Cramer Steven C, Parrish Todd B, Levy Robert M, Stebbins Glenn T, Ruland Sean D, Lowry David W, Trouard Theodore P, Squire Scott W, Weinand Martin E, Savage Cary R, Wilkinson Steven B, Juranek Jenifer, Leu Szu-Yun, Himes David M
Department of Anatomy, University of California, Irvine, CA, USA.
Stroke. 2007 Jul;38(7):2108-14. doi: 10.1161/STROKEAHA.107.485631. Epub 2007 May 31.
A number of therapies in development for patients with central nervous system injury aim to reduce disability by improving function of surviving brain elements rather than by salvaging tissue. The current study tested the hypothesis that, after adjusting for a number of clinical assessments, a measure of brain function at baseline would improve prediction of behavioral gains after treatment.
Twenty-four patients with chronic stroke underwent baseline clinical and functional MRI assessments, received 6 weeks of rehabilitation therapy with or without investigational motor cortex stimulation, and then had repeat assessments. Thirteen baseline clinical/radiological measures were evaluated for ability to predict subsequent trial-related gains.
Across all patients, bivariate analyses found that greater trial-related functional gains were predicted by (1) smaller infarct volume, (2) greater baseline clinical status, and (3) lower degree of activation in stroke-affected motor cortex on baseline functional MRI. When these 3 variables were further assessed using multivariate linear regression modeling, only lower motor cortex activation and greater clinical status at baseline remained significant predictors. Note that lower baseline motor cortex activation was also associated with larger increases in motor cortex activation after treatment.
Lower motor cortex activity at baseline predicted greater behavioral gains after therapy, even after controlling for a number of clinical assessments. The boosts in cortical activity that paralleled behavioral gains suggest that in some patients, low baseline cortical activity represents underuse of surviving cortical resources. A measure of brain function might be important for optimal clinical decision-making in the context of a restorative intervention.
目前针对中枢神经系统损伤患者研发的多种疗法旨在通过改善存活脑区的功能而非挽救组织来减少残疾。本研究检验了这样一个假设，即在对多项临床评估进行调整后，基线时的脑功能指标将改善对治疗后行为改善的预测。
24例慢性卒中患者接受了基线临床和功能磁共振成像评估，接受了为期6周的康复治疗，治疗中有无试验性运动皮层刺激，然后进行重复评估。评估了13项基线临床/放射学指标预测后续试验相关改善的能力。
在所有患者中，双变量分析发现，更大的试验相关功能改善可由以下因素预测：（1）梗死体积较小，（2）基线临床状态较好，（3）基线功能磁共振成像显示卒中影响的运动皮层激活程度较低。当使用多元线性回归模型进一步评估这3个变量时，只有较低的运动皮层激活和较好的基线临床状态仍然是显著的预测因素。注意，较低的基线运动皮层激活也与治疗后运动皮层激活的更大增加有关。
即使在对多项临床评估进行控制之后，基线时较低的运动皮层活动仍可预测治疗后更大的行为改善。与行为改善平行的皮层活动增强表明，在一些患者中，低基线皮层活动代表了对存活皮层资源的利用不足。在恢复性干预的背景下，脑功能指标对于优化临床决策可能很重要。
