ObjectivesTo systematically review the efficacy of repetitive transcranial magnetic stimulation (rTMS) on rehabilitation of unilateral neglect in stroke patients.MethodsPubMed, The Cochrane Library, PEDro, EMbase, CNKI, WanFang Data and VIP databases were searched online for randomized controlled trials (RCTs) of rTMS on rehabilitation of unilateral neglect in stroke patients from inception to March 2017. Two reviewers independently screened literature, extracted data and assessed the quality of included studies. Meta-analysis was then performed by using RevMan 5.3 software.ResultsA total of 12 RCTs involving 303 patients were included. The results of meta-analysis showed that: the stimulate group was superior to the control group in line bisection test (MD=–5.54, 95%CI –6.79 to –4.29, P<0.000 01), line cancellation test (MD=–3.75, 95%CI –4.60 to –2.90,P<0.000 1) and star cancellation test (MD=–22.94, 95%CI –26.52 to –19.35,P<0.000 01). However, there was no significant difference in the score of the modified Barthel index between two groups (MD=3.91, 95%CI–9.52 to 17.34,P=0.57).ConclusionsrTMS appears to improve the symptoms of unilateral neglect in stroke patients. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify above conclusions.
ObjectiveTo systematically evaluate the effect of repeated transcranial magnetic stimulation (rTMS) in treating epilepsy.MethodsThe randomized controlled trials (RCTs) of rTMS for epilepsy and related diseases were collected from PubMed, EMbase, Cochrane Library, CBM, CNKI, VIP, and Wanfang databases by computer. The retrieval time was from establishment to June 2019. Two researchers independently screened the literature, extracted the data and evaluated the deviation risks of the included studies. RevMan5.3 software was used for Meta analysis.ResultsA total of 21 RCTs were included, including 1 587 patients. The results showed that rTMS assisted antiepileptics drugs (AEDs) could improve the effective rate of epilepsy treatment [RR=1.28, 95% CI (1.19, 1.37)], significantly reduced HAMA, HAMD and NFDS scores in the treatment of patients with epilepsy combined with anxiety and depression [MD=−3.94, 95% CI (−4.25, −3.63)], and improve DQ and GMFM-88 scores in children with cerebral palsy combined with epilepsy [MD=7.95, 95% CI (7.00, 8.90)]. In addition, using rTMS will not cause additional adverse reaction [peto OR=0.52, 95% CI (0.31, 0.84)].ConclusionsThe current evidence showed that rTMS combined AEDs can improve the efficient of AEDs therapy. When treat anxiety depression comorbidity, it can significantly reduce the anxiety depression score. In addition in children with cerebral palsy merger, it can improve muscle strength and development. And rTMS will not cause additional adverse reactions. Limited by the quantity and quality of the selected studies, the conclusions need to be verified by more high-quality studies.
Currently, transcranial magnetic stimulation (TMS) has been widely used in the treatment of depression, Parkinson’s disease and other neurological diseases. To be able to monitor the brain’s internal activity during TMS in real time and achieve better treatment outcomes, the researchers proposed combining TMS with neuroimaging methods such as magnetic resonance imaging (MRI), both of which use Tesla-level magnetic fields. However, the combination of strong current, large magnetic field and small size is likely to bring physical concerns which can lead to mechanical and thermal instability. In this paper, the MRI static magnetic field, the TMS coil and human head model were built according to the actual situations. Through the coupling of the magnetic field and the heat transfer module in the finite element simulation software COMSOL, the force and temperature of the TMS coil and head were obtained when the TMS was used in combination with MRI (TMS-MRI technology). The results showed that in a 3 T MRI environment, the maximum force density on the coil could reach 2.51 × 109 N/m3. Both the direction of the external magnetic field and the current direction in the coil affected the force distributions. The closer to the boundary of the external magnetic field, the greater the force. The magnetic field generated by the coil during TMS treatment increased the temperature of the brain tissue by about 0.16 °C, and the presence of the MRI static magnetic field did not cause additional thermal effects. The results of this paper can provide a reference for the development of the use guidelines and safety guidelines of TMS-MRI technology.
Existing neuroregulatory techniques can achieve precise stimulation of the whole brain or cortex, but high-focus deep brain stimulation has been a technical bottleneck in this field. In this paper, based on the theory of negative permeability emerged in recent years, a simulation model of magnetic replicator is established to study the distribution of the induced electric field in the deep brain and explore the possibility of deep focusing, which is compared with the traditional magnetic stimulation method. Simulation results show that a single magnetic replicator realized remote magnetic source. Under the condition of the same position and compared with the traditional method of stimulating, the former generated smaller induced electric field which sharply reduced with distance. By superposition of the magnetic field replicator, the induced electric field intensity could be increased and the focus could be improved, reducing the number of peripheral wires while guaranteeing good focus. The magnetic replicator model established in this paper provides a new idea for precise deep brain stimulation, which can be combined with neuroregulatory techniques in the future to lay a foundation for clinical application.
In transcranial magnetic stimulation (TMS), the conductivity of brain tissue is obtained by using diffusion tensor imaging (DTI) data processing. However, the specific impact of different processing methods on the induced electric field in the tissue has not been thoroughly studied. In this paper, we first used magnetic resonance image (MRI) data to create a three-dimensional head model, and then estimated the conductivity of gray matter (GM) and white matter (WM) using four conductivity models, namely scalar (SC), direct mapping (DM), volume normalization (VN) and average conductivity (MC), respectively. Isotropic empirical conductivity values were used for the conductivity of other tissues such as the scalp, skull, and cerebrospinal fluid (CSF), and then the TMS simulations were performed when the coil was parallel and perpendicular to the gyrus of the target. When the coil was perpendicular to the gyrus where the target was located, it was easy to get the maximum electric field in the head model. The maximum electric field in the DM model was 45.66% higher than that in the SC model. The results showed that the conductivity component along the electric field direction of which conductivity model was smaller in TMS, the induced electric field in the corresponding domain corresponding to the conductivity model was larger. This study has guiding significance for TMS precise stimulation.
Transcranial magnetic stimulation (TMS), a widely used neuroregulatory technique, has been proven to be effective in treating neurological and psychiatric disorders. The therapeutic effect is closely related to the intracranial electric field caused by TMS, thus accurate measurement of the intracranial electric field generated by TMS is of great significance. However, direct intracranial measurement in human brain faces various technical, safety, ethical and other limitations. Therefore, we have constructed a brain phantom that can simulate the electrical conductivity and anatomical structure of the real brain, in order to replace the clinical trial to achieve intracranial electric field measurement. We selected and prepared suitable conductive materials based on the electrical conductivity of various layers of the real brain tissue, and performed image segmentation, three-dimensional reconstruction and three-dimensional printing processes on each layer of tissue based on magnetic resonance images. The production of each layer of tissue in the brain phantom was completed, and each layer of tissue was combined to form a complete brain phantom. The induced electric field generated by the TMS coil applied to the brain phantom was measured to further verify the conductivity of the brain phantom. Our study provides an effective experimental tool for studying the distribution of intracranial electric fields caused by TMS.