM) in healthy subjects and patients with postparetic facial synkinesis (PPFS) to define functional facial target regions that can be stimulated selectively. STUDY DESIGN: Single-center prospective cohort study. METHODS: FNM was performed bilaterally in 20 healthy subjects and 20 patients with PPFS. Single-pulse surface FNM started at the main trunk of the facial nerve and followed the peripheral branches in a distal direction. Stimulation started with 0.1 mA and increased in 0.1 mA increments. The procedure was simultaneously video recorded and evaluated offline. RESULTS: A total of 1,873 spots were stimulated, and 1,875 facial movements were evaluated. The stimulation threshold was higher on the PPFS side (average = 9.8 ± 1.0 mA) compared to the contralateral side (4.1 ± 0.8 mA) for all stimulation sites or compared to healthy subjects (4.1 ± 0.5 mA; all P < .01). In healthy subjects, selective electrostimulation ± one unintended coactivation was possible at all sites in >80% of cases, with the exception of pulling up the corner of the mouth (65%-75%). On the PPFS side, stimulation was possible for puckering lips movements in 60%/75% (selective stimulation ± one coactivation, respectively), blinking in 55%/80%, pulling up the corner of the mouth in 50%/85%, brow raising in 5%/85, and raising the chin in 0%/35% of patients, respectively. CONCLUSIONS: FNM mapping for surgical planning and selective electrostimulation of functional facial regions is possible even in patients with PPFS. FNM may be a tool for patient-specific evaluation and placement of electrodes to stimulate the correct nerve branches in future bionic devices (e.g., for a bionic eye blink). LEVEL OF EVIDENCE: 2b Laryngoscope, 130:E320-E326, 2020.
Authors: Orlando Guntinas-Lichius; Gerd Fabian Volk; Kerry D Olsen; Antti A Mäkitie; Carl E Silver; Mark E Zafereo; Alessandra Rinaldo; Gregory W Randolph; Ricard Simo; Ashok R Shaha; Vincent Vander Poorten; Alfio Ferlito Journal: Eur Arch Otorhinolaryngol Date: 2020-04-08 Impact factor: 2.503