Gobbelé R, Halboni P, Buchner H, Waberski T D
Department of Neurology, University Hospital Aachen, Pauwelsstr. 30, RWTH, D-52057 Aachen, Germany.
Clin Neurophysiol. 2007 Nov;118(11):2497-505. doi: 10.1016/j.clinph.2007.08.008. Epub 2007 Sep 24.
We investigated the interference of tactile and painful stimuli on human early somatosensory evoked potentials (SEPs) including high frequency oscillations (HFOs) to further study thalamocortical processing of somatosensory information.
Multi-channel median nerve SEPs were recorded during (1) no interference, (2) sensory interference by tactile stimulation to digits 2 and 3, and (3) application of pain to the same digits. Spatio-temporal source analysis separated brain stem (S1), thalamic (S2) and two cortical sources (S3, S4), which were evaluated for the low (20-450 Hz) and high (450-750 Hz) frequency portion of the signal.
Low frequency SEPs showed a decrease of activity at cortical source S3 during both conditions, while thalamic source S2 was significantly increased during pain interference. HFOs showed an increase of cortical source S3 and in trend of thalamic source S2 and cortical source S4 during both kinds of interference.
Although the painful stimulus might not be specific for the nociceptive afferents, the present data affirm that at this early stage of sensory information processing within the primary sensory cortex (area 3b, area 1) pain is handled similar to sensory interference.
HFOs might represent an intrinsic "somatosensory alerting" system which reacts to both interference stimuli in a similar way, therefore indicating an interference without a qualitative evaluation.
我们研究了触觉和痛觉刺激对人类早期体感诱发电位（SEPs）的干扰，包括高频振荡（HFOs），以进一步研究体感信息的丘脑皮质处理过程。
在以下三种情况下记录多通道正中神经SEPs：（1）无干扰；（2）对第2和第3指进行触觉刺激产生感觉干扰；（3）对同一手指施加疼痛刺激。时空源分析分离出脑干（S1）、丘脑（S2）和两个皮质源（S3、S4），并对信号的低频（20 - 450Hz）和高频（450 - 750Hz）部分进行评估。
低频SEPs在两种情况下均显示皮质源S3的活动降低，而在疼痛干扰期间丘脑源S2显著增加。HFOs在两种干扰期间均显示皮质源S3增加，丘脑源S2和皮质源S4有增加趋势。
尽管痛觉刺激可能并非伤害性传入所特有，但目前的数据证实，在初级感觉皮层（3b区、1区）感觉信息处理的这一早期阶段，疼痛的处理方式与感觉干扰相似。
HFOs可能代表一种内在的“体感警报”系统，它以相似的方式对两种干扰刺激做出反应，因此表明存在一种无需定性评估的干扰。
