title: Exploring the effects of synchronous pharyngeal electrical stimulation with swallowing carbonated water on cortical excitability in the human pharyngeal motor system.
abstract: BACKGROUND
  Previous reports have revealed that excitation of human pharyngeal motor cortex can be induced by pharyngeal electrical stimulation (PES) and swallowing carbonated water (CW). This study investigated whether combining PES with swallowing (of still water, SW or CW) can potentiate this excitation in either cortical and/or brain stem areas assessed with transcranial and transcutaneous magnetic stimulation (TMS).
  
  
  METHODS
  Fourteen healthy volunteers participated and were intubated with an intraluminal catheter to record pharyngeal electromyography and deliver PES. Each participant underwent baseline corticopharyngeal, hand and craniobulbar motor-evoked potential (MEP) measurements. Subjects were then randomized to receive each of four 10-min interventions (PES only, ShamPES+CW, PES+CW, and PES+SW). Corticobulbar, craniobulbar and hand MEPs were then remeasured for up to 60 min and data analyzed using anova and post hoc t-tests.
  
  
  RESULTS
  A two-way rmanova for Interventions × Time-point showed a significant corticopharyngeal interaction (p = 0.010). One-way anova with post hoc t-tests indicated significant cortical changes with PES only at 45 (p = 0.038) and 60 min (p = 0.023) and ShamPES+CW immediately (p = 0.008) but not with PES+CW or PES+SW. By contrast, there were immediate craniobulbar amplitude changes only with PES+CW (p = 0.020) which were not sustained.
  
  
  CONCLUSIONS
  We conclude that only PES produced long-term changes in corticopharyngeal excitability whereas combination stimuli were less effective. Our data suggest that PES alone rather than in combination, may be better for the patients who have difficulty in performing voluntary swallows.
authors.affiliation: Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.|Centre for Gastrointestinal Sciences, Institute of Inflammation and Repair, Faculty of Medical and Human Sciences, University of Manchester, Salford, UK.
authors.forename: J
authors.initials: J
authors.lastname: Magara
authors.affiliation: Centre for Gastrointestinal Sciences, Institute of Inflammation and Repair, Faculty of Medical and Human Sciences, University of Manchester, Salford, UK.
authors.forename: E
authors.initials: E
authors.lastname: Michou
authors.affiliation: Centre for Gastrointestinal Sciences, Institute of Inflammation and Repair, Faculty of Medical and Human Sciences, University of Manchester, Salford, UK.
authors.forename: A
authors.initials: A
authors.lastname: Raginis-Zborowska
authors.affiliation: Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Inoue
authors.affiliation: Centre for Gastrointestinal Sciences, Institute of Inflammation and Repair, Faculty of Medical and Human Sciences, University of Manchester, Salford, UK.
authors.forename: S
authors.initials: S
authors.lastname: Hamdy
mesh_terms: D000328:Adult; D001933:Brain Stem / Q000502:physiology*; D061545:Carbonated Water; D003679:Deglutition / Q000502:physiology*; D004558:Electric Stimulation; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D010614:Pharynx / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
chemical_list: D061545:Carbonated Water
keywords: carbonated water; neurorehabilitation; pharyngeal electrical stimulation; transcranial magnetic stimulation