BACKGROUND

Stroke is a significant health concern globally, and dysphagia has been a very common complication. Early intervention for managing dysphagia is challenging with a lack of universally accepted treatment protocols. Noninvasive repetitive transcranial magnetic stimulation (rTMS) is emerging as a treatment option for stroke dysphagia. However, there is no standardized rTMS treatment protocol for it, leading to challenges in clinical decision-making.

To determine available rTMS protocols for unilateral hemispheric stroke dysphagia.

A scoping review using PubMed, ProQuest, and EBSCOHost databases was conducted using the keywords “dysphagia,” “stroke,” “repetitive transcranial magnetic stimulation,” “conventional therapy,” and “swallowing examination.” Eligible studies published from inception to April 2020 were appraised using the Oxford Centre for Evidence-Based Medicine and analyzed qualitatively.

Out of 42 articles, five randomized controlled trials met the eligibility criteria. A total of 108 patients with stroke and oropharyngeal dysphagia were randomized into one of the following treatment groups: (1) rTMS (unilateral or bilateral); (2) conventional dysphagia therapy (CDT); and (3) combined intervention (CI) of rTMS and CDT. The CI gave significant improvements in swallowing function and quality of life compared to CDT alone. The bilateral rTMS protocol resulted in more significant improvements than unilateral rTMS.

There are various and heterogeneous treatment protocols involving neuromodulation available for stroke dysphagia. The combination of bilateral excitatory-inhibitory rTMS and CDT seems to result in an optimal outcome for swallowing function among patients with unilateral hemispheric stroke dysphagia.

Intermittent theta burst stimulation (iTBS), a time-saving and cost-effective repetitive transcranial magnetic stimulation regime, has been shown to improve cognition in patients with Alzheimer's disease (AD). However, the specific mechanism underlying iTBS-induced cognitive enhancement remains unknown. Previous studies suggested that mitochondrial functions are modulated by magnetic stimulation. Here, we showed that iTBS upregulates the expression of iron-sulfur cluster assembly 1 (ISCA1, an essential regulatory factor for mitochondrial respiration) in the brain of APP/PS1 mice. In vivo and in vitro studies revealed that iTBS modulates mitochondrial iron-sulfur cluster assembly to facilitate mitochondrial respiration and function, which is required for ISCA1. Moreover, iTBS rescues cognitive decline and attenuates AD-type pathologies in APP/PS1 mice. The present study uncovers a novel mechanism by which iTBS modulates mitochondrial respiration and function via ISCA1-mediated iron-sulfur cluster assembly to alleviate cognitive impairments and pathologies in AD. We provide the mechanistic target of iTBS that warrants its therapeutic potential for AD patients.
Humans ; Mice ; Animals ; Transcranial Magnetic Stimulation ; Alzheimer Disease/therapy* ; Cognitive Dysfunction/therapy* ; Cognition ; Sulfur ; Iron ; Iron-Sulfur Proteins ; Mitochondrial Proteins

Background: Stroke is a significant health concern globally, and dysphagia has been a very common complication. Early intervention for managing dysphagia is challenging with a lack of universally accepted treatment protocols. Non-invasive repetitive transcranial magnetic stimulation (rTMS) is emerging as a treatment option for stroke dysphagia. However, there is no standardized rTMS treatment protocol for it, leading to challenges in clinical decision-making. Objective: To determine available rTMS protocols for unilateral hemispheric stroke dysphagia. Methods: A scoping review using PubMed, ProQuest, and EBSCOHost databases was conducted using the keywords “dysphagia,” “stroke,” “repetitive transcranial magnetic stimulation,” “conventional therapy,” and “swallowing examination.” Eligible studies published from inception to April 2020 were appraised using the Oxford Centre for Evidence-Based Medicine and analyzed qualitatively. Results: Out of 42 articles, five randomized controlled trials met the eligibility criteria. A total of 108 patients with stroke and oropharyngeal dysphagia were randomized into one of the following treatment groups: (1) rTMS (unilateral or bilateral); (2) conventional dysphagia therapy (CDT); and (3) combined intervention (CI) of rTMS and CDT. The CI gave significant improvements in swallowing function and quality of life compared to CDT alone. The bilateral rTMS protocol resulted in more significant improvements than unilateral rTMS. Conclusion There are various and heterogeneous treatment protocols involving neuromodulation available for stroke dysphagia. The combination of bilateral excitatory-inhibitory rTMS and CDT seems to result in an optimal outcome for swallowing function among patients with unilateral hemispheric stroke dysphagia.
Deglutition Disorders ; Transcranial Magnetic Stimulation ; Stroke

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 ; Diffusion Tensor Imaging ; Electric Conductivity ; Electricity ; Scalp

OBJECTIVE: To observe the effect of Kaiqiao Jieyin acupuncture (acupuncture for opening orifices and relieving aphasia) combined with repetitive transcranial magnetic stimulation (rTMS) on language ability and daily life communication ability in patients with post-stroke aphasia (PSA). METHODS: Fifty-six patients with PSA were randomly divided into an observation group and a control group, 28 cases in each group. Both groups received routine symptomatic treatment. The control group was treated with speech rehabilitation training and rTMS. On the basis of the treatment in the control group, the observation group was treated with Kaiqiao Jieyin acupuncture at the speech area Ⅰ, Fengchi (GB 20), Tongli (HT 5), Lianquan (CV 23), Panglianquan (Extra), etc. Panglianquan (Extra) on both sides were connected to electroacupuncture, with intermittent wave, 2 Hz in frequency. The above treatment was performed once a day for 5 consecutive days, followed by 2 days of rest for 2 weeks. The scores of western aphasia battery (WAB, including scores of spontaneous speech, auditory comprehension, repetition, naming and score of aphasia quotient [AQ]) and communication abilities in daily living (CADL) in the two groups were compared before and after treatment. RESULTS: After treatment, the spontaneous speech, auditory comprehension, repetition, naming scores and AQ scores in both groups were higher than those before treatment (P<0.05), and the increase in the observation group was greater than the control group (P<0.05). The CADL scores of the two groups were higher than those before treatment (P<0.05). CONCLUSION Kaiqiao Jieyin acupuncture combined with rTMS can improve the language ability and daily life communication ability of PSA patients.
Humans ; Transcranial Magnetic Stimulation ; Stroke Rehabilitation ; Treatment Outcome ; Aphasia/therapy* ; Acupuncture Therapy

Weightlessness in the space environment affects astronauts' learning memory and cognitive function. Repetitive transcranial magnetic stimulation has been shown to be effective in improving cognitive dysfunction. In this study, we investigated the effects of repetitive transcranial magnetic stimulation on neural excitability and ion channels in simulated weightlessness mice from a neurophysiological perspective. Young C57 mice were divided into control, hindlimb unloading and magnetic stimulation groups. The mice in the hindlimb unloading and magnetic stimulation groups were treated with hindlimb unloading for 14 days to establish a simulated weightlessness model, while the mice in the magnetic stimulation group were subjected to 14 days of repetitive transcranial magnetic stimulation. Using isolated brain slice patch clamp experiments, the relevant indexes of action potential and the kinetic property changes of voltage-gated sodium and potassium channels were detected to analyze the excitability of neurons and their ion channel mechanisms. The results showed that the behavioral cognitive ability and neuronal excitability of the mice decreased significantly with hindlimb unloading. Repetitive transcranial magnetic stimulation could significantly improve the cognitive impairment and neuroelectrophysiological indexes of the hindlimb unloading mice. Repetitive transcranial magnetic stimulation may change the activation, inactivation and reactivation process of sodium and potassium ion channels by promoting sodium ion outflow and inhibiting potassium ion, and affect the dynamic characteristics of ion channels, so as to enhance the excitability of single neurons and improve the cognitive damage and spatial memory ability of hindlimb unloading mice.
Animals ; Mice ; Transcranial Magnetic Stimulation ; Hindlimb Suspension ; Neurons ; Cognitive Dysfunction ; Brain

Humans ; Transcranial Magnetic Stimulation ; Pain Management ; Psychotic Disorders/therapy* ; Depressive Disorder, Major ; Treatment Outcome ; Transcranial Direct Current Stimulation

The optimal protocol for neuromodulation by transcranial direct current stimulation (tDCS) remains unclear. Using the rotarod paradigm, we found that mouse motor learning was enhanced by anodal tDCS (3.2 mA/cm²) during but not before or after the performance of a task. Dual-task experiments showed that motor learning enhancement was specific to the task accompanied by anodal tDCS. Studies using a mouse model of stroke induced by middle cerebral artery occlusion showed that concurrent anodal tDCS restored motor learning capability in a task-specific manner. Transcranial in vivo Ca²⁺ imaging further showed that anodal tDCS elevated and cathodal tDCS suppressed neuronal activity in the primary motor cortex (M1). Anodal tDCS specifically promoted the activity of task-related M1 neurons during task performance, suggesting that elevated Hebbian synaptic potentiation in task-activated circuits accounts for the motor learning enhancement. Thus, application of tDCS concurrent with the targeted behavioral dysfunction could be an effective approach to treating brain disorders.
Transcranial Direct Current Stimulation/methods* ; Motor Cortex/physiology* ; Neurons ; Transcranial Magnetic Stimulation

OBJECTIVE: To observe the impacts of acupuncture on depressive mood and sleep quality in patients with comorbid mild-to-moderate depressive disorder and insomnia, and explore its effect mechanism. METHODS: A total of 60 patients with comorbid mild-to-moderate depressive disorder and insomnia were randomly divided into an observation group (30 cases, 1 case dropped off) and a control group (30 cases, 2 cases dropped off). In the observation group, acupuncture and low frequency repeated transcranial magnetic stimulation (rTMS) were combined for the intervention. Acupuncture was applied to Baihui (GV 20), Yintang (GV 24⁺), Neiguan (PC 6) and Yanglingquan (GB 34), etc., the needles were retained for 30 min; and the intradermal needles were embedded at Xinshu (BL 15) and Danshu (BL 19) for 2 days. After acupuncture, the rTMS was delivered at the right dorsolateral prefrontal cortex (R-DLPFC), with 1 Hz and 80% of movement threshold, lasting 30 min in each treatment. In the control group, the sham-acupuncture was adopted, combined with low frequency rTMS. The acupoint selection and manipulation were the same as the observation group. In the two groups, acupuncture was given once every two days, 3 times weekly; while, rTMS was operated once daily, for consecutive 5 days a week. The duration of treatment consisted of 4 weeks. Hamilton depression scale-17 (HAMD-17) and Pittsburgh sleep quality index (PSQI) scores were observed before and after treatment, as well as 1 month after the treatment completion (follow-up period) separately. Besides, the levels of nerve growth factor (BDNF) and γ-aminobutyric acid (GABA) in the serum were detected before and after treatment in the two groups. RESULTS: After treatment and in follow-up, the HAMD-17 scores were lower than those before treatment in the two groups (P<0.05), and the scores in the observation group were lower than the control group (P<0.05). After treatment, the total scores and the scores of each factor of PSQI were reduced in the two groups in comparison with those before treatment except for the score of sleep efficiency in the control group (P<0.05); the total PSQI score and the scores for sleep quality, sleep latency, sleep efficiency and daytime dysfunction in the observation group were all lower than those in the control group (P<0.05). In the follow-up, except for the scores of sleep duration and sleep efficiency in the control group, the total PSQI score and the scores of all the other factors were reduced compared with those before treatment in the two groups (P<0.05); the total PSQI score and the scores of sleep quality, sleep latency, sleep duration, sleep efficiency and daytime dysfunction in the observation group were lower than the control group (P<0.05). After treatment, the levels of serum BDNF and GABA were increased in comparison with those before treatment in the observation group (P<0.05), and the level of serum BDNF was higher than that in the control group (P<0.05). CONCLUSION Acupuncture relieves depressive mood and improves sleep quality in patients with comorbid mild-to-moderate depressive disorder and insomnia. The effect mechanism may be related to the regulation of BDNF and GABA levels and the promotion of brain neurological function recovery.
Humans ; Sleep Initiation and Maintenance Disorders/therapy* ; Transcranial Magnetic Stimulation ; Brain-Derived Neurotrophic Factor ; Treatment Outcome ; Acupuncture Therapy ; Acupuncture Points ; gamma-Aminobutyric Acid ; Depressive Disorder

OBJECTIVES: To compare the effects of electroacupuncture (EA) with different time intervals on corticospinal excitability of the primary motor cortex (M1) and the upper limb motor function in healthy subjects and observe the after-effect rule of acupuncture. METHODS: Self-comparison before and after intervention design was adopted. Fifteen healthy subjects were included and all of them received three stages of trial observation, namely EA₀ group (received one session of EA), EA_6h group (received two sessions of EA within 1 day, with an interval of 6 h) and EA_48h group (received two sessions of EA within 3 days, with an interval of 48 h). The washout period among stages was 1 week. In each group, the needles were inserted perpendicularly at Hegu (LI 4) on the left side, 23 mm in depth and at a non-acupoint, 0.5 cm nearby to the left side of Hegu (LI 4), separately. Han's acupoint nerve stimulator (HANS-200A) was attached to these two needles, with continuous wave and the frequency of 2 Hz. The stimulation intensity was exerted higher than the exercise threshold (local muscle twitching was visible, and pain was tolerable by healthy subjects, 1-2 mA ). The needles were retained for 30 min. Using the single pulse mode of transcranial magnetic stimulation (TMS) technique, before the first session of EA (T0) and at the moment (T1), in 2 h (T2) and 24 h (T3) after the end of the last session of EA, on the left first dorsal interosseous muscle, the amplitude, latency (LAT), resting motor threshold (rMT) of motor evoked potentials (MEPs) and the completion time of grooved pegboard test (GPT) were detected. Besides, in the EA_6h group, TMS was adopted to detect the excitability of M1 (amplitude, LAT and rMT of MEPs) before the last session of EA (T0*). RESULTS: The amplitude of MEPs at T1 and T2 in the EA₀ group, at T0* in the EA_6h group and at T1, T2 and T3 in the EA_48h group was higher when compared with the value at T0 in each group separately (P<0.001). At T1, the amplitude of MEPs in the EA₀ group and the EA_48h group was higher than that in the EA_6h group (P<0.001, P<0.01); at T2, it was higher in the EA₀ group when compared with that in the EA_6h group (P<0.01); at T3, the amplitude in the EA₀ group and the EA_6h group was lower than that of the EA_48h group (P<0.001). The LAT at T1 was shorter than that at T0 in the three groups (P<0.05), and the changes were not obvious at the rest time points compared with that at T0 (P > 0.05). The GPT completion time of healthy subjects in the EA₀ group and the EA_48h group at T1, T2 and T3 was reduced in comparison with that at T0 (P<0.001). The completion time at T3 was shorter than that at T0 in the EA_6h group (P<0.05); at T2, it was reduced in the EA_48h group when compared with that of the EA_6h group (P<0.05). There were no significant differences in rMT among the three groups and within each group (P>0.05). CONCLUSIONS Under physiological conditions, EA has obvious after-effect on corticospinal excitability and upper limb motor function. The short-term interval protocol (6 h) blocks the after-effect of EA to a certain extent, while the long-term interval protocol (48 h) prolongs the after-effect of EA.
Humans ; Electroacupuncture ; Motor Cortex/physiology* ; Transcranial Magnetic Stimulation/methods* ; Upper Extremity ; Exercise ; Muscle, Skeletal/physiology*