Sleep Disorders Program, Division of Sleep Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, USA.
Am J Respir Crit Care Med. 2012 Feb 1;185(3):322-9. doi: 10.1164/rccm.201106-1058OC. Epub 2011 Oct 20.
Controversy persists regarding the presence and importance of hypoglossal nerve dysfunction in obstructive sleep apnea (OSA).
We assessed quantitative parameters related to motor unit potential (MUP) morphology derived from electromyographic (EMG) signals in patients with OSA versus control subjects and hypothesized that signs of neurogenic remodeling would be present in the patients with OSA.
Participants underwent diagnostic sleep studies to obtain apnea-hypopnea indices. Muscle activity was detected with 50-mm concentric needle electrodes. The concentric needle was positioned at more than 10 independent sites per subject, after the local anatomy of the upper airway musculature was examined by ultrasonography. All activity was quantified with subjects awake, during supine eupneic breathing while wearing a nasal mask connected to a pneumotachograph. Genioglossus EMG signals were analyzed offline by automated software (DQEMG), which extracted motor unit potential trains (MUPTs) contributed by individual motor units from the composite EMG signals. Quantitative measurements of MUP templates, including duration, peak-to-peak amplitude, area, area-to-amplitude ratio, and size index, were compared between the untreated patients with OSA and healthy control subjects.
A total of 1,655 MUPTs from patients with OSA (n = 17; AHI, 55 ± 6/h) and control subjects (n = 14; AHI, 4 ± 1/h) were extracted from the genioglossus muscle EMG signals. MUP peak-to-peak amplitudes in the patients with OSA were not different compared with the control subjects (397.5 ± 9.0 vs. 382.5 ± 10.0 μV). However, the MUPs of the patients with OSA were longer in duration (11.5 ± 0.1 vs. 10.3 ± 0.1 ms; P < 0.001) and had a larger size index (4.09 ± 0.02 vs. 3.92 ± 0.02; P < 0.001) compared with control subjects.
These results confirm and quantify the extent and existence of structural neural remodeling in OSA.
关于阻塞性睡眠呼吸暂停（OSA）患者舌下神经功能障碍的存在和重要性仍存在争议。
我们评估了从肌电图（EMG）信号中获得的与运动单位电位（MUP）形态相关的定量参数，比较了 OSA 患者与对照组之间的差异，并假设 OSA 患者会出现神经重塑的迹象。
参与者接受诊断性睡眠研究以获得呼吸暂停低通气指数。使用 50mm 同心针电极检测肌肉活动。在通过超声检查检查上气道肌肉解剖结构后，将同心针放置在每个受试者 10 个以上的独立部位。在受试者清醒时、佩戴连接到气动计的鼻罩进行仰卧位呼吸时、进行定量分析。使用自动软件（DQEMG）对颏舌肌 EMG 信号进行离线分析，该软件从复合 EMG 信号中提取由单个运动单位贡献的运动单位电位（MUPT）。比较未经治疗的 OSA 患者和健康对照组之间 MUP 模板的定量测量值，包括持续时间、峰峰值幅度、面积、面积-幅度比和大小指数。
从 OSA 患者（n=17；AHI，55±6/h）和对照组（n=14；AHI，4±1/h）的颏舌肌 EMG 信号中提取了 1655 个 MUPT。与对照组相比，OSA 患者的 MUP 峰峰值幅度没有差异（397.5±9.0 vs.382.5±10.0μV）。然而，与对照组相比，OSA 患者的 MUP 持续时间更长（11.5±0.1 vs.10.3±0.1ms；P<0.001），且大小指数更大（4.09±0.02 vs.3.92±0.02；P<0.001）。
这些结果证实并量化了 OSA 中结构神经重塑的程度和存在。
