秋千诱发运动病自发脑电的变化

EEG Changes in Man during Motion Sickness Induced by Parallel Swing

本文对11名健康男性青年(19—24岁)秋千诱发运动病过程中自发脑电连续记录并进行了功率谱分析。结果表明:出现运动病症状后,11名被试者脑电图都有显著改变。其中8人以脑前部(额、中央)θ频段(4.0～7.75Hz)的积分值显著上升为主,并且其变化与运动病症状得分(SS)有一致性趋势,但其α频段(8.0～11.75Hz)积分值没有显著性下降。这8人中有5人出现了θ节律性爆发;另外3人则以脑后部(枕、顶)α频段的显著下降为主,其变化与SS值没有明显的一致性,θ频段没有显著性改变。脑电θ及α节律的变化在一定程度上可反映运动病症状的程度。脑电图的上述变化结合运动病时出现的困倦、四肢无力等症状可以推测,运动病发生时大脑网状结构和皮层的兴奋性受到了一定程度的抑制。

Signs and hymptoms of disturbances of autonomic nervous system such as sweating, pallor, flusing, vomiting,or nausea often occured during motion sickness (MS). They are usually reflected in the disorders of brain electroactivity, such as decrease of a activity and increase of θ activity. So the EEG recorded could be expected to provide some information about the brain functions of man during MS and to serve as an indicator of severity of MS.In this study, MS was induced by parallel swing with 6 meters long arms and about 0.2 Hz swing frequency. Eyes of subjects were closed during the experiment. 8 bipolar channels of EEG,Fpl—F3—C3—P3—01 and Fp2—F4—C4—P4—02, of 11 young, healthy, male volunteers were recorded continuously with the Medilog—9000 recorder pre-, during and post swing. SS, the value of MS severity, was evaluated by the criteria postulated by Graybel. Different to the former studies with rotating chair experiment in which only the increase of θ band spectra of EEG was reported, 2 types of EEG changes were observed. In 8 of 11 subjects, changes were mainly increase of power in θ band (4.0 to 7.75 Hz) in frontal and center area without increase of power in α band (8.0 to 11.75 Hz), and 5 of those 8 subjects had θ rhythmic discharges; while power of a band in the other 3 of those 11 subjects (parietal and occipital) decreased significantly without increase of power in θ band It's reasonable to postulate that responses of EEG to stimulation might be different because the clinical signs were different among the subjects during MS. The θ band of EEG changed in a similar trend as the SS did. It was suggested that the EEG could serve as an indicator of severity of MS in some degree. The decrease of α, the increase of θ activities and the autonomic nervous dysfunctions of the subjects indicated the reduction of reticular and cerebral cortical activities of brain during MS.