[Noninvasive brain stimulation in the rehabilitation of patients with post-stroke aphasia]

[The effect of non-invasive brain stimulation on neuroplasticity in the early recovery period after ischemic stroke]

The post-stroke cognitive impairment syndrome (PSCI) develops in 10-80% cases of ischemic stroke and leads to a significant patients' quality of life impairment. The standard program of cognitive rehabilitation includes nootropic agents therapy and neuro-cognitive training. The additional various methods of non-invasive brain stimulation (NIBS) application can improve the results of PSCI rehabilitation.

PURPOSE OF THE STUDY

Studying the different variants of NIBS influence on synaptic neuroplasticity in the early recovery period after ischemic stroke.

MATERIAL AND METHODS

The rehabilitation of 62 patients with PSCI syndrome after ischemic stroke outcomes were studied. The patients were assigned to 5 groups. Patients from the control group underwent standardized nootropic therapy and course sessions with a neuropsychologist. The rest of the patients were divided into 4 groups, in which, in addition to the basic program of cognitive rehabilitation, different options for the course use of NIBS were used: photochromotherapy (PCT) with narrow-band optical radiation (NOR) with a wavelength of 530 nm (green light); rhythmic transcranial magnetic stimulation (rTMS) with a low-intensity high-frequency running pulsed magnetic field; infrared radiation with a wavelength of 1-56 microns, modulated by terahertz frequencies (IRMT); bioacoustic correction (BAC). We analyzed the dynamics of changes in scores of MMSE scales, FAB, Roshchina. In order to assess the effect of NIBS on neuroplasticity, the concentrations of BDNF and antibodies to the NR2 fragment of the NMDA receptor were evaluated before and after the completion of the rehabilitation course.

RESULTS

Concentration values of antibodies to the NR2 subunit of the NMDA receptor in all groups remained consistently above the norm (more than 2 ng/ml) throughout the entire course of rehabilitation. Differences between groups in the dynamics of BDNF concentration in the peripheral blood were revealed. There was a significant (p<0.05) decrease in its concentration by almost 2 times by the end of rehabilitation course in control group. In the rTMS and IRMT groups, a decrease in the BDNF concentration was also recorded in dynamics, which, however, did not reach a significant level. There was no decrease in BDNF levels in the BAC group. There was an increase of this level in the PCT group.

CONCLUSION

The use of different types of NIBS in the program of cognitive rehabilitation of patients with PSCI syndrome contributes to an increase in the rehabilitation potential due to the activation of neurotrophin-mediated synaptic neuroplasticity. Green light PCT and BAC have the greatest effect on increasing neuroplasticity after ischemic stroke.

Activation of ephrinb1/EPHB2/MAP-2/NMDAR Mediates Hippocampal Neurogenesis Promoted by Transcranial Direct Current Stimulation in Cerebral-Ischemic Mice

tDCS, a new, safe, non-invasive physical therapy method, is often used in motor dysfunction rehabilitation. However, the effects and underlying mechanisms of tDCS on hippocampal neurogenesis after cerebral ischemia (CI) are still unclear. This study aimed to investigate the promotive effect and mechanism of repetitive anodal-tDCS on hippocampal neurogenesis after CI in mice. The CI model in mice was established using bilateral common carotid artery occlusion (BCCAO). The pathological changes in the hippocampal CA1 region and cognitive function were assessed by hematoxylin and eosin staining and Morris water maze test, respectively. Hippocampal neurogenesis was observed by immunofluorescence staining. The levels of expression of ephrinb1, EPHB2, MAP-2, and NMDAR in the hippocampi were analyzed by qRT-PCR and Western blotting. Compared with the sham mice, the model mice showed significant neuronal damage in the hippocampal CA1 region (P < 0.01), cognitive dysfunction (P < 0.01), and endogenous hippocampal neurogenesis (P < 0.01). These results suggested that the CI model was successfully established, and that CI could promote endogenous hippocampal neurogenesis, but this hippocampal neurogenesis was unable to recover cognitive dysfunction. Compared with the model mice, the tDCS mice had ameliorated pathological damage in the CA1 region (P < 0.01), improved cognitive function (P < 0.01), increased hippocampal neurogenesis (P < 0.01), and increased mRNA and protein expression of ephrinb1, EPHB2, MAP-2, and NMDAR (P < 0.05). Repetitive anodal-tDCS can promote hippocampal neurogenesis and improve cognitive function in CI mice. The effect may be related to the activation of the ephrinb1/EPHB2/MAP-2/NMDAR signaling pathway.