Analysis of swallowing reflex induced by pharyngeal electrical microstimulation for elderly

• Project/Area Number: 26861849
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Social dentistry
• Research Institution: Fujita Health University
• Principal Investigator: NAKAGAWA Kazuharu 藤田保健衛生大学, 医学部, 助教 (60585719)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2015: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 摂食嚥下障害 / 老年歯科医学 / リハビリテーション医学 / 咽頭微小電気刺激

Outline of Final Research Achievements

Electrical microstimulation of glossopharyngeal and superior laryngeal nerves induce swallowing in rats. Based on this, the purpose of this study was to determine whether pharyngeal electrical microstimulation (PEMS) induced a desire to swallow in humans, and whether age affected the intensity of stimulation to elicit this response.
Subjects were young adult men and elderly. The intensity of stimulation was increased from 0.2 to 2.5 mA until subjects wanted to swallow, which intensity was defined as the desired swallowing threshold (Dsw-Th [mA]). Moreover, we defined the stimulation intensity which was detected by subjects as the perception threshold (Pe-Th [mA]).
Pe-Th was recognized by all subjects and was not influenced by age. At 15 Hz, Dsw-Th was significantly higher in elderly group (1.72±0.2 mA) than young group (1.13±0.3 mA).PEMS could induce desired swallowing in healthy young adults, but the stimulation intensity to induce desired swallowing increased with age.

Research Products

• [Journal Article] Effects of gum chewing exercises on saliva secretion and occlusal force in community-dwelling elderly individuals: A pilot study. (2015)
  • Author(s): Nakagawa K, Matsuo K, Takagi D, Morita Y, Ooka T, Hironaka S, Mukai Y
  • Journal Title: Geriatr Gerontol Int. Volume: 21 Issue: 1 Pages: 1-6
  • DOI: 10.1111/ggi.12670
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] A case in palliative care unit who showed improvement of nutrition by wearing dentures. (2015)
  • Author(s): Nakagawa K, Matsuo K, Taniguchi H, Murai M, Mori N, Higashiguchi T
  • Organizer: The 16th PENSA Congress
  • Place of Presentation: Nagoya, Japan
  • Year and Date: 2015-07-24
• [Presentation] Swallowing Reflex Induced by Electrical Microstimulation of the Pharynx - Comparison by age - (2014)
  • Author(s): Nakagawa K, Watanabe M, Hironaka S, Matsuo K
  • Organizer: ESSD 4th Congress
  • Place of Presentation: Brussels, Belgium, Brussels 44 Center
  • Year and Date: 2014-10-23 – 2014-10-25
• [Presentation] Effects of Viscosity on Swallow Initiation and Breathing-Swallow Pattern during Eating of Two-phase Food In Frail Elderly Individuals (2014)
  • Author(s): Matsuo K, Yamada T, Izawa M, Yamada S, Fujii W, Kanamori D, Nakagawa K, Sumi Y, Ogasawara T
  • Organizer: ESSD 4th Congress
  • Place of Presentation: Brussels, Belgium, Brussels 44 Center
  • Year and Date: 2014-10-23 – 2014-10-25