title: Different effects of tetanic stimulation of facial nerve and ulnar nerve on transcranial electrical stimulation motor-evoked potentials.
abstract: OBJECTIVE
  Our objective was to examine whether prior tetanic stimulation of cranial nerves enhances the amplitudes of transcranial motor-evoked potentials (MEPs).
  
  
  METHODS
  Thirty patients undergoing elective craniotomy under propofol-fentanyl anesthesia with partial neuromuscular blockade were enrolled. Both control and posttetanic MEPs (c-MEPs and p-MEPs) monitoring were performed with a train of five pulses delivered to C3 or C4. c-MEPs were recorded from target muscles and p-MEPs were obtained 1 s after tetanic stimulation to the ulnar nerves and facial nerves. The amplitudes of paired MEPs were compared with Wilcoxon's signed rank test.
  
  
  RESULTS
  When tetanic stimulation was separately applied to the facial nerves, amplitudes of p-MEPs from abductor pollicis brevis, orbicularis oculi or oris were similar with those of c-MEPs. When tetanic stimulations were separately applied to the ulnar nerves, the amplitudes of p-MEPs from the abductor pollicis brevis but not orbicularis oculi or oris were significantly enlarged compared with c-MEP.
  
  
  CONCLUSIONS
  We found that only prior tetanic stimulation of ulnar nerve but not facial nerve could enlarge the amplitudes of trancranial hand MEPs. Augmentation of MEP amplitude via prior tetanic stimulation of peripheral nerve seems to originate from the subcortical level but not motor cortex.
authors.affiliation: Department of Anesthesiology, Obstetrics and Gynecology Hospital, Fudan University Shanghai 200090, China.
authors.forename: Shen
authors.initials: S
authors.lastname: Sun
authors.affiliation: Department of Anesthesiology, Obstetrics and Gynecology Hospital, Fudan University Shanghai 200090, China.
authors.forename: Fu-Bo
authors.initials: FB
authors.lastname: Tian
authors.affiliation: Department of Anesthesiology, Obstetrics and Gynecology Hospital, Fudan University Shanghai 200090, China.
authors.forename: Shao-Qang
authors.initials: SQ
authors.lastname: Huang
authors.affiliation: Department of Anesthesiology, Huashan Hospital, Fudan University Shanghai 200040, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Anesthesiology, Huashan Hospital, Fudan University Shanghai 200040, China.
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Liang
keywords: Motor-evoked potentials; abductor pollicis brevis; facial nerve; orbicularis oculi; orbicularis oris; tetanic stimulation; ulnar nerve
references.citation: Clin Neurophysiol. 1999 Apr;110(4):720-4
references.pmid: 10378744
references.citation: J Neurol Neurosurg Psychiatry. 2010 May;81(5):519-23
references.pmid: 19726411
references.citation: J Neurosurg. 2004 Jan;100(1):155-60
references.pmid: 14743930
references.citation: Neurosurgery. 1992 Aug;31(2):298-305
references.pmid: 1513434
references.citation: Spine (Phila Pa 1976). 2008 Dec 15;33(26):E994-E1000
references.pmid: 19092611
references.citation: Skull Base. 2010 Nov;20(6):429-34
references.pmid: 21772800
references.citation: Anesth Analg. 2007 Jun;104(6):1488-92, table of contents
references.pmid: 17513647
references.citation: Anesth Analg. 1996 Mar;82(3):593-9
references.pmid: 8623967
references.citation: Anesth Analg. 2008 Mar;106(3):930-4, table of contents
references.pmid: 18292442
references.citation: Anesthesiology. 2005 Apr;102(4):733-8
references.pmid: 15791101
references.citation: Exp Brain Res. 2002 Feb;142(4):562-9
references.pmid: 11845251
references.citation: Nat Neurosci. 1998 May;1(1):64-8
references.pmid: 10195111
references.citation: J Neurol Neurosurg Psychiatry. 2008 Sep;79(9):1066-70
references.pmid: 18245141
references.citation: Spine (Phila Pa 1976). 2007 Apr 15;32(8):911-7
references.pmid: 17426638
references.citation: Anesth Analg. 2008 Jul;107(1):215-20
references.pmid: 18635490
references.citation: Spine (Phila Pa 1976). 2000 Apr 15;25(8):974-9
references.pmid: 10767811
references.citation: Br J Anaesth. 2009 Jun;102(6):869-74
references.pmid: 19376787
references.citation: J Physiol. 2002 Apr 15;540(Pt 2):623-33
references.pmid: 11956348
references.citation: J Clin Monit Comput. 2013 Feb;27(1):35-46
references.pmid: 23015366
references.citation: J Neurosurg Anesthesiol. 2004 Jan;16(1):32-42
references.pmid: 14676568
references.citation: Electroencephalogr Clin Neurophysiol. 1996 Aug;101(4):263-72
references.pmid: 8761035
references.citation: J Anesth. 2009;23(2):175-81
references.pmid: 19444553
references.citation: Med Biol Eng Comput. 2004 Jan;42(1):110-3
references.pmid: 14977231
references.citation: Neurosurgery. 2010 Jun;66(6 Suppl Operative):354-61; discussion 362
references.pmid: 20514692
references.citation: Anesth Analg. 2006 Jun;102(6):1715-21
references.pmid: 16717315