Neural Plasticity最新文献

Background and Purpose: Motor impairment is a common occurrence in patients with acute basal ganglia (BG) ischemic stroke (ABGIS). However, the underlying mechanisms of poststroke motor dysfunction remain incompletely elucidated. In this study, we employed multifrequency band wavelet transform-based amplitude of low-frequency fluctuations (Wavelet-ALFFs) to investigate the alterations of spontaneous regional neural activity in patients with ABGIS. Methods: A total of 39 ABGIS patients with motor dysfunction and 45 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging. Wavelet-ALFF values were calculated in the conventional frequency band (0.01-0.08 Hz), slow-5 frequency band (0.01-0.027 Hz), and slow-4 frequency band (0.027-0.073 Hz). A two-sample t-test was performed to compare the Wavelet-ALFF values between the two groups with sex as a covariate and Gaussian random field (GRF) theory (voxel p < 0.001, cluster p < 0.05, two-tailed) was used for the multiple corrections. Furthermore, spearman correlation analysis was performed to assess the relationship between alterations in regional neural activity between Fugl-Meyer Assessment (FMA) and National Institutes of Health Stroke Scale (NIHSS) scores. Results: In comparison to HCs, patients with ABGIS showed significantly increased Wavelet-ALFF in the left middle temporal gyrus (MTG) and decreased Wavelet-ALFF in the right inferior frontal operculum (IFO) across all three frequency bands (conventional, slow-4, and slow-5). In the left superior occipital gyrus (SOG), Wavelet-ALFF was decreased in the conventional frequency band but increased in the slow-4 frequency band. Additionally, patients with ABGIS demonstrated reduced Wavelet-ALFF in the right superior temporal gyrus (STG) in the conventional and slow-4 frequency bands. In the slow-5 frequency band, increased Wavelet-ALFF was observed in the left calcarine cortex (CC), left middle frontal gyrus (MFG), left supramarginal gyrus (SMG), and left postcentral gyrus (PCG), while decreased Wavelet-ALFF was noted in the right precuneus (PCu). Correlation analysis revealed that increased Wavelet-ALFF in the left CC in the slow-5 frequency band was positively correlated with the FMA score. No other correlations were detected in the conventional and slow-4 frequency bands. Conclusions: The altered spontaneous neural activity was frequency-specific in patients with ABGIS, and the slow-5 frequency band exhibited better results. Furthermore, the relationship between spontaneous brain activity and clinical characteristics highlighted patterns of neural alterations associated with motor dysfunction. These findings may provide novel insights into the neural mechanisms underlying motor dysfunction in ABGIS.

Objective: To demonstrate the utility of somatosensory evoked potentials (SEPs) following median nerve stimulation for chronological assessment of sensory function in patients with subacute stroke during rehabilitation. Design: Retrospective study. Patients: Forty-seven patients with hemiparesis due to stroke during the subacute phase. Methods: We screened 363 patients who underwent SEP measurements at a rehabilitation hospital. Among them, 47 who underwent SEP measurements within 1 week after admission and at least 2 weeks after the initial assessment were included in this study. Sensorimotor assessments, including the Semmes-Weinstein monofilament test (SWMT), pain sensation, position sensation, two-point discrimination, and Stroke Impairment Assessment Set (SIAS) motor tests simultaneously with SEP measurements were available for 20 of the 47 patients. The relationship between the SEP peak count and each sensorimotor assessment was examined. Results: SEP amplitudes and latencies showed no significant differences between the initial and second assessments (paired t-test, p  > 0.05). However, the counts of SEP peaks after NI (N20) increased (Wilcoxon signed-rank test, p  < 0.05), indicating changes in the SEP waveform. Furthermore, strong correlations were observed between SEP peak counts, stage, and all functional assessments (counts and SWMT, RS = -0.77, p < 0.001; counts and pain sensation, RS = -0.71, p < 0.001; counts and position sensation, RS = 0.75, p < 0.001; counts and two-point discrimination, RS = -0.74, p < 0.001; stage and SWMT, RS = -0.74, p < 0.001; stage and pain sensation, RS = -0.69, p < 0.001; stage and position sensation, RS = 0.74, p < 0.001; and stage and two-point discrimination, RS = -0.75, p < 0.001; all Spearman's rank correlation coefficients). Conclusion: Despite the limitations of the retrospective study design, our study highlights the utility of SEPs for evaluating sensory function in patients with subacute stroke, setting the foundation for further investigations on the use of SEPs to assess functional changes in patients with subacute stroke undergoing rehabilitation.

The phenomenon of neural plasticity pertains to the intrinsic capacity of neurons to undergo structural and functional reconfiguration through learning and experiential interaction with the environment. These changes could manifest themselves not only as a consequence of various life experiences but also following therapeutic interventions, including the application of noninvasive brain stimulation (NIBS) and psychotherapy. As standalone therapies, both NIBS and psychotherapy have demonstrated their efficacy in the amelioration of psychiatric disorders' symptoms, with a certain variability in terms of effect sizes and duration. Consequently, scholars suggested the convenience of integrating the two interventions into a multimodal treatment to boost and prolong the therapeutic outcomes. Such an approach is still in its infancy, and the physiological underpinnings substantiating the effectiveness and utility of combined interventions are still to be clarified. Therefore, this opinion paper aims to provide a theoretical framework consisting of compelling arguments as to why adding NIBS to psychotherapy can promote therapeutic change. Namely, we will discuss the physiological effects of the two interventions, thus providing a rationale to explain the potential advantages of a combined approach.

Background: Stroke survivors exhibit persistent abnormal gait patterns, particularly in diminished walking ability and stability, limiting mobility and increasing the risk of falling. The purpose of the study was to determine the effects of repetitive transcranial magnetic stimulation (rTMS) coupled with cycling exercise on walking ability and stability in patients with stroke and explore the potential mechanisms underlying motor cortex recovery. Methods: In this double-blinded randomized pilot trial, 32 stroke patients were randomly separated into the real-rTMS group (RG, receiving rTMS during active cycling exercise) and the sham-rTMS group (SG, receiving sham rTMS during active cycling exercise). Participants completed 10 exercise sessions (5 times per week). Lower extremity function was measured using the Fugl-Meyer assessment of lower extremity (FMA-LE), and functional balance ability was measured by the Berg balance scale (BBS). The 2-min walk test (2MWT) and standing balance test were employed to evaluate walking and balance ability. Motor evoked potentials (MEPs) were measured to evaluate cortical excitability. The above assessments were administered at baseline and after the intervention. Additionally, the cycling exercise performance was recorded after the initial and final exercise sessions to evaluate the motor control during exercise. Results: The RG showed significant improvements in lower extremity function (FMA-LE) and functional balance ability (BBS) compared to the SG at postintervention. The walking and balance abilities, as well as the motor asymmetry of cycling exercise, significantly improved in RG. Additionally, participants in RG exhibited a higher elicitation rate of ipsilesional MEPs than that in SG. The improvements in motor asymmetry of cycling exercise in RG were significantly associated with increases in FMA-LE scores and walking ability. Conclusion: The combination of rTMS and cycling exercise effectively improves walking ability and walking stability in patients with stroke, which may be related to the excitability modulation of the motor cortex induced by rTMS. Trial Registration: Clinical Trial Registry identifier: ChiCTR2400079360.

Although previous studies have shown that repetitive transcranial magnetic stimulation (rTMS) can ameliorate addictive behaviors and cravings, the underlying neural mechanisms remain unclear. This study aimed to investigate the effect of high-frequency rTMS with the left dorsolateral prefrontal cortex (L-DLPFC) as a target region on smoking addiction in nicotine-dependent individuals by detecting the change of spontaneous brain activity in the reward circuitry. We recruited 17 nicotine-dependence participants, who completed 10 sessions of 10 Hz rTMS over a 2-week period and underwent evaluation of several dependence-related scales, and resting-state fMRI scan before and after the treatment. Functional connectivity (FC) analysis was conducted with reward-related brain regions as seeds, including ventral tegmental area, bilateral nucleus accumbens (NAc), bilateral DLPFC, and bilateral amygdala. We found that, after the treatment, individuals showed reduced nicotine dependence, alleviated tobacco withdrawal symptoms, and diminished smoking cravings. The right NAc showed increased FC with right fusiform gyrus, inferior temporal gyrus (ITG), calcarine fissure and surrounding cortex, superior occipital gyrus (SOG), lingual gyrus, and bilateral cuneus. No significant FC changes were observed in other seed regions. Moreover, the changes in FC between the right NAc and the right ITG as well as SOG before and after rTMS were negatively correlated with changes in smoking scale scores. Our findings suggest that high-frequency L-DLPFC-rTMS reduces nicotine dependence and improves tobacco withdrawal symptoms, and the dysfunctional connectivity in reward circuitry may be the underlying neural mechanism for nicotine addiction and its therapeutic target.