title: Train-of-four test in intraoperative neurophysiologic monitoring: differences between hand and foot train-of-four.
abstract: OBJECTIVE
  Comparison of T1-T4 decrement between upper and lower extremity muscles can indicate differences between recovery time from neuromuscular blockade, which may have repercussions for neurophysiologic intraoperative monitoring. We investigated decrement between T1 and T4 hand and foot muscle responses on quantitative train-of-four (TOF) test.
  
  
  METHODS
  Study analyzed differences between recovery of foot, abductor hallucis muscle, and hand, first dorsal interosseous muscle, by application of quantitative TOF test on 147 patients undergoing lumbar spine surgery. T1 to T4 decrements on hand and foot TOF were obtained and classified into different groups, depending on elapsed time after administration of neuromuscular blocking agents and its dose.
  
  
  RESULTS
  There are significant differences between T1-T4 decrements obtained on hand and foot (P < 0.05). T1-T4 decrement determined on abductor hallucis muscle was lower indicating more rapid recovery than the first dorsal interosseous muscle (P < 0.05). Interestingly, quite opposite, more pronounced decrement in foot TOF than hand was showed in 4% (5 out of all 147 cases).
  
  
  CONCLUSIONS
  The observed difference between recovery of hand and foot muscles suggests that quantitative TOF test should be performed on extremities for which accurate data about the level of neuromuscular blockade is sought. During lumbar spine surgery monitoring, in addition to hand TOF, foot TOF should be included.
authors.affiliation: *Department of Clinical Neurophysiology, NYU Langone Medical Center, New York, New York, U.S.A.; and †Division of Clinical Neurophysiology, Department of Neurology, NYU School of Medicine, New York, New York, U.S.A.
authors.forename: Brane
authors.initials: B
authors.lastname: Gavrancic
authors.forename: Athena
authors.initials: A
authors.lastname: Lolis
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Beric
mesh_terms: D004558:Electric Stimulation; D019054:Evoked Potentials, Motor; D005528:Foot; D006225:Hand; D006801:Humans; D064795:Intraoperative Neurophysiological Monitoring / Q000379:methods*; D008159:Lumbar Vertebrae / Q000503:physiopathology / Q000601:surgery*; D018482:Muscle, Skeletal / Q000294:innervation*; D019148:Neuromuscular Blockade; D061886:Neuromuscular Monitoring; D009519:New York City; D011237:Predictive Value of Tests; D011446:Prospective Studies; D020127:Recovery of Function; D013123:Spinal Fusion; D013997:Time Factors; D016896:Treatment Outcome