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Objective:To explore the mechanism of motor imagery training (MIT) combined with conventional rehabilitation to promote the functional recovery of upper limbs in stroke survivors. To explore the brain network reorganization resulting when motor imagery training (MIT) is combined with conventional rehabilitation to promote the motor recovery of stroke survivors.Methods:Fourteen hemiplegic patients were recruited as the MIT group. They underwent 4 weeks of MIT (30 min/day, 5 days/week) along with conventional rehabilitation treatment. The upper limb section of the Fugl-Meyer assessment (FMA-UE) and the modified Barthel Index (MBI) were used to assess all of the patients, and resting-state fMRI was performed before and after the treatment. Twenty-eight age- and sex-matched healthy subjects also received one-time resting-state fMRI scanning. Granger causal analysis was performed in the MIT group to calculate the changes in effective connection between the ipsilesional primary motor cortex and the whole brain before and after the treatment, and the results were compared with the healthy control group.Results:After the treatment, the average FMA-UE and MBI of the MIT group had increased significantly. Before the intervention, the effective connection mode of the ipsilesional M1 area in the MIT group was significantly different from that of the healthy controls. The causal flow from the ipsilesional M1 area to the bilateral prefrontal cortex had increased abnormally and the causal flow from the contralesional primary motor cortex, the inferior parietal lobule and the cerebellum to the ipsilesional M1 area had decreased significantly. After the treatment, the effective connection pattern of the stroke survivors was nearly normal, and the causal influence from contralesional motor imagery-related brain areas (the superior parietal lobule, inferior parietal lobule, thalamus and the fusiform gyrus) to the ipsilesional M1 area was enhanced. Effective connection from the ipsilesional M1 area to the contralesional cerebellum before the intervention was positively correlated with the improvement in FMA-UE scores, and the effective connection from the contralesional middle frontal gyrus to the ipsilesional M1 area was correlated negatively.Conclusions:The neural mechanism of MIT's effectiveness when it is combined with conventional rehabilitation might be related to the reorganization of effective connections. That would include enhanced causal flow between motor imagery-related brain areas and the contralesional cerebellum and ipsilesional M1 area. Down-regulation of the effective connection from the contralesional middle frontal gyrus to the ipsilesional M1 area also occurs.
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Objective To measure the efficacy of combining motor imagery training ( MIT) with convention-al therapy in improving stroke patients′upper-extremity function. And to seek a cortical reorganization mechanism as-sociated with the improvement using resting-state functional magnetic resonance imaging ( rs-fMRI) . Methods Ten stroke survivors were selected as an experimental group. They were given motor imagery training for four weeks ( 30 minutes a day, 5 days a week) and conventional rehabilitation therapy ( 40 minutes a day, 5 days a week) . Another 10 healthy counterparts were the control group. Before and after the four weeks of treatment, both groups were as-sessed using the upper extremity Fugl-Meyer assessment ( FMA-UE) and the modified Barthel index ( MBI) . Moreo-ver, rs-fMRI was conducted to assess functional connectivity between cortical regions and the ipsilesional primary mo-tor cortex ( M1) before and after the intervention. The laterality index ( LI) of the primary motor or sensory cortex was also calculated. Results After the intervention, the average FMA-UE and MBI scores of the experimental group had increased significantly. After MIT and conventional therapy there was increased functional connectivity between the ip-silesional and contralesional M1 areas, and between the ipsilesional M1 and contralesional primary sensory cortex ( S1) and frontal lobe, the functional connection between the ipsilesional M1 and the ipsilesional paracentral lobule and the anterior cingutate was also increased. More specifically, the LI relating M1 and S1 decreased after the inter-vention, tending toward the normal level. LIMI decreased significantly. Conclusion The 4-week regimen of motor imagery training and conventional therapy resulted in functional improvement in the upper limbs and greater ability in the activities of daily living. The observed improvements may be due to cortical reorganization, including better func-tional connectivity between the bilateral M1 areas and increased connectivity between the ipsilesional M1 area and some non-motor areas. There is some recovery of symmetry in the bilateral primary motor cortex.
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@#Objective To investigate the relationship between disrupted corticospinal tract (CST) and motor recovery after stroke by using diffusion tensor tracking (DTT). Methods From March, 2012 to June, 2013, 15 chronic stroke patients with left subcortical lesions and 15 age- and sex- matched healthy subjects were performed diffusion tensor imaging (DTI) examination. The CST was tracked by DTT technique, and the damaged values of the CST caused by the stroke lesions were quantified using a CST template generated from healthy controls. Furthermore, the correlations of the damaged values of the CST with Fugl-Meyer Assessment (FMA) were performed. Results The range of the damaged values of CST in stroke patients was 0.00% to 29.6%. There were very strong negative correlation between the damaged values of the CST and FMA scores (the wrist, r = -0.660; hand, r = -0.813; wrist plus hand, r = -0.795, respectively, P < 0.01). It also showed strong negative correlation between the damaged values of the CST and FMA scores (upper limb, r = -0.614; upper limb plus lower limb, r = -0.563, respectively, P < 0.05). Whereas, there was no correlation between the damaged values of the CST and FMA scores of lower limb (r = -0.270, P = 0.331). In addition, the lesion volumes of stroke and FMA scores were not significantly correlated (P > 0.05). Conclusion The severity of motor deficit after stroke was closely related to the overlap of lesions with CST. The damaged values of the CST based on DTT may be used as a potential biomarker to assess motor impairments of upper limbs, especially hand and wrist in stroke patients.
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Objective To assess any differences in brain activation during active,passive and imaginary movement of the hands using blood oxygen level-dependent functional magnetic resonance imaging (fMRI),and to provide references for the cortical reorganization in patients with brain injuries.Methods Twenty healthy,righthanded,adult volunteers were studied,fMRI was performed during active,passive and imaginary fist clutching.Whole brain analysis and group analysis were applied to get the voxels,the volume of activation,the peak t-score and its coordinates.Results Active and passive movement both produced significant activation in the contralateral sensorimotor cortex,the contralateral supplementary motor area and the ipsilateral cerebellum.The sensorimotor cortex was the most frequently and most strongly activated brain area.Imaginary movement produced significant bilateral activation in the supplementary motor area.Conclusions Active and passive movement induce similar brain activation patterns.This indicates that passive might replace active movement when observing activation of the brain's cortex during the rehabilitation of patients with hemiplegia.
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Objective To assess differences in brain activation between active and passive movement of the right hand using blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI). Methods Nine healthy adult right handed volunteers were studied. fMRI was performed with active and passive finger-to-finger movement. Results Right hand active and passive movement produced significant activation in the contralateral sensorimotor cortex ( SMC ), the contralateral premotor cortex ( PMC ), bilaterally in the supplementary motor area (SMA) and in the ipsilateral cerebellum. The activated brain areas were centered on the contralateral SMC and PMC and located more forward during active movement than during passive movement. The contralateral SMC was the most strongly and the most frequently activated brain area. The contralateral posterior parietal cortex (PPC) was less relevant to the hand movements. Unlike active movement, passivemovement activated more areas in the posterior central gyrus than in the anterior central gyrus. Conclusions Both active and passive movement significantly activate the brain areas which are responsible for hand movement, but there are some differences in the locations of the cortex areas activated and in the incidence activation except in the contralateral SMC.
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Objective To investigate the brain metabolic changes and evaluate their spatial distributions after traumatic axonal injury (TAI)in rats by using proton magnetic resonance spectroscopy(1H-MRS).Methods The TAI model was made by subjecting the head of the rats to the linear and angular accelerations.The multi-voxel MRS was employed to detect the tissue metabolic state at the levels of hippocampus-caudate and pons prior to injury and at 24 hours after injury.The alterations of NAA/Cr,NAA/Cho and Cho/Cr values as well as the spatial distribution of NAA/Cr reduction were accessed. Immunohistochemical staining for β-APP was used to observe the injured axons. Results A siguificantdecrease in NAA/Cr and NAA/Cho(P<0.05)and subtle increase in Cho/Cr(P>0.05)were observed in rats at 24 hours after TAI in comparison to the pre-injury levels.Notable decrease in NAA/Cr value was observed in the areas including the brain stem,hippocampus,internal capsule,corpus callosum and thalamus,where axonal injuries were confirmed by the histological examination. Conclusion Metabolic imbalances Occur in the brains of rats with TAI.with notable changes in the brain stem and the hippocampus.
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Objective To study the effects of RNA interference(RNAi)-mediated silencing of mitofusin-2 (Mfn2) gene on glycornetabolism and insulin resistance in BALB/c mice. Methods Mfn2 short hairpin RNA (shRNA) and negative control green fluorescent protein(GFP) -expressed plasmid vectors were constructed. 44 mice were randomly divided into transfection group (Mfn2) and negative control group (HK). 1.5 ml GFP-expressed plasmid(negative control or Mfn2 shRNA,75 μg for each mouse)was injected into the mice in 5 seconds through vena caudalis. Five days later, intraperitoneal glucose tolerance test (IPGTT) and intraperitoneal insulin tolerance test(IPITT)were performed to evaluate glycometabolism and insulin sensitivity. D-3-[3~H]-glucose in PBS buffer were injected via the tail vein. Blood samples were taken at specific time points. Radioactivity was measured in all samples with liquid scintillation counter. The rates of hepatic glucose production in vivo were calculated. Mfn2 protein expression in hepatic tissue was detected by Western blot. Results Compared with HK mice, the Mfn2 expressions of Mfn2 mice decreased markedly(8.05±0.15 vs 8.56±0.01 ,P<0.05). The fasted blood glucose leves [(6.95±0. 83 vs 4.68±0. 29) mmol/L,P<0. 05] in Mfn2 mice were higher than those in HK mice. The insulin sensitivity of Mfn2 mice decreased markedly compared with HK mice. The rate of hepatic glucose production was significantly elevated in Mfn2 mice [(49.53±16.31)μmol·kg~(-1)·min~(-1)],compared with negative control mice[(24.91±4.07)μmol·kg~(-1)·min~(-1),P<0.05].Conclusion The down-regulatd expression of Mfn2 induces glycometabolic disorder and insulin resistance in BALB/c mice. Mfn2 plays an important role in maintaining glucose homeostasis in vivo.
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OBJECTIVE:To investigate the effect of electrolytes on the stability of the total parenteral nutrient(TPN) solutions.METHODS:The pH values and number changes of solution microparticles of 4 groups of TPN sample solutions that of different electrolytes were determined at 0h after preparation and 4 hours,8hours,12hours,16hours and 24hours,respectively after storage under room temperature(20℃～22℃). And the appearances of which were observed under naked eyes. RESUL_ TS:No changes were noted as for the pH of 4 groups of solutions within 24h.For the numbers of microparticles(≥5?m),those in Group 4(to which group valence 1 and valence 2 electrolytes were added) showed a rapid increase to peak value from the very start;while those of the other groups increased with the extension of storage time.Stratification appeared in Group 3(to which group,valence 2 electrolytes had been added) and Group 4(to which group,valence 1 and valence 2 electrolytes were added) 6 hours after preparation.Curdling reaction was noted in Group 2(to which group,valence 1 electrolytes had been added) at 12th hour.Neither sediments nor stratification appeared in Group 1(no electrolytes were added to which group).CONCLUSION:El_ectrolytes have certain influences on the stability of the TPN solutions.Care should be taken to the dosage of which at preparation.Furthermore,once prepared,the solution should be infused as soon as possible and the storage of which should not beyond 24h.
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Objective To evaluate the diagnostic value of dynamic contrast-enhanced MR angiography(DCE MRA)of the renal arteries.Methods 18 patients suspected with renal arterial diseases underwent DCE MR Angiography examinations.After 20 ml(0.15～0.20 mmol/kg)Gd-DTPA being injected quickly via cubital vein,a scaning and data acquisition with coronal three-demensional fast spoiled gradient(FSPGR)sequence was performed in a breath-hold time,the source images were introduced into work station for post processing,including maximum intensity projection(MIP)and multiplanner reconstruction(MPR),finally 3D DCE MRA images were obtained.Results A comparative study on renal artery stenosis and its degree between DCE MR angiography and DSA was done in 25 arteial segments of 12 cases.In 12 normal renal arteries shown by DSA,DCE MRA found 11 normal and one mild stenosis;Four moderate and one severe stenosis was shown by DCE MRA in five renal arteries with moderate stenosis identified by DSA;DCE MRA found five severe stenosis and three occlusion of renal anteries,which had accordance with DSA findings.Conclusion Dynamic contrast-enhanced MR angiography can accurately assess renal arterial diseases,the accuracy was especially higher in patients with severe arterial stenosis and occlusion.
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OBJECTIVE:To study the occurrence of adverse drug reaction(ADR)in our hospital and its relevant factors in order to improve the rational drug use level in the clinic.METHODS:A total of 134 cases of ADR reports collected in our hospital in 2006 were classified and analyzed statistically.RESULTS:Of the 134 cases,99 kinds of drugs were involved(in different dosage forms and specifications),leading the list were anti-infectives(34 kinds,34,34%),followed by Chinese drug preparations.Intravenous infusion(94 cases/times,59.49%)was the main route of administration;and the main types of ADR were lesions of skin and accessories.CONCLUSION:Great importance should be attached to ADR monitoring to promote rational drug use in the clinic.