title: Intra-Operative Neural Response Telemetry and Acoustic Reflex Assessment using an Advance-In-Stylet Technique and Modiolus-Hugging: A prospective cohort study.
abstract: OBJECTIVE
  The development of cochlear implant (CI) electrode arrays has focused on the use of a minimally invasive technique involving a modiolus-hugging placement of the electrode. The aim of this study was to evaluate the "advance-in-stylet" (AIS) technique compared to the advance-off-stylet (AOS) technique recommended for the current cochlear Nucleus(®) device. In the AIS technique, the stylet is not removed. We evaluated the electrical auditory thresholds measured when the stylet was removed (modiolus-hugging) compared to measurements taken with the stylet in place (lateral wall cochlea electrode placement).
  
  
  METHODS
  In this prospective cohort study, 30 consecutive patients received unilateral Nucleus Freedom(®) CIs using AIS insertion. Measurement of the acoustic reflex (AR) and neural response telemetry (NRT) were performed with the stylet in place (lateral wall placement of the electrodes) and then removed (perimodiolar placement), and the results compared. The responses were measured in the basal, middle and apical turns in both groups-with and without stylet.
  
  
  RESULTS
  The AIS surgery was completed without complication in 30 patients (16 males and 14 females, age range 3-54 years [mean 11]). Based on neural response telemetry, only apical electrodes showed statistically significant differences in thresholds, but the AR was not significantly different before or after stylet removal in any of the electrode groups tested.
  
  
  CONCLUSIONS
  The effects of modiolus-hugging do not seem to result in a large difference in electrical stimulation thresholds so, in difficult cases, the stylet may be left in place without significantly changing the thresholds, except perhaps at the apical turn.
authors.affiliation: Department of Otolaryngology, King Saud University and King Abdulaziz University Hospital, Riyadh, Saudi Arabia.
authors.forename: Abdulrahman
authors.initials: A
authors.lastname: Hagr
references.citation: Ann Otol Rhinol Laryngol. 1992 Apr;101(4):342-8
references.pmid: 1562140
references.citation: Otol Neurotol. 2005 Jul;26(4):620-3
references.pmid: 16015157
references.citation: Ann Otol Rhinol Laryngol. 1985 Jan-Feb;94(1 Pt 1):55-9
references.pmid: 3838226
references.citation: Laryngoscope. 2002 Sep;112(9):1653-6
references.pmid: 12352681
references.citation: Acta Otolaryngol. 2001 Jan;121(2):216-9
references.pmid: 11349782
references.citation: Ear Hear. 2003 Apr;24(2):184-90
references.pmid: 12677114
references.citation: Laryngoscope. 2005 Jun;115(6):977-82
references.pmid: 15933504
references.citation: Laryngoscope. 2004 Jan;114(1):71-6
references.pmid: 14709998
references.citation: Ear Hear. 1999 Feb;20(1):45-59
references.pmid: 10037065
references.citation: Ann Otol Rhinol Laryngol. 1991 Oct;100(10):807-11
references.pmid: 1952646
references.citation: Hear Res. 1993 Mar;66(1):108-20
references.pmid: 8473242
references.citation: Otolaryngol Head Neck Surg. 1981 Jan-Feb;89(1):125-30
references.pmid: 6784070
references.citation: Acta Otolaryngol. 2009 Nov;129(11):1330-6
references.pmid: 19863333
references.citation: Otol Neurotol. 2001 May;22(3):340-9
references.pmid: 11347637
references.citation: Ann Otol Rhinol Laryngol. 1983 Nov-Dec;92(6 Pt 1):610-3
references.pmid: 6689260
references.citation: Otol Neurotol. 2009 Jun;30(4):464-70
references.pmid: 19300297
references.citation: Ear Hear. 2002 Feb;23(1 Suppl):41S-48S
references.pmid: 11883766
references.citation: Am J Otol. 1997 Mar;18(2):179-83
references.pmid: 9093674
references.citation: Ear Hear. 2002 Feb;23(1 Suppl):28S-40S
references.pmid: 11883764
references.citation: Laryngoscope. 2003 Mar;113(3):415-9
references.pmid: 12616189
references.citation: Ear Hear. 2000 Apr;21(2):151-63
references.pmid: 10777022
references.citation: Acta Otolaryngol. 2000 Mar;120(2):214-7
references.pmid: 11603775
references.citation: Otol Neurotol. 2004 May;25(3):290-4
references.pmid: 15129107
references.citation: Acta Otolaryngol. 2002 Jun;122(4):363-9
references.pmid: 12125990
references.citation: Audiol Neurootol. 2003 May-Jun;8(3):166-75
references.pmid: 12679627
references.citation: Ear Hear. 2004 Dec;25(6):528-38
references.pmid: 15604914
references.citation: Otol Neurotol. 2006 Oct;27(7):918-22
references.pmid: 17006341
references.citation: Otol Neurotol. 2006 Dec;27(8):1083-8
references.pmid: 17130798
references.citation: Ear Hear. 1990 Feb;11(1):5-15
references.pmid: 2307303