Gastrointestinal Physiology Laboratory, Department of Surgery, Hospital de Mataró (Universitat Autónoma de Barcelona), Mataró, Spain.
Centro de Investigación Biomédica en Red de enfermedades hepáticas y digestivas (CIBERehd), Instituto de Salud Carlos III, Madrid, Spain.
Neurogastroenterol Motil. 2020 Sep;32(9):e13887. doi: 10.1111/nmo.13887. Epub 2020 May 24.
Neurorehabilitation strategies for chronic poststroke (PS) oropharyngeal dysphagia (OD) have been mainly focused on the neurostimulation of the pharyngeal motor cortex with only marginal effects. In contrast, treatments targeting the PS oropharyngeal sensory pathway dysfunction offer very promising results, but there is little knowledge on the underlying mechanisms. We aimed to explore the neurophysiological mechanisms behind the effect of three sensory neurostimulation strategies.
We carried out a randomized two-blinded parallel group's crossover sham-controlled clinical trial in 36 patients with unilateral stroke and chronic unsafe swallow to investigate the effect of repetitive transcranial magnetic stimulation (rTMS) of the primary sensory cortex (A), oral capsaicin (B) and intra-pharyngeal electrical stimulation (IPES; C). The effect was evaluated immediately after the interventions with videofluoroscopy (VFS) and motor/sensory evoked potentials (MEP/SEP).
Interventions induced no changes in the biomechanics of the swallow response during VFS. However, an enhancement of motor cortex excitability (latency shortening and increased size of thenar MEP) was found with active interventions (A + B + C, and B/C alone; P < .05 for all) but not with sham. Active but not sham interventions shortened pharyngeal SEP latency in the ipsilesional hemisphere (A + B + C: P2-peak, P = .039; A: N2-peak, P = .034) and antagonized the physiological habituation in pharyngeal MEP (A + B + C and A alone, P < .05 for both).
Sensory pathway neurostimulation strategies caused immediate enhancement of motor cortex excitability with peripheral strategies (capsaicin and IPES) and of pharyngeal sensory conduction with rTMS. These changes support the use of sensory neurorehabilitation strategies in promoting swallow recovery in chronic PS-OD.
针对慢性卒中后（PS）口咽吞咽困难（OD）的神经康复策略主要集中在对咽运动皮层的神经刺激上，但其效果甚微。相比之下，针对 PS 口咽感觉通路功能障碍的治疗方法提供了非常有前景的结果，但对其潜在机制知之甚少。我们旨在探索三种感觉神经刺激策略背后的神经生理机制。
我们在 36 例单侧卒中后且吞咽不安全的慢性期患者中进行了一项随机、双盲、平行组交叉假对照临床试验，以研究初级感觉皮层重复经颅磁刺激（rTMS）（A）、口腔辣椒素（B）和内咽电刺激（IPES；C）的效果。干预后立即通过视频透视（VFS）和运动/感觉诱发电位（MEP/SEP）进行评估。
干预措施并未改变 VFS 中吞咽反应的生物力学。然而，仅在主动干预（A+B+C 和 B/C 单独）而非假刺激时，发现运动皮层兴奋性增强（潜伏期缩短和鱼际 MEP 增大）（所有 P<.05）。主动干预而非假刺激缩短了同侧半球的咽 SEP 潜伏期（A+B+C：P2-峰值，P=.039；A：N2-峰值，P=.034），并拮抗了咽 MEP 的生理习惯化（A+B+C 和 A 单独，两者均 P<.05）。
感觉通路神经刺激策略通过外周策略（辣椒素和 IPES）引起运动皮层兴奋性的即时增强，通过 rTMS 引起咽感觉传导的即时增强。这些变化支持在慢性 PS-OD 中使用感觉神经康复策略来促进吞咽恢复。
