【作者】 谢楚海；

【导师】 孔抗美；

【作者基本信息】 汕头大学 ， 病理与病理生理学， 2008， 博士

【摘要】 背景:功能核磁共振成像能显示人体的生理及病理过程,提供动态和功能方面的信息。脊髓功能核磁共振(Spinal fMRI)能无创伤性地对脊髓神经元活动进行较准确的定位和分析,近几年来已经成为国内外神经科学研究者在脊髓生理和病理研究领域的一种全新研究手段。用功能性核磁共振探讨脊髓病理生理是一个新兴的研究领域,目前国际上的相关研究甚少,利用fMRI研究脊髓损伤尚处于起步阶段,探讨功能核磁共振技术在脊髓损伤方面的应用将有助于脊髓损伤的基础研究和临床。目前fMRI技术主要通过运动、感觉、电流、针灸等刺激方式进行脊髓功能成像。国内外未见应用复杂对指运动及功能性电刺激方式的脊髓功能核磁共振研究。复杂规律的对指运动能产生广泛的大脑皮层兴奋区,常被选为评估人脑功能状况的可行性刺激模式并在脑功能成像中应用,推断该刺激模式也应该在脊髓中产生明显的激活区,能成为评估脊髓功能状况的理想刺激模式。功能性电刺激技术在康复和疾病治疗中有广泛的临床应用价值,研究功能性电刺激下脊髓功能核磁共振的特异性反应,能为理解和发展电刺激治疗脊髓疾病的方法提供依据和方向。在此背景下本课题将首次应用复杂对指运动及功能性电刺激模式进行脊髓功能核磁共振研究。目的:观察复杂对指运动和功能性电刺激时,正常颈脊髓功能核磁共振信号的产生和变化,以及颈脊髓损伤患者脊髓神经功能激活区域的分布与解剖的关系,探讨正常与受损的颈脊髓中神经信号的变化。方法:11名健康志愿者按要求进行复杂对指运动与功能性电刺激,6名颈脊髓损伤的受试患者进行功能性电刺激,采用“静息-任务刺激-静息”的时段设计模式,共4次刺激,5次静息,各长35s。同时用单次激发快速自旋回波序列(SSFSE)的1.5 T核磁共振机采集C2～T2节段横断面及矢状位的fMRI信号。获得的fMRI信号用AFNI软件进行后处理,得到激活信号与解剖信号的叠加图、激活信号值曲线。所得fMRI信号变化值进行统计学分析。结果:单次激发快速自旋回波序列脊髓功能核磁共振技术能检测到不同刺激模式下正常志愿者和颈脊髓损伤患者脊髓功能变化的信号。正常志愿者复杂对指运动和功能性电刺激时脊髓激活信号与相应脊髓节段(C6～T1)运动神经元所在的解剖区域(脊髓腹侧)相符合。fMRI信号变化波动于4.2%～13.2%之间。刺激与静息时相的信号变化幅度有显著差异。部分激活信号出现于脊髓背侧,个别激活信号出现于对侧脊髓和脊髓周围脑脊液中。4名完成实验的患者颈脊髓均出现稳定的fMRI信号,脊髓激活信号以刺激同侧脊髓背角感觉神经元区域为主。刺激对侧脊髓的激活信号强度较弱,对侧脊髓的刺激信号主要位于背角和中间带。结论:利用单次激发快速自旋回波序列脊髓功能核磁共振技术能检测到复杂对指运动和功能性电刺激时正常脊髓功能变化的信号,所得信号与相应的解剖位置相符合。使用1.5T医用核磁共振机和常规颈线圈对脊髓损伤患者的脊髓功能核磁共振成像能检测到受损脊髓的神经信号,有助于评估脊髓功能状况。更多还原

【Abstract】 Backgroud:Spinal fMRI is a reliable tool for assessing neuron status and localizing activity in the spinal cord. In healthy volunteers the method has proved capable of demonstrating spinal cord neuronal activity in response to different stimulations. Finger tapping is a well-established stimulation task for mapping neuronal function in the human brain. Electrical stimulation is widely used as a diagnostic method in spinal cord diseases and has a long history as a rehabilitation tool for restoring mobility after spinal cord injury. The present investigation is to determine if spinal cord neuronal activation while undergoing a complex finger tapping task and electrical stimulation can be observed by spinal fMRI with a SSFSE sequence. Standard assessment of the condition of the spinal cord after an injury, or when affected by disease, is limited to the information that can be revealed by external signs. Information about the full extent of the cord’s condition, and any changes as a result of clinical interventions, is becoming increasingly valuable as treating spinal cord injury (SCI) patients. The purpose of the work we are carrying out is to apply the noninvasive method of fMRI in the injured spinal cord.Purpose: Functional MR imaging of the human spinal cord was carried out on volunteers with complex finger tapping task and functional electrical stimulation, in order to detect image intensity changes arising from neuronal activity. Spinal fMRI was also applied in central cord syndrome patients to investigate the neuronal activity in the cervical spinal cord caudal and to develop spinal fMRI as a clinical diagnostic tool.Methods: Functional MR imaging data using single-shot fast spin-echo sequence (SSFSE) with echo time 42.4ms on a 1.5 T GE Clinical System were acquired in eleven healthy subjects performing complex finger tapping task and functional electrical stimulation. Investigation was also carried out in six patients with cervical spinal cord injury (central cord syndrome). Spinal cord activation was measured both in the sagittal and transverse imaging planes. Postprocessing was performed by AFNI (Analysis of Functional Neuroimages) software system.Results: Intensity changes (4.2%~13.2%) correlated with the time course of stimulation and were consistently detected in both sagittal and transverse imaging planes of the healthy spinal cord. The activated regions localized to the ipsilateral side of the spinal cord in agreement with the neural anatomy. Spinal cord activity was detected with Spinal fMRI in the spinal cord region, below the site of injury, in four spinal cord-injured subjects studied. In subjects with central cord syndrome, activity was consistently observed in the ipsilateral dorsal horn, corresponding to sensory input. Activity was also detected on the contralateral side of the cord and within the anterior median fissure, but was less prominent.Conclusion: Functional MR imaging signals can be reliably detected with finger tapping activity in the human spinal cord using SSFSE sequence. The anatomic location of neural activity correlates with the muscles used in the finger tapping task. We present the first application of Spinal fMRI to spinal cord-injured subjects and the first noninvasive demonstration of activity in the human spinal cord below the site of injury.更多还原