title: Identification of distinct swallowing patterns for different bolus volumes.
abstract: OBJECTIVE
  To investigate the time interval between glottic closure and the opening of upper esophageal sphincter during swallowing, by means of the coupling of electromyographical (EMG) recordings on the thyroarytenoid (TA) and the cricopharyngeus (CP) muscles.
  
  
  METHODS
  TA-EMG and CP-EMG pause were recorded by concentric needle electrodes using time-locked delay-line circuitry of the EMG apparatus. EMG data obtained from a total of 273 swallows of saliva, 3, 5, 10 and 15 ml volumes of water, were compared.
  
  
  RESULTS
  The relation between the onsets of TA-EMG activity and the CP-EMG pause demonstrated three different patterns of swallows. Pattern A was the delay of the onset of TA-EMG between 50-500 ms, and pattern B was the overlap of its activity with the CP-EMG pause. Pattern C was the earlier occurrence of the TA-EMG 50-550 ms before the CP-EMG pause. Pattern A was the most frequent type of swallows whereas the pattern C appeared during swallowing of larger volumes.
  
  
  CONCLUSIONS
  Physiologically, there is a delay of the TA activation after the onset of CP-EMG pause during swallowing of small amounts in healthy subjects.
  
  
  CONCLUSIONS
  This physiological phenomenon could be a potential risk of aspiration in patients with neurogenic dysphagia.
authors.affiliation: Department of Neurology, Sisli Etfal Education and Research Hospital, Istanbul, Turkey. fmclk@yahoo.com
authors.forename: M Celik
authors.initials: MC
authors.lastname: Gokyigit
authors.forename: N Kuloglu
authors.initials: NK
authors.lastname: Pazarci
authors.forename: I
authors.initials: I
authors.lastname: Ercan
authors.forename: S
authors.initials: S
authors.lastname: Seker
authors.forename: S
authors.initials: S
authors.lastname: Turgut
authors.forename: C
authors.initials: C
authors.lastname: Ertekin
mesh_terms: D000328:Adult; D001193:Arytenoid Cartilage / Q000502:physiology; D003413:Cricoid Cartilage / Q000502:physiology; D003679:Deglutition / Q000502:physiology*; D004558:Electric Stimulation; D004566:Electrodes; D004576:Electromyography; D049631:Esophageal Sphincter, Upper / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000502:physiology