RESUMEN
Objective To study the correlation between regional cerebral glucose metabolism and behavioral scores in middle cerebral artery occlusion(MCAO)model rats before and after the intervention of constraint induced movement therapy(CIMT),and the correlation between the natural recovery processand motor function recovery in MCAO model rats and the brain activation after CIMT intervention,and to further explore the mechanism of CIMT. Methods Twenty-two adult male Sprague-Dawley(SD)rats were randomly divided into an ischemic group treated with CIMT (CIMT,n=6),an ischemic group (Control,n=6),a sham-operated group(Sham,n=6),and a blank control group(Normal,n=4). The MCAO models of rats in the CIMT group and Control group were established by thread embolism method. The middle cerebral artery was not blocked during the operation for the Sham group,and the Normal group was not given any special treatment. After operation,rats in the CIMT group and Sham group were treated with CIMT. On the 7th day(d7)and the 22nd day(d22)after surgery,foot-fault test(FFT)and the beam balance and walking (BBW) test were used to evaluate the forelimb motor;micro positron emission tomography-computed tomography (micro PET/CT) imaging with fluorodeoxyglucose (18F-FDG) was used to scan the glucose metabolism in different brain regions of rats;Pearson correlation analysis was used to analyze the correlation between behavioral scores and glucose metabolism level in the CIMT group and Control group. Results On d7,the BBW score in the CIMT group and Control group was negatively correlated with glucose metabolism in the left insular cortex and the auditory cortex,and positively correlated with glucose metabolism in the right posterior hippocampus,superior colliculus,and inferior colliculus,with statistically significant differences;the FFT score was negatively correlated with glucose metabolism in the left somatosensory cortex, insular cortex and orbitofrontal cortex, and positively correlated with glucose metabolism in the right midbrain,with statistically significant differences. On d22, the BBW score in the CIMT group and Control group was positively correlated with glucose metabolism in the amygdala,caudate putamen,insular cortex and entorhinal cortex,and negatively correlated with glucose metabolism in the nucleus accumbens (Acb) core shell and caudate putamen in the right brain region,with statistically significant differences;the FFT score was negatively correlated with the entorhinal cortex in the right hemisphere and the difference was statistically significant. Conclusion The recovery of motor function promoted by CIMT was associated with the activation of both cerebral hemispheres in rats. The improvement of balance function promoted by CIMT in rats with cerebral ischemia was mainly related to the activation of Acb core shell in the right hemisphere. The recovery of fine grasping function promoted by CIMT may be related to the activation of the right entorhinal cortex.
RESUMEN
<p><b>AIM</b>Study on the relationship between the degraded spinal cord injuries and the changes of the motor evoked potentials (MEP) to prove the diagnosis and prognosis value of MEP.</p><p><b>METHODS</b>After injury at T8-T9 cord using modified Allen's weight-drop method, 27 male SD rats were divided randomly into control group (n = 5), group A (50 gcf, n = 8), group B (70 gcf, n = 8) and group C (100 gcf, n = 6). MEPs elicited by monopolar transcortical stimulation were recorded continuously before injury, just after injury, 15 minutes, 1 hour, 3 hours and 6 hours after injury. The rate of the size of the bleeding or necrosis area to the total cord was also calculated.</p><p><b>RESULTS</b>MEP had no significant change in the control group. The amplitude of MEP's early components in group A or group B decreased or even obliterated after SCI, and then partially recovered, while the late components were lost without any recovery signals. All animals in group C showed no MEP waves excepting 2 rats had recovery signals. The size of the cord injuries area increased according to the dropping force and was correlated significantly with the amplitude of the largest peaks of scMEP 1 hour after SCI (r = -0.821).</p><p><b>CONCLUSION</b>The scMEP changes after SCI are correlated with the injury forces and the pathological changes in the cord, which indicates that scMEP can be used as an objective index for the cord functional monitoring.</p>