Institute of Respiratory Disease, The 1st Affiliated Hospital of China Medical University, Shen Yang City, Liao Ning Province, China.
Respirology. 2010 Nov;15(8):1209-14. doi: 10.1111/j.1440-1843.2010.01858.x.
During wakefulness, the electromyography (EMG) activities of upper airway dilator muscles are higher in OSA syndrome (OSAS) patients than those in normal subjects. This is believed to be related to central compensatory mechanisms. This study aimed to assess the central motor conductivity of genioglossus (GG) during wakefulness and to evaluate the compensatory site in OSAS patients.
Twelve OSAS patients and 12 normal subjects were recruited to record motor evoked potential (MEP) of GG to transcranial magnetic stimulation applied at dominant-sided anterolateral area and GG response to magnetic stimulation at the third cervical level. Stimuli were delivered at the end of expiration and inspiration respectively. The central motor conduction time (CMCT) was calculated by the latency difference between cortical and cervical stimulations.
The MEP latency and CMCT of GG in OSAS patients were shorter than those in normal subjects at the end of expiration (MEP latency: 6.08 ± 2.06 ms and 8.24 ± 2.66 ms, respectively, P < 0.05; CMCT: 2.41 ± 1.20 ms and 3.58 ± 1.53 ms, respectively, P < 0.05). However, only in normal subjects, GG MEP latency and CMCT showed significant decrease from the end of expiration to the end of inspiration. GG CMCT of OSAS patients at the end of expiration was closely correlated with AHI (r = -0.797, P = 0.002), the nadir oxygen saturation (r = 0.76, P = 0.003) and the longest apnoea time (r = -0.68, P = 0.02).
OSAS patients have an increased central motor conductivity of GG than normal subjects. Furthermore, this increased central motor conductivity of GG is related to the severity of OSAS.
在觉醒状态下，阻塞性睡眠呼吸暂停综合征（OSAS）患者上气道扩张肌的肌电图（EMG）活动高于正常受试者。这被认为与中枢补偿机制有关。本研究旨在评估觉醒状态下颏舌肌（GG）的中枢运动传导，并评估 OSAS 患者的代偿部位。
招募 12 例 OSAS 患者和 12 例正常对照者，记录经颅磁刺激对优势侧前外侧区和 GG 磁刺激时 GG 的运动诱发电位（MEP），刺激分别在呼气末和吸气末进行。通过皮质和颈刺激之间的潜伏期差计算中枢运动传导时间（CMCT）。
在呼气末，OSAS 患者的 GG MEP 潜伏期和 CMCT 短于正常对照组（MEP 潜伏期：分别为 6.08 ± 2.06 ms 和 8.24 ± 2.66 ms，P < 0.05；CMCT：分别为 2.41 ± 1.20 ms 和 3.58 ± 1.53 ms，P < 0.05）。然而，只有在正常对照组中，GG 的 MEP 潜伏期和 CMCT 从呼气末到吸气末显著降低。OSAS 患者呼气末的 GG CMCT 与 AHI（r = -0.797，P = 0.002）、最低血氧饱和度（r = 0.76，P = 0.003）和最长呼吸暂停时间（r = -0.68，P = 0.02）密切相关。
OSAS 患者的 GG 中枢运动传导高于正常对照组。此外，这种 GG 中枢运动传导的增加与 OSAS 的严重程度有关。
