School of Translational Medicine - Inflammation Sciences, University of Manchester (part of the Manchester Academic Health Sciences Centre), Salford Royal Hospital, Salford, England.
Gastroenterology. 2012 Jan;142(1):29-38. doi: 10.1053/j.gastro.2011.09.040. Epub 2011 Sep 29.
BACKGROUND & AIMS: Patients with stroke experience swallowing problems (dysphagia); increased risk of aspiration pneumonia, malnutrition, and dehydration; and have increased mortality. We investigated the behavioral and neurophysiological effects of a new neurostimulation technique (paired associative stimulation [PAS]), applied to the pharyngeal motor cortex, on swallowing function in healthy individuals and patients with dysphagia from stroke.
We examined the optimal parameters of PAS to promote plasticity by combining peripheral pharyngeal (electrical) with cortical stimulation. A virtual lesion was used as an experimental model of stroke, created with 1-Hz repetitive transcranial magnetic stimulation over the pharyngeal cortex in 12 healthy individuals. We tested whether hemispheric targeting of PAS altered swallowing performance before applying the technique to 6 patients with severe, chronic dysphagia from stroke (mean of 38.8 ± 24.4 weeks poststroke).
Ten minutes of PAS to the unlesioned pharyngeal cortex reversed (bilaterally) the cortical suppression induced by virtual lesion (lesioned: F(1,9) = 21.347, P = .001; contralesional: F(1,9) = 9.648, P = .013; repeated-measures analysis of variance) compared with sham PAS. It promoted changes in behavior responses measured with a swallowing reaction time task (F(1,7) = 21.02, P = .003; repeated-measures analysis of variance). In patients with chronic dysphagia, real PAS induced short-term bilateral changes in the brain; the unaffected pharyngeal cortex had increased excitability (P = .001; 95% confidence interval, 0.21-0.05; post hoc paired t test) with reduced penetration-aspiration scores and changes in swallowing biomechanics determined by videofluoroscopy.
The beneficial neurophysiological and behavioral properties of PAS, when applied to unlesioned brain, provide the foundation for further investigation into the use of neurostimulation as a rehabilitative approach for patients with dysphagia from stroke.
脑卒中患者存在吞咽问题（吞咽困难）；有发生吸入性肺炎、营养不良和脱水的风险增加；死亡率也升高。我们研究了一种新的神经刺激技术（配对联想刺激 [PAS]）应用于咽运动皮层对健康个体和脑卒中后吞咽困难患者的吞咽功能的行为和神经生理影响。
我们通过结合外周咽（电）刺激和皮层刺激来检查促进可塑性的 PAS 的最佳参数。使用 1 Hz 重复经颅磁刺激对咽皮层进行 1 次，创建了虚拟病变，作为脑卒中的实验模型。我们在 12 名健康个体中测试了 PAS 的半球靶向是否改变了吞咽性能，然后将该技术应用于 6 名严重、慢性脑卒中后吞咽困难的患者（脑卒中后平均 38.8 ± 24.4 周）。
10 分钟的 PAS 作用于未损伤的咽皮层，逆转了虚拟病变引起的皮层抑制（患侧：F(1,9) = 21.347，P =.001；对侧：F(1,9) = 9.648，P =.013；重复测量方差分析）与假 PAS 相比。它促进了吞咽反应时间任务测量的行为反应变化（F(1,7) = 21.02，P =.003；重复测量方差分析）。在慢性吞咽困难患者中，真实的 PAS 诱导了未受影响的咽皮层的短期双侧变化；未受影响的咽皮层兴奋性增加（P =.001；95%置信区间，0.21-0.05；事后配对 t 检验），穿透性吸入评分降低，视频荧光透视检查确定的吞咽生物力学发生变化。
PAS 的有益神经生理和行为特性，当应用于未受损的大脑时，为进一步研究神经刺激作为脑卒中后吞咽困难患者的康复方法提供了基础。
