title: Importance of latency and amplitude values of recurrent laryngeal nerve during thyroidectomy in diabetic patients.
abstract: BACKGROUND
  Diabetes mellitus may cause degeneration in the myelin and/or axonal structures of peripheral nerves. The aim of this study was to investigate the effects of diabetic neuropathy on intraoperative neuromonitoring findings such as latency and amplitude values of the recurrent laryngeal nerves during thyroidectomy. To our knowledge this is the first study to report comparison of the electrophysiologic features of diabetic and non-diabetic patients.
  
  
  METHODS
  One-hundred-and-eleven consecutive patients who received neuromonitoring during thyroidectomy between 2013 and 2015 were included to study. The patients were divided into two groups according to the presence of diabetes mellitus. Pre-thyroidectomy and post thyroidectomy motor response latency and amplitude values of recurrent laryngeal nerves were compared between groups. Neuromonitoring findings, demographic data and postoperative complications were evaluated.
  
  
  RESULTS
  The diabetic group consisted of 29 (26.1%) patients while 82 (73.9%) patients were in non-diabetic group. The mean post-thyroidectomy amplitude values (millivolts-mV) of the recurrent laryngeal nerve were significantly lower in diabetic group (0.51 ± 0.26 mV vs. 0,70 ± 0,46 mV, p < 0.05), whereas the latency values were significantly higher (2.50 ± 0.86 ms vs. 1.85 ± 0.59 ms, p < 0.01) compared to non-diabetic group. Additionally, post-thyroidectomy latency values were significantly increased compared to the pre-thyroidectomy latency values (2.50 ± 0.86 ms vs. 2.02 ± 0.43 ms) in diabetic group patients (p < 0.05). Although postoperative complication rates were higher in diabetic group (10.3% vs. 5.9%), there were no statistical significance differences.
  
  
  CONCLUSIONS
  Prolonged latency and decreased amplitude values in recurrent laryngeal nerves of diabetic patients show that diabetic neuropathy of the recurrent laryngeal nerves develop similarly to the peripheral nerves. Increased post-thyroidectomy latency values reveal that the recurrent laryngeal nerve is more susceptible to surgical trauma in diabetic patients.
authors.affiliation: Istanbul Medeniyet University, Goztepe Training & Research Hospital, Department of General Surgery, Istanbul, Turkey. Electronic address: draliozemir@hotmail.com.
authors.forename: Ibrahim Ali
authors.initials: IA
authors.lastname: Ozemir
authors.affiliation: Istanbul Medeniyet University, Goztepe Training & Research Hospital, Department of General Surgery, Istanbul, Turkey.
authors.forename: Ferman
authors.initials: F
authors.lastname: Ozyalvac
authors.affiliation: Istanbul Medeniyet University, Goztepe Training & Research Hospital, Department of General Surgery, Istanbul, Turkey.
authors.forename: Gorkem
authors.initials: G
authors.lastname: Yildiz
authors.affiliation: Istanbul Medeniyet University, Goztepe Training & Research Hospital, Department of General Surgery, Istanbul, Turkey.
authors.forename: Tunc
authors.initials: T
authors.lastname: Eren
authors.affiliation: Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Aydin-Ozemir
authors.affiliation: Istanbul Medeniyet University, Goztepe Training & Research Hospital, Department of General Surgery, Istanbul, Turkey.
authors.forename: Orhan
authors.initials: O
authors.lastname: Alimoglu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003929:Diabetic Neuropathies / Q000150:complications / Q000503:physiopathology*; D055724:Electrophysiological Phenomena; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D011446:Prospective Studies; D012009:Recurrent Laryngeal Nerve / Q000502:physiology / Q000503:physiopathology*; D061226:Recurrent Laryngeal Nerve Injuries / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control; D013959:Thyroid Diseases / Q000150:complications / Q000601:surgery*; D013965:Thyroidectomy / Q000009:adverse effects*; D014826:Vocal Cord Paralysis / Q000209:etiology; D055815:Young Adult
keywords: Amplitude; Diabetes mellitus; Latency; Recurrent laryngeal nerve