Scalp acupuncture plus low-frequency rTMS promotes repair of brain white matter tracts in stroke patients: A DTI study

Repetitive transcranial magnetic stimulation for hypokinetic dysarthria in Parkinson's disease enhances white matter integrity of the auditory-motor loop

BACKGROUND AND PURPOSE

In our previous study, repeated sessions of repetitive transcranial magnetic stimulation (rTMS) over the auditory feedback area were shown to improve hypokinetic dysarthria (HD) in Parkinson's disease (PD) and led to changes in functional connectivity within the left-sided articulatory networks. We analyzed data from this previous study and assessed the effects of rTMS for HD in PD on the diffusion parameters of the left anterior arcuate fasciculus (AAF), which connects the auditory feedback area with motor regions involved in articulation.

METHODS

Patients were assigned to 10 sessions of real or sham 1-Hz stimulation over the right posterior superior temporal gyrus. Stimulation effects were evaluated using magnetic resonance diffusion tensor imaging and by a speech therapist using a validated tool (Phonetics score of the Dysarthric Profile) at baseline, immediately after 2 weeks of stimulation, and at follow-up visits at Weeks 6 and 10 after the baseline.

RESULTS

Altogether, data from 33 patients were analyzed. A linear mixed model revealed significant time-by-group interaction (p = 0.006) for the relative changes of fractional anisotropy of the AAF; the value increases were associated with the temporal evolution of the Phonetics score (R = 0.367, p = 0.028) in the real stimulation group.

CONCLUSIONS

Real rTMS treatment for HD in PD as compared to sham stimulation led to increases of white matter integrity of the auditory-motor loop during the 2-month follow-up period. The changes were related to motor speech improvements.

Acupuncture combined with repeated transcranial magnetic stimulation for upper limb motor function after stroke: A systematic review and meta-analysis

BACKGROUND

Upper limb motor dysfunction after stroke is an important factor affecting patients' motor function and daily life. Acupuncture and repetitive transcranial magnetic stimulation are effective methods for stroke rehabilitation. However, a systematic and comprehensive overview of the combined efficacy of the two is lacking.

OBJECTIVE

Through a systematic review and meta-analysis of randomized controlled trials, this study aimed to assess the effectiveness of acupuncture combined with repetitive transcranial magnetic stimulation on upper extremity motor function in post-stroke patients.

METHODS

The relevant randomized controlled trials on acupuncture combined with repetitive transcranial magnetic stimulation in the treatment of upper limb motor disorders after stroke were searched in PubMed, Embase, Cochrane Library, Web of Science CNKI, VIP, Wanfang, and CBM databases. After screening clinical trials that met the inclusion criteria, data extraction was conducted independently by two investigators. Meta-analysis was performed using RevMan 5.4 software.

RESULTS

After the screening, 18 articles were included, with a total of 1083 subjects. The results of meta-analysis showed that combination therapy could effectively improve the patients' upper limb motor function (MD = 7.77, 95%CI [6.32, 9.22], P < 0.05), ability of daily living (MD = 8.53, 95%CI [6.28, 10.79], P < 0.05), and hemiplegic shoulder pain (MD = - 1.72, 95%CI [- 2.26, - 1.18], P < 0.05). Meanwhile, for neurophysiological indexes, combined treatment could significantly shorten the latency of motor evoked potential and central motor conduction time (MD = - 1.42, 95%CI [- 2.14, - 0.71], P < 0.05); (MD = - 0.47, 95%CI [- 0.66, - 0.29], P < 0.05), and also could increase the amplitude of motor evoked potential (SMD = 0.71, 95%CI [0.28, 1.14], P < 0.05).

CONCLUSION

According to the results of the meta-analysis, we can conclude that acupuncture combined with repeated transcranial magnetic stimulation can significantly improve the upper limb motor function and daily living ability of stroke patients.

Insight Into the Effects of Clinical Repetitive Transcranial Magnetic Stimulation on the Brain From Positron Emission Tomography and Magnetic Resonance Imaging Studies: A Narrative Review

Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a therapeutic tool to alleviate symptoms for neurological and psychiatric diseases such as chronic pain, stroke, Parkinson’s disease, major depressive disorder, and others. Although the therapeutic potential of rTMS has been widely explored, the neurological basis of its effects is still not fully understood. Fortunately, the continuous development of imaging techniques has advanced our understanding of rTMS neurobiological underpinnings on the healthy and diseased brain. The objective of the current work is to summarize relevant findings from positron emission tomography (PET) and magnetic resonance imaging (MRI) techniques evaluating rTMS effects. We included studies that investigated the modulation of neurotransmission (evaluated with PET and magnetic resonance spectroscopy), brain activity (evaluated with PET), resting-state connectivity (evaluated with resting-state functional MRI), and microstructure (diffusion tensor imaging). Overall, results from imaging studies suggest that the effects of rTMS are complex and involve multiple neurotransmission systems, regions, and networks. The effects of stimulation seem to not only be dependent in the frequency used, but also in the participants characteristics such as disease progression. In patient populations, pre-stimulation evaluation was reported to predict responsiveness to stimulation, while post-stimulation neuroimaging measurements showed to be correlated with symptomatic improvement. These studies demonstrate the complexity of rTMS effects and highlight the relevance of imaging techniques.

Effect of Interactive Dynamic Scalp Acupuncture on Post-Stroke Cognitive Function, Depression, and Anxiety: A Multicenter, Randomized, Controlled Trial

OBJECTIVE

To compare the clinical effects of interactive dynamic scalp acupuncture (IDSA), simple combination therapy (SCT), and traditional scalp acupuncture (TSA) on cognitive function, depression and anxiety in patients with post-stroke cognitive impairment.

METHODS

A total of 660 patients with post-stroke cognitive impairment who were admitted to 3 hospitals in Shenzhen City between May 2017 and May 2020 were recruited and randomly assigned to the IDSA (218 cases), SCT (222 cases) and TSA groups (220 cases) according to a random number table. All the patients received conventional drug therapy for cerebral stroke and exercise rehabilitation training. Scalp acupuncture and computer-based cognitive training (CBCT) were performed simultaneously in the IDSA group, but separately in the morning and in the afternoon in the SCT group. The patients in the TSA group underwent scalp acupuncture only. The course of treatment was 8 weeks. Before treatment (M0), 1 (M1) and 2 months (M2) after treatment, as well as follow-up at 1 (M3) and 2 months (M4), the cognitive function of patients was assessed using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment Scale (MoCA) Scales; depression, anxiety, sleep quality, and self-care ability of patients were assessed using Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Rating Scale (HAMA), Pittsburgh Sleep Quality Index (PSQI), and Modified Barthel Index (MBI), respectively. During this trial, all adverse events (AEs) were accurately recorded.

RESULTS

There were no significant differences in the MMSE, MoCA, HAMD, HAMA, PSQI, and MBI scores among the 3 groups at M0 (all P>0.05). In the IDSA group, the MMSE, MoCA and MBI scores from M2 to M4 were significantly higher than those in the SCT and TSA groups, while the HAMD, HAMA and PSQI scores were significantly reduced (all P<0.01). The changes of all above scores (M2-M0, M4-M0) were significantly superior to those in the SCT and TSA groups (all P<0.01, except M4-M0 of HAMD). At M2, the severity of MMSE, HAMD, HAMA, PSQI and MBI in the IDSA group was significantly lower than that in the SCT and TSA groups (all P<0.01). There was no serious AE during this trial.

CONCLUSIONS

IDSA can not only significantly improve cognitive function, but also reduce depression, anxiety, which finally improves the patient's self-care ability. The effect of IDSA was significantly better than SCT and TSA. (Trial registration No. ChiCTR1900027206).

Effect of skin conductivity on the electric field induced by transcranial stimulation techniques in different head models

This study aims at quantifying the effect that using different skin conductivity values has on the estimation of the electric (E)-field distribution induced by transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) in the brain of two anatomical models. The induced E-field was calculated with numerical simulations inside MIDA and Duke models, assigning to the skin a conductivity value estimated from a multi-layered skin model and three values taken from literature. The effect of skin conductivity variations on the local E-field induced by tDCS in the brain was up to 70%. In TMS, minor local differences, in the order of 20%, were obtained in regions of interest for the onset of possible side effects. Results suggested that an accurate model of the skin is necessary in all numerical studies that aim at precisely estimating the E-field induced during TMS and tDCS applications. This also highlights the importance of further experimental studies on human skin characterization, especially at low frequencies.

Effect of different pulse numbers of transcranial magnetic stimulation on motor cortex excitability: Single-blind, randomized cross-over design

Aims

We aimed to investigate the effect of different pulse numbers of high‐frequency repetitive transcranial magnetic stimulation (rTMS) over the motor cortex on cortical excitability in healthy participants.

Methods

Fifteen healthy participants received 600 and 1200 pulses of 5‐Hz rTMS on separate days in a random order. Stimulation (duration, 2 seconds and interval, 1 seconds) was delivered over the left primary motor cortex for the hand, at 90% of resting motor threshold (rMT). The rMT and motor evoked potential (MEP) were measured before stimulation, and at 0 and 30 minutes after rTMS.

Results

No significant differences were observed between the two conditions for MEP (P = .919) or rMT (P = .266). Compared with baseline, MEP was increased significantly at 0 (P < .001) and 30 minutes (P < .001) after stimulation. After stimulation, rMT was decreased at 0 minute for the 600 and 1200 pulse conditions (P < .001), but had recovered by 30 minutes (P = .073).

Conclusion

Subthreshold 5‐Hz rTMS increased motor cortex excitability in healthy humans. However, the number of pulses may exhibit a ceiling effect in that beyond a certain point, that is, increasing the number of pulses may exhibit no further increase in cortical excitability.

Synergistic Effects of Scalp Acupuncture and Repetitive Transcranial Magnetic Stimulation on Cerebral Infarction: A Randomized Controlled Pilot Trial

This study investigated the synergistic effects of scalp acupuncture (SA) and repetitive transcranial magnetic stimulation (rTMS), known to be effective for cerebral infarction. This outcome-assessor-blinded, randomized controlled clinical trial included a per-protocol analysis to compare the efficacy of SA and electromagnetic convergence stimulation (SAEM-CS) and single or no stimulation. The trial was conducted with 42 cerebral infarction patients (control group, 12; SA group, 11; rTMS group, 8; SAEM-CS group, 11). All patient groups underwent two sessions of CSRT per day. SA, rTMS, and SAEM-CS were conducted once per day, 5 days per week, for 3 weeks. The primary outcome was evaluated using the Fugl–Mayer assessment (FMA). FMA Upper Extremity, FMA total, MBI, and FIM scores significantly increased in the rTMS group compared with the control group. Additionally, FMA Upper Extremity, FMA total, MBI and FIM scores significantly increased in the rTMS group compared with the SAEM-CS group. However, there were no significant changes in the SA or SAEM-CS groups. In conclusion, low-frequency rTMS in the contralesional hemisphere may have long-term therapeutic effects on upper extremity motor function recovery and improvements in activities of daily living. SAEM-CS did not show positive synergistic effects of SA and rTMS.

Diffusional plasticity induced by electroacupuncture intervention in rat model of peripheral nerve injury

Electroacupuncture (EA) is an adjuvant therapy for peripheral nerve injury (PNI). Both peripheral and central alterations contribute to the rehabilitation process. We employed diffusion tensor imaging (DTI) to investigate the diffusion plasticity of afferent and efferent pathways caused by EA in model of peripheral nerve injury and reparation. Twenty-four rats were divided into three groups: normal group, model group and intervention group. Rats of the model group and the intervention group underwent sciatic nerve transection and anastomosis. EA intervention was performed on the intervention group at ST-36 and GB-30 for three months. Gait assessment and DTI were conducted at days post-operative (DPO) 30, 60 and 90. We selected corticospinal tract, spinothalamic tract and internal capsule as regions of interest and analyzed diffusion metrics including fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD). FA values and RD values displayed significant differences or obvious tendency while AD values maintained a stable level. RD values displayed better indicative performance than FA in internal capsule. The intervention group presented significant correlation between RD values and Regularity Index (RI) during the intervention period. The effect of EA on peripheral nerve injury repairing rats appeared to be accelerated recovery process of sensory and motor neural pathway. We proposed that RD was a potential in vivo indicator for structural plasticity caused by EA and PNI.

The effect and optimal parameters of repetitive transcranial magnetic stimulation on motor recovery in stroke patients: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The primary aim of this meta-analysis was to evaluate the effects of repetitive transcranial magnetic stimulation (rTMS) on limb movement recovery post-stroke and cortex excitability, to explore the optimal parameters of rTMS and suitable stroke population. Second, adverse events were also included.

DATA SOURCES

The databases of PubMed, EBSCO, MEDLINE, the Cochrane Central Register of Controlled Trials, EBM Reviews-Cochrane Database, the Chinese National Knowledge Infrastructure, and the Chinese Science and Technology Journals Database were searched for randomized controlled trials exploring the effects of rTMS on limb motor function recovery post-stroke before December 2018.

REVIEW METHODS

The effect sizes of rTMS on limb motor recovery, the effect size of rTMS stimulation parameters, and different stroke population were summarized by calculating the standardized mean difference (SMD) and the 95% confidence interval using fixed/random effect models as appropriate.

RESULTS

For the motor function assessment, 42 eligible studies involving 1168 stroke patients were identified. The summary effect size indicated that rTMS had positive effects on limb motor recovery (SMD = 0.50, P < 0.00001) and activities of daily living (SMD = 0.82, P < 0.00001), and motor-evoked potentials of the stimulated hemisphere differed according to the stimulation frequency, that is, the high-frequency group (SMD = 0.57, P = 0.0006), except the low-frequency group (SMD = -0.27, P = 0.05). No significant differences were observed among the stimulation parameter subgroups except for the sessions subgroup ( P = 0.02). Only 10 included articles reported transient mild discomfort after rTMS.

CONCLUSIONS

rTMS promoted the recovery of limb motor function and changed the cortex excitability. rTMS may be better for early and pure subcortical stroke patients. Regarding different stimulation parameters, the number of stimulation sessions has an impact on the effect of rTMS.