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Objective:To observe the functional remodeling of the default mode network (DMN) of patients with post-stroke cognitive impairment (PSCI) in response to transcranial direct current stimulation (tDCS) and to explore the mechanisms involved.Methods:Eighteen PSCI patients and twenty healthy controls were enrolled. The PSCI patients were given 20 minutes of tDCS at 2.0mA on the dorsolateral prefrontal cortex every weekday for four weeks. The subjects were scanned using resting state functional magnetic resonance imaging before and after the intervention to explore any functional changes in the DMN. Montreal cognitive assessment (MoCA) scoring was performed before and after the treatment.Results:Compared to the healthy controls, the cognitively impaired patients showed significant abnormalities in the DMN on admission, including decreased functinal connection (FC) in the posterior cingulate cortex and/or precuneus (PCC/PCu), as well as increased FC in the medial prefrontal cortex (MPFC) and left hippocampus. After the treatment, a significant improvement in the PSCI patients′ average MoCA score was observed. The average FC of the PCC/PCu had also increased significantly, while that of the left hippocampus had decreased significantly, on average. The FC in the PCC/PCu after tDCS was found to be positively related to the MoCA score measured at 4 weeks after admission.Conclusions:PSCI patients show functional abnormalities in the DMN. tDCS applied to their dorsolateral prefrontal cortex can significantly improve their average MoCA scores, which may be related to the increasing FC of the PCC/PCu.
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Objective To investigate the structural changes during the early stage of spinal cord injury,and the relationships between these structural changes and patients' motor recovery.Methods The clinical data of 25 patients with spinal cord injury collected from 2012 October to 2014 March were analyzed retrospectively.The spinal cord injury patients were split into two groups (Good recoverers group and Poor recoverers group) according to the clinical outcome of motor recovery at 6 months follow-up,and there were 10 Good recoverers (ASIA grade:1 A,4 B,3 C,and 2 D) and 15 Poor recoverers (ASIA grade:7 A,3 B,3 C,and 2 D).The study also recruited 25 matched healthy controls.The mean age of Good recoverers,Poor recoverers and healthy controls were 37.9± 13.9,35.8± 11.5 and 36.5±9.3,respectively.Structural MRI was used to investigate the regions with brain structural changes among the three groups.Pearson correlation analysis was used to explore the relationships between these structural changes and patients' motor recovery.Results Compared to healthy controls group,both poor recoverers and good recoverers had significantly decreased cortical thickness in the bilateral primary motor cortex.Poor recoverers exhibited more serious and widespread structural damages,in addition to reduced cortical thickness in the primary motor cortex,poor recoverers also showed decreased cortical thickness in the right SMA and premotor cortex when compared to healthy controls.Compared to the healthy controls group,poor recoverers showed reduced white matter volume in the right primary motor cortex and posterior limb of the internal capsule;good recoverers showed no significant difference in white matter microstructure.Furthermore,these structural changes at the internal capsule and primary motor cortex were associated with the motor recovery rate at 6 months follow-up (r=0.75,P＜ 0.001;r=0.76,P＜ 0.001,respectively).Conclusion These findings suggest that spinal cord injury causes significant anatomical changes in the human sensorimotor system in the early phase,and these structural changes directly affect the motor recovery of spinal cord injury.Future treatment aimed at promoting neural function recovery of spinal cord injury patients should pay close attention to the injured brain.
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Objective To compare the short‐term clinical effects of single segment and two segments of Dynesys dynamic in‐ternal fixation system for treating lumbar degenerative disease .Methods 40 cases of degenerative lumbar disease treated by the Dynesys dynamic fixation system combined with posterior approach decompression from 2009 July to March 2012 were selected and performed the evaluation on the clinical effects by the waist and leg pain visual analogue scale (VAS) ,the Oswestry disability index (ODI) and the orthopaedic spinal association of North America (NASS) index .The imaging method was used to observe the mobili‐ty of operative segment and proximal adjacent segment and the degenerative change of intervertebral height .Results All of the 40 cases were followed up .The VAS score and ODI score at postoperative 3 months and last follow‐up were significantly decreased when compared with the pre‐operative scores (P 0 .05) .The NASS index showed no statistically significant difference in the postoperative effect satisfaction between the two groups (P>0 .05);there was no statistically significant difference in the variation of the intervertebral height between before operation and at the last follow‐up (P>0 .05) .There was statistically significant difference in the motility of proximal adjacent segment at the last follow‐up between the two groups (P<0 .05);but comparing the motility of proximal adjacent segment between the last follow‐up and pre‐operation , only the single segment group showed statistically significant difference (P< 0 .05) .Conclusion The Dynesys dynamic fixation system combined with posterior approach decompression operation has good clinical effect in the treatment of lumbar degenerative disease .Meanwhile ,the single segment method has more significant effect on the motility of proximal adjacent segment than the double segments method .