Motion restored to the paralyzed larynx with implantable stimulator

• Project/Area Number: 26861354
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Otorhinolaryngology
• Research Institution: Asahikawa Medical College
• Principal Investigator: NOMURA Kenichiro 旭川医科大学, 医学部, 助教 (00466484)
• Research Collaborator: KATADA Akihiro
• Project Period (FY): 2014-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000); Fiscal Year 2017: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2016: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2015: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2014: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
• Keywords: 喉頭麻痺 / 機能的電気刺激

Outline of Final Research Achievements

The aim of this study was to create a suitable electrode, and to examine the feasibility of unilateral stimulation to produce vocal fold adduction in unilateral paralyzed larynx. Four canines were used in this study, and divided into denervated group and reinnervated group by recurrent laryngeal nerve (RLN) section or neurorrhaphy. An electrode array consisted of 8 disk electrodes, mounted on a silicone plate. This electrode array was implanted to stimulate thyroarytenoid (TA) muscle. In denervated group TA stimulation could produce nominal glottal closure with high current. On the other hand, in reinnervated group TA stimulation could produce optimal glottal closure with low current. This study demonstrated that TA stimulation with new created electrode could produce optimal glottal closure. However, reinnervation was desired for optimal glottal closure.

Academic Significance and Societal Importance of the Research Achievements

喉頭は呼吸、発声、嚥下、気道防御と多彩な機能に関与する重要な臓器である。喉頭運動を制御する内喉頭筋は、迷走神経から分枝する反回神経の支配を受けている。反回神経が悪性腫瘍や外科手術等によって損傷されると声門の開大や閉鎖が起こらない喉頭麻痺の状態となり、喉頭の機能は著しく障害される。反回神経は末梢神経であり神経吻合により比較的容易に再生するが、再生の段階では本来の選択的な筋支配が失われた過誤支配が起こり、呼吸や発声に同期した合目的な喉頭運動は回復しない。一側性の麻痺では、発声時に声帯が完全に閉鎖しないことによる発声障害が問題となる。電気刺激を用いた治療によりこの発声障害を改善される可能性がある。

Research Products

• [Presentation] 機能的電気刺激による声門閉鎖運動の誘発 (2017)
  • Author(s): 片田彰博, 野村研一郎, 原渕保明
  • Organizer: 第62回日本音声言語医学会
• [Presentation] Electrical stimulation with an implanted device for vocal fold adduction in unilateral paralyzed larynx. (2014)
  • Author(s): Nomura K, Katada A, Kunibe I, Harabuchi Y
  • Organizer: . The 18th Joint meeting of the World Association fot Bronchology and Interventional Pulmonology & The International Bronchoesophagology Society (18th WCBIP/WCBE)
  • Place of Presentation: Kyoto,Japan
  • Year and Date: 2014-04-13 – 2014-04-16