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ObjectiveTo explore the difference of learning and memory function between permanent cerebral ischemia and ischemia-reperfusion rat models by filament-occluded method after three weeks of natural recovery, and to observe the changes of brain structure. MethodsA total of 21 SPF male Sprague-Dawley rats were randomly divided into sham group (n = 7), permanent ischemia group (n = 7) and ischemia-reperfusion group (n = 7). The latter two group underwent left middle cerebral artery occlusion, and the ischemia-reperfusion group was reperfused after 90 minutes of ischemia. All the rats were tested with Morris Water Maze 16 to 22 days after modeling, to record escape latency in the navigation experiment, as well as first latency, platform quadrant swimming time ratio and distance ratio, boundary swimming time ratio and distance ratio, average speed, and the swimming path in the space exploration experiment. On the 22nd day after modeling, four rats with similar Longa scores in each group were scanned by magnetic resonance by diffusion tensor imaging, to measure the fractional anisotropy (FA) of cerebral ischemic cortex, striatum, hippocampus and their corresponding contralateral regions, to calculate ratio of FA (rFA); as well as the volume of infarct (VI) and ratio of VI (rVI). ResultsFor navigation experiment, the escape latency decreased in all the groups with the time (F = 36.202, P < 0.001), but it was not significant for the permanent ischemia group (F = 4.004, P > 0.05). The escape latency was longer in the permanent ischemia group than in the other two groups at each time points (P < 0.05). For space exploration experiment, the boundary time ratio and distance ratio were more in the permanent ischemia group and the ischemia-reperfusion group than in the sham group (P < 0.017), and the first latency was longer in the permanent ischemia group than in the sham group (P < 0.017). The swimming path of ischemia-reperfusion group and sham operation group was better than that of the permanent ischemia group. FA and rFA in left cortex and striatum were less in the permanent ischemia group and the ischemia-reperfusion group than in the sham group (P < 0.05), while FA and rFA of left cortex and FA of left striatum were less in the permanent ischemia group than in the ischemia-reperfusion group (P < 0.05). The VI and rVI were larger in the permanent ischemia group than in the ischemia-reperfusion group (t > 4.185, P < 0.01). FA and rFA of left cortex and striatum correlated with escape latency, boundary time ratio and distance ratio (|r| > 0.498, P < 0.05). The VI and rVI correlated with escape latency and boundary time ratio (|r| > 0.538, P < 0.05). ConclusionCognitive impairment is more severe in the rat model of permanent cerebral ischemia, which may relate to the larger damage of structure of nerve fibers in ischemic cortex and striatum, and larger infarct size.
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@#Objective To explore the rehabilitation and outcome of motor neuron syndrome and Sjögren's syndrome. Methods A patient with motor neuron syndrome and Sjögren's syndrome was reviewed. Results The patient expressed progressive quadriparesis and slurred speech. Electromyogramphy displayed upper and lower motor neuron damage. Sonography showed diffuse lesions in parotid gland and submandibular gland. Laboratory tests displayed markedly elevated levels of SSA and Ro52 antibodies. After a course of intravenous immunoglobulin (IVIG) and four weeks of comprehensive rehabilitation, the patient improved in terms of speech, muscle strength, balance, posture control and activities of daily living. She failed to achieve further improvement after another IVIG and glucocorticoid two months later, but fortunately her symptoms did not deteriorate. Conclusion The patient with motor neuron syndrome and Sjögren's syndrome might benefit from IVIG and appropriate rehabilitation.
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Objective To explore the effects of early exercise on motor function and the mechanism in rats after focal cerebral ischemia. Methods 21 Sprague-Dawley male rats were divided into control group (n=7), natural recovery group (n=7) and exercise training group (n=7), and the latter 2 groups were modeled with middle cerebral artery occlusion. The exercise training group received wheel running exercise 24 hours after modeling for 14 days. They were assessed with Rogers score and beam balance test 21 days after modeling. 4 rats in each group received routine MRI and diffusion tensor imaging (DTI) scanning. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of ischemic (L) and contralateral side (R) were measured, and the rate of them (L/R, r) was calculated. Results There was significant difference in Rogers score among the groups (Z=-0.786, P0.05). Beam balance score of the natural recovery group was significantly different from the control group and the exercise training group (F=38.11, P0.05). The LFA of the natural recovery group was significantly different from the control group (P0.05);while the rFA of the natural recovery group was significantly different from the control group and the exercise training group (F=19.30, P0.05). LFA and rFA strongly correlated with all the behavior scores (r=-0.90--0.70, P0.05). DTT showed that the direction and density of neural fibers were significantly asymmetrical in the natural re-covery group and the exercise training group, and more symmetrical in the exercise training group. Conclusion Early exercise can promote the neural functional recovery in rats after focal cerebral ischemia, which may associate with the improve of conduction of fibers.
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Objective To explore the effect of exercise training on learning and memory ability in rats with focal cerebral ischemia, and to analyze the changes of brain tissue structure of rats after exercise training through diffusion tensor imaging (DTI). Methods Twenty-four SPF male Sprague-Dawley rats were randomly divided into sham operation group (n=8), natural recovery group (n=8) and exercise training group (n=8). The left middle cerebral artery occlusion (MCAO) model was established. The exercise training group received running wheel training 24 hours after modeling, for 14 days. All groups were tested by the Morris water maze 15 days after modeling. The latency in the navigation experiment, as well as the first latency, boundary swimming time ratio, the boundary swimming distance ratio, the average speed and the swimming path in the space exploration experiment were recorded. Four rats with similar Longa scores in each group received rou-tine magnetic resonance imaging and DTI scanning, the fractional anisotropy (FA), axial diffusivity (λ‖), and radial diffusivity (λ⊥) of isch-emic cortex and hippocampal lesion and contralateral side were measured. Results In the navigation experiment, the latency of three groups showed a downward trend along with training days (P0.05), while it was shorter in the exercise train-ing group than in the natural recovery group in the same time (P2.627, P2.521, P0.05). The swimming paths in the exercise training group and the sham operation group were better than that of the natural recovery group. The FA and rFA in the left cortical area were higher in the sham operation group than in the exercise training group and the natural recovery group (P0.05). There was no significant difference in the FA in the right cortical area among three groups (F=0.532, P=0.607). Theλ⊥,λ‖, rλ‖and rλ⊥in the left cortical area were lower in the sham opera-tion group than in the natural recovery group (P0.05). There was no significant difference in theλ⊥andλ‖in the right cortical area among three groups (F0.05). There was no significant difference in the FA,λ⊥,λ‖and rFA, rλ⊥and rλ‖in the bilateral hippo-campal interest area among three groups (F0.05). The rFA, rλ‖, rλ⊥and leftλ⊥ were correlated with the latency in the space ex-ploration experiment in the Morris water maze test (P<0.05), in which the correlation coefficient of rλ⊥was the highest (r=0.761, P<0.01). Conclusion Proper exercise training can improve the learning and memory ability of rats with focal cerebral ischemia, and can promote the repair of nerve fiber damage and reduce the vascular edema. In addition, the rFA, rλ‖, rλ⊥andλ⊥of ischemic cortex may be predictors of cognitive function recovery in rats after focal cerebral ischemia, especially rλ⊥.
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@#There are many ways to prepare middle cerebral artery occlusion (MCAO) rat model. The focal cerebral ischemia model es-tablished by the suture-occluded method is widely accepted as an ideal focal cerebral ischemia model, which can be used in the basic and clinical study of cerebral vascular diseases. However, it still has the defects of high technical requirement, large model difference and high animal mortality. A variety of focal cerebral ischemia models were established by changing the retention time of the thread, the road the thread plugging into, the type of thread bolt and the depth of the thread plugging. This article compared different suture-occluded method, as well as the suture-occluded method to other modeling methods, different cerebral ischemia models may be different in the pathophysiology of cerebral infarction, and the effects may also be different.
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@#The neuromechanism of language function recovery in patients with aphasia after stroke is still unclear. It is supported that the language function of aphasia after extensive damage of left hemisphere mainly recovered through activating the right hemisphere of ho-mologous regions to improve the function of speech. Melodic intonation therapy (MIT) can be achieved by melody tone and left hand clap to activate the right hemisphere of the frontal temporal lobe, which is particularly applicable to improve language function of non-fluent aphasia patients with large left hemisphere lesion. Non-invasive brain stimulation techniques (NBS) changes brain activity through stimulat-ing affected or contralateral side, which has been used to facilitate language functional recovery after stroke. Excitatory transcranial stimula-tion on the right hemisphere homology combined with melodic intonation therapy can promote language recovery of patients with extensive damage of left hemisphere after stroke. It is valuable to combine traditional speech training with MIT and NBS to activate related language functional areas to maximum improvement of language recovery after stroke.