title: An improved electrical impedance myography (EIM) tongue array for use in clinical trials.
abstract: OBJECTIVE
  Electrical impedance myography (EIM) measurements of the tongue could provide valuable information about bulbar dysfunction in amyotrophic lateral sclerosis (ALS). A prototype tongue depressor EIM array produced gag reflexes. The objectives of this study were to determine the reliability, mean phase values, and tolerability of tongue EIM measurements using a smaller electrode array.
  
  
  METHODS
  Tongue EIM measurements were performed in a total of 31 healthy individuals and four neuromuscular patients with lingual abnormalities. Reliability was assessed by calculating the intraclass correlation coefficient (ICC) and percent difference in addition to performing Bland-Altman analyses. Standard descriptive statistics, including results of a Mann-Whitney test, were also determined.
  
  
  RESULTS
  At the 50 kHz frequency, the ICCs for intra- and inter-rater reliability were 0.76 with 5.17% difference and 0.78 with 5.34% difference respectively. The mean EIM phase values of healthy participants (11.61° ± 1.00°) and patients (9.87° ± 1.28°) were significantly different (p=0.0051). None of the participants experienced gag reflexes or discomfort.
  
  
  CONCLUSIONS
  The small tongue array provided good inter- and intra-rater reliability, could preliminarily distinguish between healthy and diseased muscle, and was well-tolerated.
  
  
  CONCLUSIONS
  Biomarker information about tongue health could be more comfortably obtained with a smaller EIM array.
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. Electronic address: cmcilduf@bidmc.harvard.edu.
authors.forename: Courtney
authors.initials: C
authors.lastname: McIlduff
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: Sung
authors.initials: S
authors.lastname: Yim
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Pacheck
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: Tom
authors.initials: T
authors.lastname: Geisbush
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Mijailovic
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: Seward B
authors.initials: SB
authors.lastname: Rutkove
mesh_terms: D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000503:physiopathology; D002986:Clinical Trials as Topic / Q000295:instrumentation*; D017097:Electric Impedance; D004576:Electromyography / Q000295:instrumentation* / Q000639:trends; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D039141:Muscular Dystrophy, Oculopharyngeal / Q000175:diagnosis* / Q000503:physiopathology; D009213:Myography / Q000295:instrumentation / Q000639:trends; D014059:Tongue / Q000502:physiology* / Q000503:physiopathology; D055815:Young Adult
keywords: Amyotrophic lateral sclerosis; Biomarker; Bulbar; Electrical impedance myography; Reliability; Tongue