The weepy cry

• Verfasst von: Munk, Philipp [VerfasserIn]
• Verfasst von: Merkelbach, Mick [VerfasserIn]
• Verfasst von: Lamadé, Wolfram [VerfasserIn]
• Titel: The weepy cry
• Titelzusatz: short neural signal bursts in intraoperative neuromonitoring
• Verf.angabe: Philipp C.B. Munk, Mick E. Merkelbach, Wolfram Lamadé
• E-Jahr: 2024
• Jahr: 22 March 2024
• Umfang: 10 S.
• Illustrationen: Illustrationen
• Fussnoten: Gesehen am 15.07.2024
• Titel Quelle: Enthalten in: Langenbeck's archives of surgery
• Ort Quelle: Berlin : Springer, 1948
• Jahr Quelle: 2024
• Band/Heft Quelle: 409(2024), Artikel-ID 102, Seite 1-10
• ISSN Quelle: 1435-2451
• DOI: doi:10.1007/s00423-024-03240-z
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: In-vitro
• Sach-SW: Intraoperative neuromonitoring
• Sach-SW: Nerve conduction studies
• Sach-SW: Recurrent laryngeal nerve palsy
• K10plus-PPN: 1895440610

Abstract

Purpose: This study aimed to establish an in-vitro alternative to existing in-vivo systems to analyze nerve dysfunction using continuous neuromonitoring (C-IONM). Methods: Three hundred sixty-three recurrent laryngeal nerves (RLN) (N(pigs) = 304, N(cattle) = 59) from food industry cadavers were exposed by microsurgical dissection following euthanasia. After rinsing with Ringer's lactate, they were tempered at 22 °C. Signal evaluation using C-IONM was performed for 10 min at 2 min intervals, and traction forces of up to 2N were applied for a median time of 60 s. Based on their post-traumatic electrophysiological response, RLNs were classified into four groups: Group A: Amplitude ≥ 100%, Group B: loss of function (LOS) 0–25%, Group C: ≥ 25–50%, and Group D: > 50%. Results: A viable in-vitro neuromonitoring system was established. The median post-traumatic amplitudes were 112%, 88%, 59%, and 9% in groups A, B, C, and D, respectively. A time-dependent further dynamic LOS was observed during the 10 min after cessation of strain. Surprisingly, following initial post-traumatic hyperconductivity, complete LOS occurred in up to 20% of the nerves in group A. The critical threshold for triggering LOS was 2N in all four groups, resulting in immediate paralysis of up to 51.4% of the nerves studied. Conclusion: Consistent with in-vivo studies, RLN exhibit significant intrinsic electrophysiological variability in response to tensile forces. Moreover, nerve damage progresses even after the complete cessation of strain. Up to 20% of nerves with transiently increased post-traumatic amplitudes above 100% developed complete LOS, which we termed the "weepy cry." This time-delayed response must be considered during the interpretation of C-IONM signals.