A Functional MR Study Of The Brain In Stroke Patients With Upper-limb Paralysis Treated With Constraint-induced Movement Therapy

Part 1A fMRI Study to Explore Brain Plasticity of the Stroke with Upper-limb Paralysis Treated with Constraint-induced Movement TherapyObjective: To evaluate the correlation between the activation patterns of upper-limb stroke treated with constraint-induced movement therapy and the clinical presentation with blood oxygenation level dependent-functional MR imaging (BOLD-fMRI) in order to explore the mechanism of CIMT.Materials and Methods: 6 patients in chronic stage of infarction and 10 volunteers participated in the experiments. All of the patients have functional disturbance in right upper-limb and the volunteers are normal. The evaluation of the functional disturbance of upper-limb was performed to the subjects prior to the experiment. All of the patients were required to finish the thumb-to-index finger tapping task and underwent functional magnetic resonance imaging twice, one is before CIMT in resting state and another is after two weeks CIMT; the volunteers underwent same fMRI one time. A block design was used for the inspection. The fMRI data were analyzed with Analysis of Functional NeuroImages (AFNI) software package. Individual and group analysis was conducted then. The upper-limb function data were analysed with SPSS.Results: Before CIMT, the activated brain regions are similar to that of the volunteers only in a lower activation level and there were wide areas activated to compensate the impaired function. After CIMT, the patients show score increases on the ARAT, which indicating the affected arm function improved. These subjects also displayed cortical reorganization on fMRI. The area responsible for the hand movement shows increased activation and theactivation level of bilateral corpus striatum and thalamus increased. There arealso activated regions in contrlateral parietal lobe.Conclusion: CIMT can improve the patients' upper-limb function effectively,the increased affected arm use during CIMT appears to induce corticalreorganization as measured by fMRI. The changes on fMRI show the evidenceof neuronal reorganization and compensation induced by CIMT.Part 2 A Study of the Correlation between the MR Diffusion Tensor Imaging and the Clinical Presentation of the Upper-limb Stroke Treated with Constraint-induced Movement TherapyObjective: To evaluate the correlation between the diffusion tensor imaging(DTI) and the clinical presentation of the upper-limb stroke treated with constraint-induced movement therapy (CIMT)Materials and Methods 6 patients in chronic stage infarction and 10 volunteers participated in the experiments. All of the patients have functional disturbance in right upper-limb and the volunteers are normal. The evaluation of the functional disturbance of upper-limb was performed to the subjects prior to the experiment. The patients were required to undergo DTI scan twice, one is before CIMT and the other is after two weeks CIMT on a 3.0 T MR system. The volunteers underwent DTI scan one time, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were measured bilaterally in the lesion, precentral gyrus, postcentral gyrus, third quarter of posterior limb of the internal capsule and the cerebral peduncle, and statistical analysis was performed using t-test with SPSS.Results: Significant reduction in FA value was found in the infarction lesion and areas along with the corticospinal tract. Obvious elevation in ADC value was found in the infarction. After CIMT, the FA value in areas along with the corticospinal tract and right cerebral peduncle show elevation. ADC values show no obvious change.Conclusion: DTI can noninvasively detect and assess corticospinal tracts and its potential disorder in vivo, thus providing useful information in diagnosing and further understanding the mechanisms of rehabilitation of CIMT. It is potentially useful as a quantitative tool for monitoring the treatment process of the patient.