title: Pharyngeal electrical stimulation can modulate swallowing in cortical processing and behavior - magnetoencephalographic evidence.
abstract: BACKGROUND
  The act of swallowing is a complex neuromuscular function that is processed in a distributed network involving cortical, subcortical and brainstem structures. Difficulty in swallowing arises from a variety of neurologic diseases for which therapeutic options are currently limited. Pharyngeal electrical stimulation (PES) is a novel intervention designed to promote plastic changes in the pharyngeal motor cortex to aid dysphagia rehabilitation. In the present study we evaluate the effect of PES on cortical swallowing network activity and associated changes in swallowing performance.
  
  
  METHODS
  In a randomized, crossover study design 10min of real (0.2-ms pulses, 5Hz, 280V, stimulation intensity at 75% of maximum tolerated threshold) or sham PES were delivered to 14 healthy volunteers in two separate sessions. Stimulation was delivered via a pair of bipolar ring electrodes mounted on an intraluminal catheter positioned in the pharynx. Before and after each intervention swallowing capacity (ml/s) was tested using a 150ml-water swallowing stress test. Event-related desynchronization (ERD) of cortical oscillatory activity during volitional swallowing was recorded applying whole-head magnetoencephalography before, immediately after and 45min past the intervention.
  
  
  RESULTS
  A prominent reduction of ERD in sensorimotor brain areas occurred in the alpha and beta frequency ranges immediately after real PES but not after sham stimulation (p<0.05) and had faded after 45min. Volume per swallow and swallowing capacity significantly increased following real stimulation only.
  
  
  CONCLUSIONS
  Attenuation of ERD following PES reflects stimulation-induced increased swallowing processing efficiency, which is associated with subtle changes in swallowing function in healthy subjects. Our data contribute evidence that swallowing network organization and behavior can effectively be modulated by PES.
authors.affiliation: Department of Neurology, University of Muenster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149 Münster, Germany; Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Malmedyweg 15, 48149 Muenster, Germany. Electronic address: sonjasuntrup@uni-muenster.de.
authors.forename: Sonja
authors.initials: S
authors.lastname: Suntrup
authors.affiliation: Department of Neurology, University of Muenster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149 Münster, Germany.
authors.forename: Inga
authors.initials: I
authors.lastname: Teismann
authors.affiliation: Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Malmedyweg 15, 48149 Muenster, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Wollbrink
authors.affiliation: Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Malmedyweg 15, 48149 Muenster, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Winkels
authors.affiliation: Department of Neurology, University of Muenster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149 Münster, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Warnecke
authors.affiliation: Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Malmedyweg 15, 48149 Muenster, Germany.
authors.forename: Christo
authors.initials: C
authors.lastname: Pantev
authors.affiliation: Department of Neurology, University of Muenster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149 Münster, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Dziewas
mesh_terms: D000328:Adult; D001519:Behavior / Q000502:physiology*; D018592:Cross-Over Studies; D003679:Deglutition / Q000502:physiology*; D004558:Electric Stimulation; D004576:Electromyography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015225:Magnetoencephalography; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D010614:Pharynx / Q000502:physiology*