Influence of QPS under AED intake on intracortical inhibition, intracortical facilitation, and plasticity in human

2022 Fiscal Year Final Research Report

• Project/Area Number: 17K09804
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Neurology
• Research Institution: Teikyo Heisei University (2020-2022); Fukushima Medical University (2017-2019)
• Principal Investigator: ENOMOTO Setsu 帝京平成大学, 健康医療スポーツ学部, 教授 (80396374)
• Project Period (FY): 2017-04-01 – 2023-03-31
• Keywords: てんかん / 経頭蓋磁気刺激法

Outline of Final Research Achievements

This study aimed to assess the effect of quadripulse transcranial magnetic stimulation-50 (QPS-50) using a round coil in healthy volunteers. We performed two experiments: the effect in MEP size after a single QPS-50 session with a round coil in nine healthy volunteers, and a follow-up study of motor threshold by repeated QPS-50 sessions administered for 30 min on a weekly basis for 12 weeks in four other healthy participants. The MEP was suppressed significantly after QPS-50 using a round coil. The AMT and RMT gradually decreased bilaterally during the repeated QPS-50 period in all the patients. However, neither AMT nor RMT changed during the entire repeated QPS-50 sessions for a period lasting 13 weeks. In intractable epilepsy patients, administering repeated QPS-50 may paradoxically render the motor cortex more excitable, probably because of abnormal inhibitory control within the epileptic cortex.

Free Research Field

神経内科学

Academic Significance and Societal Importance of the Research Achievements

QPS-50は、健常被験者に対してLTDを誘導する。しかし、先行研究では、ミオクローヌスてんかんや薬剤抵抗性てんかんに対する治療効果を示し得なかった。薬剤抵抗性てんかん患者で、継続的なQPS-50による運動野刺激がAMTを低下させたという事実は、M1の興奮性の増強を示唆している。しかし、本研究で示した通り、健常被験者では運動閾値は変化せず、健常被験者と患者との脳機能の違いを示している。