Wang K, Sessle B J, Svensson P, Arendt-Nielsen L
Center for Sensory-Motor Interaction, Orofacial Pain Laboratory, Aalborg University, Fredrik Bajers Vej 7 D-3, DK-9220 Aalborg E, Denmark.
Clin Neurophysiol. 2004 Jun;115(6):1288-95. doi: 10.1016/j.clinph.2004.01.006.
Although pain and neuromuscular function are clearly linked in several clinical conditions manifested in the craniofacial and cervical regions, it is unclear if pain in these regions influences reflexly evoked activity in the jaw or neck muscles in humans. The aim of the present study was to test the effects of glutamate-evoked jaw or neck muscle pain on the jaw stretch reflex recorded in both jaw and neck muscles.
Nineteen healthy men participated in the study. Electromyographic (EMG) recordings were made from the left masseter (MAL) and right masseter (MAR) muscles and the right sternocleidomastoid (SCM) and splenius (SP) muscles. Glutamate (1 M) or isotonic saline was injected into the MAR or right SP in random order and then the other solution was injected 1-3 weeks later. Pain intensity was scored on a 10 cm visual analogue scale. Stretch reflexes were evoked by standardized jaw stretches before, during and 15 min after the end of the experimental muscle pain. Twenty trials were averaged in each condition.
Pain evoked by MAR or SP glutamate injections was associated with a significant increase in the stretch reflex amplitude recorded in both MAR and SCM. The onset and offset times and duration of the stretch reflex did not change in any muscle during the various pain conditions. Injection of isotonic saline into the MAR or SP did not produce any significant change in the reflex parameters in any of the muscles.
The results indicate the close interplay between the craniofacial and cervical regions in the neuromuscular changes that may result from musculoskeletal pain in either region.
The changes in neuromuscular activity documented in this study may be involved in the clinical occurrence of altered muscle activity in the orofacial and cervical regions as a result of deep tissue trauma and pain.
尽管在颅面和颈部出现的多种临床病症中，疼痛与神经肌肉功能之间存在明显关联，但尚不清楚这些区域的疼痛是否会反射性地影响人类下颌或颈部肌肉的诱发活动。本研究的目的是测试谷氨酸诱发的下颌或颈部肌肉疼痛对下颌和颈部肌肉中记录的下颌牵张反射的影响。
19名健康男性参与了该研究。从左侧咬肌（MAL）、右侧咬肌（MAR）、右侧胸锁乳突肌（SCM）和斜方肌（SP）进行肌电图（EMG）记录。将谷氨酸（1 M）或等渗盐水随机注射到MAR或右侧SP中，1至3周后再注射另一种溶液。疼痛强度用10厘米视觉模拟量表评分。在实验性肌肉疼痛结束前、期间和结束后15分钟，通过标准化的下颌伸展诱发牵张反射。每种情况下平均进行20次试验。
MAR或SP注射谷氨酸诱发的疼痛与MAR和SCM中记录的牵张反射幅度显著增加相关。在各种疼痛情况下，任何肌肉中牵张反射的起始和偏移时间以及持续时间均未改变。向MAR或SP注射等渗盐水在任何肌肉的反射参数中均未产生任何显著变化。
结果表明，颅面和颈部区域在神经肌肉变化方面密切相互作用，这种变化可能由任一区域的肌肉骨骼疼痛引起。
本研究记录的神经肌肉活动变化可能与深部组织创伤和疼痛导致的口面部和颈部区域肌肉活动改变的临床发生有关。
