Regional cerebral blood flow during self-paced repetitive Iifting tasks with a precision grip

用1-123IMP示踪剂SPECT测量静息、握持和自定步速重复举起小物体时的局部血流量(RCBF)。对于举重任务，测试了两种物体重量条件：一种是恒重(400g)，另一种是变重(200、400和600g)。在所有情况下，视觉输入都是使用眼罩最小化的。用SPM对rCBF的增减进行统计学检验。当举起恒定重量时，对侧初级运动皮质和初级感觉皮质的面积显著增加。对侧辅助运动区也有增加的趋势。此外，在与视力相关的对侧区域(Brodman区8、37和17)观察到rCBF显著降低。研究结果表明，这些是用精确握法控制举重任务的主要和必要的区域。当变重条件与恒重条件比较时，对侧扣带回的rCBF显著增加，与Brodman‘s区24/32相对应。对侧额前下部皮质(11区)和同侧枕区(Brodman‘s区2/40)也有明显增加。结果表明，这些区域在快速调整抓取力以适应被提升物体重量变化的控制中起着重要作用。

Regional Blood flow (rCBF) was measured using a SPECT with 1-123 IMP tracer during resting, holding and self-paced repetitive lifiting of a small object with the precision grip. For the lifting task, two object weight conditions were tested ; one with a constant weight (400g) and the other with variable weights (200,400 and 600g). In all conditions, visual input was minimized using an eyemask. A SPM was used to test the rCBF increase and decrease statistically. There was no significant rCBF increase or decrease due to holding of the object, while during lifting a constant weight, there was a significant increase in the areas of contra lateral primary motor cortex and primary sensory cortex. A tendency of increase was also revealed for the contra lateral supplementary motor area. In addition, a significant rCBF decrease was observed in the contralateral areas related to vision (Brodman's area 8,37, and 17). The findings suggest that these are the primary and essential areas for the control of lifting tasks with the precision grip. When the variable weight condition was compared with the constant weight condition, a significant rCBF increase was found for the contralateral cingulate gyrus which corresponded to Brodman's areas 24/32. There was also significant increase in the contra lateral inferior prefronal cortex (area 11) and the ispliateral occipital region (Brodman's areas 2/40). The results thus suggest that these areas plays an important role in the control of quickly adjusting the grasp forces to the changes in weight of objects being lifted.