title: Effect of transcutaneous electrical stimulation amplitude on timing of swallow pressure peaks between healthy young and older adults.
abstract: OBJECTIVE
  This study compared the effect of transcutaneous electrical stimulation (TES) amplitude on timing of lingual-palatal and pharyngeal peak pressures during swallowing in healthy younger and older adults.
  
  
  BACKGROUND
  Transcutaneous electrical stimulation amplitude is one parameter that may have different impacts on the neuromotor system and swallowing physiology. One aspect of swallowing physiology influenced by age is the timing of swallowing events. However, the effect of varying TES amplitudes on timing of swallowing physiology is poorly understood, especially in older adults.
  
  
  METHODS
  Thirty-four adults (20 younger and 14 older) swallowed 10 ml of nectar-thick liquid under three TES conditions: no stimulation, low-amplitude stimulation and high-amplitude stimulation. TES was delivered by surface electrodes on the anterior neck. Timing of pressure peaks for lingual-palatal contacts and pharyngeal pressures were measured under each condition.
  
  
  RESULTS
  A significant age × stimulation amplitude interaction was identified for the base of tongue (BOT) [F(2,62) = 5.087, p < 0.009] and the hypopharynx (HYPO) [F(2,62) = 3.277, p < 0.044]. At the BOT, low-amplitude TES resulted in slower swallows in the younger adults compared with no TES. In older adults, low-amplitude TES resulted in faster swallows compared with high-amplitude TES. At the HYPO, no significant differences were identified in pressure timing across the three TES amplitudes in both age groups. In each case, low-amplitude TES resulted in faster swallows in older adults compared with younger adults.
  
  
  CONCLUSIONS
  Transcutaneous electrical stimulation influences pharyngeal pressure timing differently in young and old people, which questions the appropriateness of using a 'one-size-fits-all' TES amplitude for rehabilitating people with dysphagia.
authors.affiliation: Department of Speech, Language and Hearing Sciences, University of Florida, Gainesville, FL, USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Barikroo
authors.affiliation: Speech Pathology/Audiology Department, Bauru Dental School, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Giedré
authors.initials: G
authors.lastname: Berretin-Felix
authors.affiliation: Swallowing Research Laboratory, Department of Communication Sciences and Disorders, University of Central Florida, Orlando, FL, USA.
authors.forename: Giselle
authors.initials: G
authors.lastname: Carnaby
authors.affiliation: Swallowing Research Laboratory, Department of Communication Sciences and Disorders, University of Central Florida, Orlando, FL, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Crary
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D003679:Deglutition / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010159:Palate / Q000502:physiology; D010609:Pharyngeal Muscles / Q000502:physiology; D014059:Tongue / Q000502:physiology; D004561:Transcutaneous Electric Nerve Stimulation; D055815:Young Adult
keywords: age; pressure timing; swallowing; transcutaneous electrical stimulation amplitude