EP 19. Quantitative EMG analysis of nerve regeneration after reconstruction of the facial nerve by hypoglossal-facial nerve jump anastomosis. Issue 9 (September 2016)

• Record Type: Journal Article
• Authors: Flasar, J.; Volk, G.F.; Lehmann, T.; Irintchev, A.; Guntinas-Lichius, O.
• Is Part Of: Clinical neurophysiology. Volume 127:Issue 9(2016:Sep.)
• Page Start: e240
• Page End: e241
• Publication Date: 2016-09
• Subjects: Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2016.05.073
• Languages: English
• ISSNs: 1388-2457

Abstract

Abstract : Introduction: Although electromyography (EMG) provides accurate information of the reinnervation of muscles, there are almost no quantitative data, that would describe this process in the facial muscles after a reconstruction of the facial nerve. Using the example of reinnervation surgery of the facial nerve quantitative data are presented here for the first time. Materials and methods: Needle-EMG data of 11 patients with a hypoglossal-facial nerve jump anastomosis (HFJA) were retrospectively evaluated. The main object of the quantitative measurements were 3 EMG-parameters of the motor unit action potentials (MUAP): amplitude, duration, polyphasia. Contralateral healthy sites of the faces of six patients were evaluated on the same principles as at the patients for the purpose of control. These data were correlated with the Stennert-index of the patients, that was simultaneously assessed with the needle EMG-evaluation. Results: A total of 1025 action potentials of 308 motor units were measured. The amplitudes of the MUAPs showed a steady increase of the amplitudes and in the extension of the duration of the amplitudes over 2 years in the course of regeneration after HFJA. The duration rose clearly earlier than the height of the amplitude. There was a significant correlation between height of the amplitudes and the Stennert index. An improvement in the Stennert index by one point corresponded to an increase in the height of an amplitude to 112.793 microvolts ( p = 0.001). A subanalysis of the Stennert index during mimic movements and the Stennert index at rest showed, that Stennert index at rest correlated stronger ( r = 139, 8; p = 0.002) with the increase of the amplitude than Stennert index during movements ( r = 57, 0; p = 0.323). Conclusions: The increase in the height of the amplitude appears to be the most powerful indicator of an improvement of the clinical condition. In order to assess the progress of a facial nerve reinnervation, both the increase in the amplitude, but also the duration can be used. The reinnervation can last clinically and electrophysiologically up to two years after surgery. This is important for the planning of a further rehabilitation as well as for a patient education.