Saitoh Youichi, Osaki Yasuhiro, Nishimura Hiroshi, Hirano Shun-ichiro, Kato Amami, Hashikawa Kazuo, Hatazawa Jun, Yoshimine Toshiki
Department of Neurosurgery, Osaka University Medical School, Suita, Osaka, Japan.
J Neurosurg. 2004 May;100(5):935-9. doi: 10.3171/jns.2004.100.5.0935.
The mechanisms underlying poststroke pain have not been clearly identified. Although motor cortex stimulation (MCS) sometimes reduces poststroke pain successfully, the exact mechanism is not yet known. For further investigation of the neural pathways involved in the processing of poststroke pain and in pain reduction by MCS, the authors used positron emission tomography (PET) scanning to determine significant changes in regional cerebral blood flow (rCBF). This 58-year-old right-handed man suffered from right-sided poststroke pain for which he underwent implantation of a stimulation electrode in the right motor cortex. After 30 minutes of stimulation, his pain was remarkably reduced (Visual Analog Scale scores decreased 8 to 1) and he felt warmth in his left arm. The rCBF was studied using PET scanning with 15O-labeled water when the patient was in the following states: before MCS (painful condition, no stimulation) and after successful MCS (painless condition, no stimulation). The images were analyzed using statistical parametric mapping software. State-dependent differences in global blood flow were covaried using analysis of covariance. Comparisons of the patient's rCBF in the painful condition with that in the painless condition revealed significant rCBF increases in the left rectus gyrus (BA11), left superior frontal lobe (BA9), left anterior cingulate gyms (BA32), and the left thalamus (p < 0.05, corrected). On the other hand, there were significant decreases in rCBF in the right superior temporal gyrus (BA22, p < 0.01, corrected) and the left middle occipital gyrus (BA19, p < 0.05, corrected). The efficacy of MCS was mainly related to increased synaptic activity in the thalamus, whereas the activations in the rectus gyrus, anterior cingulate gyrus, and superior frontal cortex as well as the inactivation of the superior temporal lobe may be related to emotional processes. This is the first report in which the contralateral thalamus was significantly activated and pain relief was achieved using MCS.
中风后疼痛的潜在机制尚未明确。尽管运动皮层刺激(MCS)有时能成功减轻中风后疼痛,但其确切机制尚不清楚。为了进一步研究参与中风后疼痛处理及MCS减轻疼痛过程的神经通路,作者使用正电子发射断层扫描(PET)来确定局部脑血流量(rCBF)的显著变化。这位58岁的右利手男性患有右侧中风后疼痛,为此他在右侧运动皮层植入了刺激电极。刺激30分钟后,他的疼痛明显减轻(视觉模拟评分从8分降至1分),并且他感到左臂发热。当患者处于以下状态时,使用15O标记水的PET扫描研究rCBF:MCS前(疼痛状态,无刺激)和成功的MCS后(无痛状态,无刺激)。使用统计参数映射软件分析图像。使用协方差分析对全局血流的状态依赖性差异进行协变量分析。将患者疼痛状态下的rCBF与无痛状态下的rCBF进行比较,结果显示左侧直回(BA11)、左侧额上回(BA9)、左侧前扣带回(BA32)和左侧丘脑的rCBF显著增加(p<0.05,校正后)。另一方面,右侧颞上回(BA22,p<0.01,校正后)和左侧枕中回(BA19,p<0.05,校正后)的rCBF显著降低。MCS的疗效主要与丘脑中突触活动增加有关,而直回、前扣带回和额上皮质的激活以及颞上叶的失活可能与情绪过程有关。这是首次报告使用MCS使对侧丘脑显著激活并实现疼痛缓解。