McKeown Martin J, Torpey Dana C, Gehm Wendy C
Brain Imaging and Analysis Center, 254E Bell Research Building, Box 3918, Duke University Medical Center, Durham, NC 27710, USA.
Clin Neurophysiol. 2002 Mar;113(3):354-66. doi: 10.1016/s1388-2457(02)00007-x.
Dysphagia is an important consequence of many diseases. As some of the muscles of deglutition tend to be deep to the surface, needle electrodes are typically used, but this limits the number of muscles that can be simultaneously recorded. Since control of swallowing involves central pattern generators (CPGs) which distribute commands to several muscles, monitoring several muscles simultaneously is desirable. Here we describe a novel method, based on computing the independent components (ICs) of the simultaneous sEMG recordings (Muscle Nerve Suppl 9 (2000) 9) to detect the underlying functional muscle activations during swallowing using only surface EMG (sEMG) electrodes.
Seven normal subjects repeatedly swallowed liquids of varying consistency while sEMG was recorded from 15 electrodes from the face and throat. Active areas of EMG were excised from the recordings and the ICs of the sEMG were calculated.
The ICs demonstrated less swallow-to-swallow variability than the raw sEMG. The ICs, each consisting of a unique temporal waveform and a spatial distribution, provided a means to segregate the complex sequence of muscle activation into rigorously defined separate functional units. The temporal profiles of the ICs and their spatial distribution were consistent with prior needle EMG studies of the cricopharyngeal, superior pharyngeal constrictor, submental and possibly arytenoid muscles. Other components appeared to correspond to EKG artifact contaminating the EMG recordings, laryngeal excursion, tongue movement and activation of the buccal and/or masseter musculature At least two of the components were affected by the consistency of the liquids swallowed. Re-testing one subject a week later demonstrated good intertrial reliability.
We propose that the ICs of the sEMG provide a non-invasive means to assess the complex muscle sequence activation of deglutition.
吞咽困难是许多疾病的重要后果。由于一些吞咽肌肉往往位于体表深部，通常使用针电极，但这限制了可同时记录的肌肉数量。由于吞咽控制涉及中枢模式发生器（CPG），其将指令分配到多个肌肉，因此同时监测多个肌肉是可取的。在此，我们描述一种基于计算同步表面肌电图（sEMG）记录的独立成分（IC）的新方法（《肌肉与神经增刊9》（2000年）9），以仅使用表面肌电图（sEMG）电极检测吞咽过程中潜在的功能性肌肉激活。
7名正常受试者反复吞咽不同黏稠度的液体，同时从面部和喉咙的15个电极记录sEMG。从记录中切除肌电图的活跃区域，并计算sEMG的IC。
IC显示出比原始sEMG更小的吞咽间变异性。每个IC由独特的时间波形和空间分布组成，提供了一种将复杂的肌肉激活序列分离为严格定义的独立功能单元的方法。IC的时间轮廓及其空间分布与先前对环咽肌、咽上缩肌、颏下肌以及可能的杓状肌的针电极肌电图研究一致。其他成分似乎对应于污染肌电图记录的心电图伪迹、喉部运动、舌头运动以及颊部和/或咬肌的激活。至少有两个成分受吞咽液体黏稠度的影响。一周后对一名受试者进行重新测试显示出良好的试验间可靠性。
我们提出sEMG的IC提供了一种非侵入性手段来评估吞咽时复杂的肌肉序列激活。
