Friedman D B, Friberg L, Payne G, Mitchell J H, Secher N H
Department of Clinical Physiology and Nuclear Medicine, Bispjeberg Hospital, Copenhagen, Denmark.
J Appl Physiol (1985). 1992 Nov;73(5):2120-5. doi: 10.1152/jappl.1992.73.5.2120.
Regional cerebral blood flow (rCBF) was measured at orbitomeatal (OM) plane +5.0 and +9.0 cm in 10 subjects at rest and during dynamic hand contractions before and after axillary blockade. Handgrip strength was significantly reduced, and rating of perceived exertion increased after blockade. During hand contractions before blockade, contralateral hemispheric cerebral blood flow (CBF) at OM +9.0 increased from a resting value of 58 (49-75) to 63 (52-82) ml.100 g-1.min-1; contralateral motor sensory rCBF at OM +9 from 58 (50-77) to 71 (64-84); motor sensory rCBF at OM +5 from 67 (54-76) to 77 (64-87) and 70 (62-84) contralaterally and ipsilaterally, respectively; and supplementary motor area (SM) rCBF from 64 (53-69) to 75 (67-88) ml.100 g-1.min-1. During dynamic hand contractions after axillary blockade, CBF did not increase at OM +5 or in the SM. Furthermore, contralateral motor sensory rCBF at OM +9 increased much less. Axillary blockade had no effect on resting CBF, rCBF, or increases in the two during hand contractions of the opposite hand. Thus neural feedback from the contracting muscle is necessary for the increases in SM bilateral OM +5 motor sensory rCBF and the maximal increase in contralateral OM +9 motor sensory rCBF during dynamic hand contractions.
在10名受试者休息时以及腋窝阻滞前后进行动态手部收缩时，于眶耳（OM）平面+5.0和+9.0 cm处测量局部脑血流量（rCBF）。阻滞术后，握力显著降低，自觉用力程度评分增加。在阻滞前的手部收缩过程中，OM +9.0处对侧半球脑血流量（CBF）从静息值58（49 - 75）增加至63（52 - 82）ml·100 g⁻¹·min⁻¹；OM +9处对侧运动感觉rCBF从58（50 - 77）增加至71（64 - 84）；OM +5处运动感觉rCBF对侧和同侧分别从67（54 - 76）增加至77（64 - 87）和70（62 - 84）；辅助运动区（SM）rCBF从64（53 - 69）增加至75（67 - 88）ml·100 g⁻¹·min⁻¹。在腋窝阻滞后的动态手部收缩过程中，OM +5处或SM区的CBF未增加。此外，OM +9处对侧运动感觉rCBF增加也少得多。腋窝阻滞对静息CBF、rCBF或对侧手部收缩时二者的增加均无影响。因此，在动态手部收缩过程中，收缩肌肉的神经反馈对于SM区双侧OM +5运动感觉rCBF的增加以及对侧OM +9运动感觉rCBF的最大增加是必要的。
