Non-invasive brain stimulation is a technology that uses magnetic field or electric field to act on the brain to adjust the activity of cerebral cortex neurons. It mainly includes transcranial magnetic stimulation and transcranial direct current stimulation. The principle is to accelerate the induction of neuroplasticity by changing the excitability of the cerebral cortex. The characteristics are noninvasive, safe and that the patient can tolerate it. This article mainly introduces the theoretical foundation and mechanisms of non-invasive brain stimulation, and its application and safety in stroke complications, neuropathic pain and epilepsy, and discusses the commonly used treatment regimens of non-invasive brain stimulation in different neurological diseases, in order to provide possible treatment reference for the rehabilitation of neurological diseases.
A realizaton project of electrical stimulator aimed at motor dysfunction of stroke is proposed in this paper. Based on neurophysiological biofeedback, this system, using an ARM9 S3C2440 as the core processor, integrates collection and display of surface electromyography (sEMG) signal, as well as neuromuscular electrical stimulation (NMES) into one system. By embedding Linux system, the project is able to use Qt/Embedded as a graphical interface design tool to accomplish the design of stroke rehabilitation apparatus. Experiments showed that this system worked well.
Bone marrow-derived mesenchymal stem cells (BMSCs) for repairing damaged heart tissue are a new kind of important treatment options because of their potential to differentiate into cardiomyocytes. We in this experiment investigated the effect of different electrical stimulation time on the expression of myocardial specificity gene and protein in rat bone marrow mesenchymal stem cells (rBMSCs) in vitro. The rBMSCs of second or third generation were randomly divided into three groups, i.e. electrical stimulation (ES) group, 5-Azacytidine (5-Aza) group and the control group. The rBMSCs in the ES groups with complete medium were exposed to 2 V, 2 Hz, 5 ms electrical stimulation for 0.5 h, 2 h, 4 h, and 6 h respectively every day for 10 days. Those in the 5-Aza group were induced by 5-Aza (10 μmol/L) for 24 h, and then cultured with complete medium for 10 days. Those in the control group were only cultured with complete medium, without any treatment, for 10 days. The rBMSCs' morphological feature in each group was observed with inverted phase microscope. The mRNA expression of myocyte-specific enhancer factor 2C (MEF-2C) and connexin 43 (Cx43) were examined with Real-Time quantitative PCR and the protein expression of MEF-2C, Cx43 were detected with Western Blot method. The results showed that the mRNA expression level of the MEF-2C, Cx43 and the protein expression level of MEF-2C, Cx43 were significantly higher in the ES group and 5-Aza group than those in the relative control group (P < 0.05). It suggests that electrical stimulation could play a part of role in the induction of the rBMSCs to differentiate into the cariomyocyte-like cells in vitro and the effectiveness of the electrical stimulation with 2 h/d had the best in our experiement. But the mechanism how electrical stimulation promotes the differentiation of rBMSC into cardiomyocyte is still unclear.
As an emerging non-invasive brain stimulation technique, transcranial direct current stimulation (tDCS) has received increasing attention in the field of stroke disease rehabilitation. However, its efficacy needs to be further studied. The tDCS has three stimulation modes: bipolar-stimulation mode, anode-stimulation mode and cathode-stimulation mode. Nineteen stroke patients were included in this research (10 with left-hemisphere lesion and 9 with right). Resting electroencephalogram (EEG) signals were collected from subjects before and after bipolar-stimulation, anodal-stimulation, cathodal-stimulation, and pseudo-stimulation, with pseudo-stimulation serving as the control group. The changes of multi-scale intrinsic fuzzy entropy (MIFE) of EEG signals before and after stimulation were compared. The results revealed that MIFE was significantly greater in the frontal and central regions after bipolar-stimulation (P < 0.05), in the left central region after anodal-stimulation (P < 0.05), and in the frontal and right central regions after cathodal-stimulation (P < 0.05) in patients with left-hemisphere lesions. MIFE was significantly greater in the frontal, central and parieto-occipital joint regions after bipolar-stimulation (P < 0.05), in the left frontal and right central regions after anodal- stimulation (P < 0.05), and in the central and right occipital regions after cathodal-stimulation (P < 0.05) in patients with right-hemisphere lesions. However, the difference before and after pseudo-stimulation was not statistically significant (P > 0.05). The results of this paper showed that the bipolar stimulation pattern affected the largest range of brain areas, and it might provide a reference for the clinical study of rehabilitation after stroke.
Clinical trials have demonstrated that kilohertz-frequency transcutaneous spinal cord stimulation (TSCS) can be used to facilitate the recovery of sensory-motor function for patients with spinal cord injury, whereas the neural mechanism of TSCS is still undetermined so that the choice of stimulation parameters is largely dependent on the clinical experience. In this paper, a finite element model of transcutaneous spinal cord stimulation was used to calculate the electric field distribution of human spinal cord segments T12 to L2, whereas the activation thresholds of spinal fibers were determined by using a double-cable neuron model. Then the variation of activation thresholds was obtained by varying the carrier waveform, the interphase delay, the modulating frequency, and the modulating pulse width. Compared with the sinusoidal carrier, the usage of square carrier could significantly reduce the activation threshold of dorsal root (DR) fibers. Moreover, the variation of activation thresholds was no more than 1 V due to the varied modulating frequency and decreases with the increased modulating pulse width. For a square carrier at 10 kHz modulated by rectangular pulse with the frequency of 50 Hz and the pulse width of 1 ms, the lowest activation thresholds of DR fibers and dorsal column fibers were 27.6 V and 55.8 V, respectively. An interphase delay of 5 μs was able to reduce the activation thresholds of the DR fibers to 20.1 V. The simulation results can lay a theoretical foundation on the selection of TSCS parameters in clinical trials.
Meige Syndrome (MS) is a neurological disorder characterized by blepharospasm, oromandibular dystonia, and spasmodic torticollis as its primary clinical manifestations. With advancements in neuroscience research and the accumulation of clinical experience, significant progress has been made in understanding the pathophysiological mechanisms, diagnostic criteria, and therapeutic strategies for MS both domestically and internationally. To standardize clinical practice and promote academic development, Neuro-ophthalmology Group of Ophthalmology Branch of Chinese Medical Association, in collaboration with Neuro-ophthalmology Society, Chinese Research Hospital Association, organized a panel of authoritative experts. This expert panel conducted a comprehensive review of the latest research evidence and clinical experiences. Through multiple rounds of expert consultations and in-depth discussions, the original consensus was thoroughly revised and updated. The new consensus aims to provide standardized diagnostic and treatment guidelines for clinicians, foster research innovation and the development of therapeutic techniques in the field of neuro-ophthalmology, address new challenges in the diagnosis and treatment of MS, and ultimately improve patients' quality of life.
In the treatment of drug-refractory epilepsy in children, surgical treatment has a good clinical effect. However, for children whose surgical site is difficult to determine and who cannot undergo resectional surgery, neuromodulation techniques are one of the treatments that can be considered. At present, new neuromodulation technologies in children mainly include transcutaneous vagus nerve stimulation (transcutaneous auricular vagus nerve stimulation, ta-VNS), deep brain stimulation (deep brain stimulation, DBS), reactive nerve stimulation (responsive neurostimulation, RNS), transcranial magnetic stimulation (transcranial magnetic stimulation, TMS), transcranial direct current stimulation (transcranial direct current stimulation, TDCS) and transcranial alternating current stimulation (transcranial alternating current stimulation, TACS). This article briefly discussed the clinical efficacy and safety of various currently available neuromodulation technologies, so as to provide a reference for the rational selection and application of neuromodulation technologies, and improve the clinical efficacy and quality of life of children with drug-refractory epilepsy.
This article presents a transcutaneous electric stimulator that is based on chaotic signal. Firstly, we in the study used the MATLAB platform in the PC to generate chaotic signal through the chaos equation, and then we transferred the signal out by data acquisition equipment of USB-6251 manufactured by NI Company. In order to obtain high-power signal for transcutaneous electric stimulator, we used the chip of LM3886 to amplify the signal. Finally, we used the power-amplified chaotic signal to stimulate the internal nerve of human through the electrodes fixed on the skin. We obtained different stimulation effects of transcutaneous electric stimulator by changing the parameters of chaotic model. The preliminary test showed that the randomness of chaotic signals improved the applicability of electrical stimulation and the rules of chaos ensured that the stimulation was comfort. The method reported in this paper provides a new way for the design of transcutaneous electric stimulator.
ObjectiveTo investigate the effects of transcranial direct current stimulation (tDCS) combined with virtual reality (VR) on upper limb dysfunction of stroke patients.MethodsPatients with stroke who were hospitalized in the Department of Rehabilitation Medicine, the Third Affiliated Hospital of Sun Yat-Sen University from July 2018 to January 2020 were selected. The patients were divided into tDCS group, VR group and combined treatment group by random number table method. All three groups received conventional rehabilitation treatment. Based on this, tDCS group received 2.0 mA tDCS treatment, VR group received 20 min VR treatment, and combined treatment group received the same tDCS and VR treatment. Before and 4 weeks after treatment, the Fugl-Meyer assessment-upper limb (FMA-UL), Wolf motor function test (WMFT) and modified barthel index (MBI) were used to evaluate the upper limb motor function and activities of daily life (ADL) of the three groups.ResultsA total of 45 patients were included, 15 in each group. No adverse reactions or fall off occurred during the treatment. Before treatment, there were no significant difference in FMA-UL, WMFT-Times, WMFT functional ability scores (WMFT-FAS), and MBI between the three groups (P>0.05). After 4 weeks of treatment, the FMA-UL, WMFT-Times, WMFT-FAS, and MBI scores of the three groups were significantly improved compared with those before treatment (P<0.05); the MBI score of the combination treatment group was significantly better than the tDCS group and VR group, and the FMA-UL was significantly better than the tDCS group, and the differences were statistically significant (P<0.05). Also, there were no significant differences in the improvement of FMA-UL, WMFT-Times, WMFT-FAS, and MBI scores between the tDCS group and the VR group (P>0.05); the differences of FMA-UL, WMFT-Times, WMFT-FAS, and MBI scores before and after treatment in the combined treatment group, which were significantly better than those in tDCS group and VR group (P<0.05). ConclusiontDCS combined with virtual reality can significantly improve the upper limb motor function and ADL ability of stroke patients, and the effect is superior to tDCS or VR treatment solely.
Transcranial direct current stimulation (tDCS) is a brain stimulation intervention technique, which has the problem of different criteria for the selection of stimulation parameters. In this study, a four-layer real head model was constructed. Based on this model, the changes of the electric field distribution in the brain with the current intensity, electrode shape, electrode area and electrode spacing were analyzed by using finite element simulation technology, and then the optimal scheme of electrical stimulation parameters was discussed. The results showed that the effective stimulation region decreased and the focusing ability increased with the increase of current intensity. The normal current density of the quadrilateral electrode was obviously larger than that of the circular electrode, which indicated that the quadrilateral electrode was more conducive to current stimulation of neurons. Moreover, the effective stimulation region of the quadrilateral electrode was more concentrated and the focusing ability was stronger. The focusing ability decreased with the increase of electrode area. Specifically, the focusing tended to increase first and then decrease with the increase of electrode spacing and the optimal electrode spacing was 64.0–67.2 mm. These results could provide some basis for the selection of electrical stimulation parameters.