Cortical processing of noxious somatosensory stimuli in the persistent vegetative state
Cortical processing of noxious somatosensory stimuli in the persistent vegetative state
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DOI：
10.1006/nimg.2002.1236
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发表时间：
2002-10-01
期刊：
影响因子：
5.7
通讯作者：
Maquet, P
中科院分区：
文献类型：
--
作者：
Laureys, S;Faymonville, ME;Maquet, P
持续植物状态（PVS）是一种毁灭性的疾病，其特征是保持清醒，而缺乏与环境的自愿互动。我们使用正电子发射断层扫描来评估PVS中伤害性躯体感觉刺激的中枢处理。在15名未服用镇静剂的患者和15名健康对照者中，测量了正中神经高强度电刺激期间与休息时局部脑血流的变化。同时记录诱发电位。在对照组中，刺激被体验为高度不愉快至疼痛。在静息条件下，还用[F-18]氟脱氧葡萄糖研究了脑葡萄糖代谢。在PVS患者中，总体脑代谢为正常值的40%。然而，有害的躯体感觉刺激激活中脑，对侧丘脑，和初级躯体感觉皮层在每一个PVS患者，即使在没有可检测的皮层诱发电位。任何患者的次级躯体感觉、双侧岛叶、后顶叶和前扣带皮层均未显示激活。此外，在PVS患者中，激活的初级躯体感觉皮层与次级躯体感觉皮层、双侧后顶叶皮层、运动前皮层、多感觉上级颞叶皮层和前额叶皮层在功能上是分离的。总之，躯体感觉刺激PVS患者，在强度引起疼痛的控制，导致增加的神经元活动在初级躯体感觉皮层，即使静息脑代谢严重受损。然而，初级皮层的这种激活似乎是孤立的，并与高级联合皮层分离。(C)2002 Elsevier Science（美国）。
The persistent vegetative state (PVS) is a devastating medical condition characterized by preserved wakefulness contrasting with absent voluntary interaction with the environment. We used positron emission tomography to assess the central processing of noxious somatosensory stimuli in the PVS. Changes in regional cerebral blood flow were measured during high-intensity electrical stimulation of the median nerve compared with rest in 15 nonsedated patients and in 15 healthy controls. Evoked potentials were recorded simultaneously. The stimuli were experienced as highly unpleasant to painful in controls. Brain glucose metabolism was also studied with [F-18]fluorodeoxyglucose in resting conditions. In PVS patients, overall cerebral metabolism was 40% of normal values. Nevertheless, noxious somatosensory stimulation-activated midbrain, contralateral thalamus, and primary somatosensory cortex in each and every PVS patient, even in the absence of detectable cortical evoked potentials. Secondary somatosensory, bilateral insular, posterior parietal, and anterior cingulate cortices did not show activation in any patient. Moreover, in PVS patients, the activated primary somatosensory cortex was functionally disconnected from secondary somatosensory, bilateral posterior parietal, premotor, polysensory superior temporal, and prefrontal cortices. In conclusion, somatosensory stimulation of PVS patients, at intensities that elicited pain in controls, resulted in increased neuronal activity in primary somatosensory cortex, even if resting brain metabolism was severely impaired. However, this activation of primary cortex seems to be isolated and dissociated from higher-order associative cortices. (C) 2002 Elsevier Science (USA).