Effects Of Low-frequency rTMS Research Articles

The effect of low-frequency rTMS on auditory hallucinations, EEG source localization and functional connectivity in schizophrenia

BackgroundLow-frequency repetitive transcranial magnetic stimulation (LF-rTMS) diminishes auditory hallucinations (AHs). The aims of our study were a) to assess the efficacy of LF-rTMS in a randomized, sham-controlled double-blind alignment, b) to identify the electrophysiological changes accompanying the LF-rTMS, and c) to identify the influence of LF-rTMS on brain functional connectivity (FC). MethodsNineteen schizophrenia patients with antipsychotic-resistant AHs were randomized to either active (n = 10) or sham (n = 9) LF-rTMS administered over the left temporo-parietal region for ten days. The clinical effect was assessed by the Auditory Hallucination Rating Scale (AHRS). The localization of the differences in electrical activity was identified by standardized low resolution brain electromagnetic tomography (sLORETA) and FC was measured by lagged phase synchronization. ResultsAHRS scores were significantly improved for patients receiving active rTMS compared to the sham (median reduction: 40 % vs 12 %; p = 0.01). sLORETA revealed a decrease of alpha-2, beta-1,-2 bands in the left hemisphere in the active group. Active rTMS led to a decrease of the lagged phase connectivity in beta bands originating in areas close to the site of stimulation, and to a prevailing increase of alpha-2 FC. No significant differences in current density or FC were observed in the sham group. LimitationsLimitations to our study included the small group sizes, and the disability of LORETA to assess subcortical neuronal activity. ConclusionsLF-rTMS attenuated AHs and induced a decrease of higher frequency bands on the left hemisphere. The FC changes support the assumption that LF-rTMS is linked to the modulation of cortico-cortical coupling.

Effects of repetitive transcranial magnetic stimulation over right dorsolateral prefrontal cortex on excessive daytime sleepiness in patients with Parkinson's disease

BackgroundExcessive daytime sleepiness (EDS) is a common sleep disorder in Parkinson's disease (PD), which seriously affects patients' quality of life. Repetitive transcranial magnetic stimulation (rTMS) can be used as an add-on therapy to a variety of non-motor symptoms of PD. However, little is known on the treatment of EDS in PD patients. ObjectiveTo explore the effects of low frequency rTMS over right dorsolateral prefrontal cortex (DLPFC) in the treatment of EDS in PD. MethodsWe conducted a sham-controlled, parallel study including 25 individuals of PD with possible EDS based on Epworth Sleepiness Scale (ESS ≥8 points) and randomly divided them into active group (n = 15) and sham group (n = 10). 1 Hz rTMS was administrated over right DLPFC for 10 consecutive days. In the active group, we further classified them into responsive group and non-responsive group according to change of ESS score in comparison with baseline. Clinical assessments on motor and non-motor symptoms were completed at baseline, at the end of treatment and 1 month after treatment. ResultsCompared to baseline, active group showed significant improvement on ESS score 10 days and 1 month after treatment (P < 0.05 for both). The percentage change of ESS score was positively related to disease duration during follow-up. No significant changes were observed on ESS score change in the sham group. Further analysis of individuals in the active group showed that, relative to those with non-response to rTMS, individuals with therapeutic response exhibited longer disease duration and lower baseline levodopa equivalent dose. ConclusionLow frequency rTMS over right DLPFC may improve symptoms of EDS in PD.

Effects of high frequency rTMS of contralesional dorsal premotor cortex in severe subcortical chronic stroke: protocol of a randomized controlled trial with multimodal neuroimaging assessments

BackgroundPrevious studies have revealed that low frequency repeated transcranial magnetic stimulation (rTMS) on the contralesional primary motor cortex (cM1) is less effective in severe stroke patients with poor neural structural reserve than in patients with highly reserved descending motor pathway. This may be attributed to the fact that secondary motor cortex, especially contralesional dorsal premotor cortex (cPMd), might play an important compensatory role in the motor function recovery of severely affected upper extremity. The main purpose of this study is to compare the effectiveness of low frequency rTMS on cM1 and high frequency rTMS on cPMd in subcortical chronic stroke patients with severe hemiplegia. By longitudinal analysis of multimodal neuroimaging data, we hope to elucidate the possible mechanism of brain reorganization following different treatment regimens of rTMS therapy, and to determine the cut-off of stimulation strategy selection based on the degree of neural structural reserve.Methods/designThe study will be a single-blinded randomized controlled trial involving a total of 60 subcortical chronic stroke patients with severe upper limb motor impairments. All patients will receive 3 weeks of conventional rehabilitation treatment, while they will be divided into three groups and receive different rTMS treatments: cM1 low frequency rTMS (n = 20), cPMd high frequency rTMS (n = 20), and sham stimulation group (n = 20). Clinical functional assessment, multimodal functional MRI (fMRI) scanning, and electrophysiological measurement will be performed before intervention, 3 weeks after intervention, and 4 weeks after the treatment, respectively.DiscussionThis will be the first study to compare the effects of low-frequency rTMS of cM1 and high-frequency rTMS of cPMd. The outcome of this study will provide a theoretical basis for clarifying the bimodal balance-recovery model of stroke, and provide a strategy for individualized rTMS treatment for stroke in future studies and clinical practice.Trial registrationChinese Clinical Trial Registry, ChiCTR1900027399. Registered on 12 Nov 2019, http://www.chictr.org.cn/showproj.aspx?proj=43686.

Effects of Low Frequency RTMS Combined with Rehabilitation Nursing on Lower Limb Spasm and Functional Rehabilitation of Stroke Patients

Effects of Low Frequency RTMS Combined with Rehabilitation Nursing on Lower Limb Spasm and Functional Rehabilitation of Stroke Patients

LF-rTMS ameliorates social dysfunction of FMR1−/− mice via modulating Akt/GSK-3β signaling

Autism spectrum disorders (ASD) are a group of neurological disorders which affect approximately 1% of children around the world. Social dysfunction is one of the two core syndromes of ASD, and still lacks effective treatment. Transcranial magnetic stimulation (TMS) is a noninvasive and safe procedure that uses magnetic fields to modulate neural activity. Whether it were effective in modulating social function remains unclear. By using 3-chamber test, ultrasonic vocalization recording and Western-blotting, we demonstrated that FMR1 (fragile X mental retardation protein) mutant mice, a model of ASD, exhibited obvious defects in social preference and ultrasonic communication. In addition, we detected increase of p-Akt (S473) and p-GSK-3β (S9), and decrease of p-PSD-95 (T19) in the anterior cingulate cortex (ACC) of FMR1−/− mice. Treating FMR1−/− mice with 1 Hz repetitive TMS (rTMS) exerted a long lasting effect in improving both the ultrasonic communication and social preference, as well as restoring the levels of Akt/GSK-3β activity and spine density in the FMR1−/−ACC. Our data, for the first time, demonstrated a beneficial effect of low frequency rTMS (LF-rTMS) on the social function of FMR1−/− mice and an involvement of Akt/GSK-3β signaling in this process, indicating LF-rTMS as a potential therapeutic strategy for ASD patients.

Effect of Low-Frequency rTMS and Intensive Speech Therapy Treatment on Patients With Nonfluent Aphasia After Stroke.

To observe the effect of low-frequency repetitive transcranial magnetic stimulation (rTMS) on patients with nonfluent aphasia after stroke. Thirty patients were divided into control, rTMS, and 2 times a day low-frequency rTMS (2rTMS) groups, and all 3 groups had intensive speech therapy (ST). Patients were assessed by western aphasia battery (WAB) scale. The spontaneous language, listening comprehension, retelling, and naming were scored, respectively. The expression of brain-derived neurotrophic factor (BDNF) in peripheral blood was detected by enzyme-linked immunosorbent assay. There was significant difference in aphasia quotient after treatment in the 3 groups. The values of the 4 dimensions in the WAB score of the rTMS group were higher than those in the control group. The WAB scores in the 2rTMS group were higher than those in the rTMS group. After 2 weeks treatment, the BDNF levels in the rTMS group and the 2rTMS group were significantly higher than those in the control group. Four weeks later, the 2rTMS group was significantly increased compared with the control group and the rTMS group. Low-frequency rTMS combined with conventional ST treatment can effectively improve the language function of patients with nonfluent aphasia after stroke. Two times a day low-frequency rTMS therapy combined with conventional ST treatment can improve the language function of patients with nonfluent aphasia after stroke more effectively and it also promote the expression of BDNF more effectively, thereby improving nerve repair and protecting brain tissue.

Repetitive transcranial magnetic stimulation of the prefrontal cortex for fibromyalgia syndrome: a randomised controlled trial with 6-months follow up

ObjectivesFibromyalgia Syndrome (FMS), is a chronic pain disorder with poorly understood pathophysiology. In recent years, repetitive transcranial magnetic stimulation (rTMS) has been recommended for pain relief in various chronic pain disorders. The objective of the present research was to study the effect of low frequency rTMS over the right dorsolateral prefrontal cortex (DLPFC) on pain status in FMS.MethodsNinety diagnosed cases of FMS were randomized into Sham-rTMS and Real-rTMS groups. Real rTMS (1 Hz/1200 pulses/8 trains/90% resting motor threshold) was delivered over the right DLPFC for 5 consecutive days/week for 4 weeks. Pain was assessed by subjective and objective methods along with oxidative stress markers. Patients were followed up for 6 months (post-rTMS;15 days, 3 months and 6 months).ResultsIn Real-rTMS group, average pain ratings and associated symptoms showed significant improvement post rTMS. The beneficial effects of rTMS lasted up to 6 months in the follow-up phase. In Sham-rTMS group, no significant change in pain ratings was observed.ConclusionRight DLPFC rTMS can significantly reduce pain and associated symptoms of FMS probably through targeting spinal pain circuits and top-down pain modulation .Trial registration: Ref No: CTRI/2013/12/004228.

T24. The effects of low-frequency repetitive transcranial magnetic stimulation on the local field potentials of hippocampus in rats

Repeated transcranial magnetic stimulation (rTMS), as a non-invasive brain stimulation technique, has been widely used applied in the field of neurology, psychology, rehabilitation. Previous studies have shown that low frequency rTMS have good anti-epilepsy effects, but its mechanism is not fully understood. We used the multi-channel in vivo recording technique to observe the effects of low frequency rTMS on the local field potential (LFPs) of rats hippocampal, and investigate the electrophysiological mechanism of low frequency rTMS in anti-epilepsy. Sprague-Dawley rats were randomly divided into rTMS group, control group and sham group, respectively variously treating with 500 pulses of 0.5 Hz rTMS for continuous 7 days. After last stimulation, LFPs of hippocampus were measured 20 min under anesthesia, then pilocarpine induced-epileptic seizures and recorded LFPs of hippocampus to 1 h after Status epilepticus (SE). LFPs was respectively partitioned using the common physiological frequency bands: delta (0.5–3.5 Hz), theta (4–7 Hz), gamma (30–80 Hz) and ripple (100–250 Hz), both was estimated with spectrum analysis and power spectral density. The results of spectrum analysis showed that compared with control group and sham group, low-frequency rTMS markedly increased spectrum energy and the power spectral density of delta, theta and gamma-band and significantly decreased the value of ripple oscillation (P < 0.05), while no significant difference between control group and sham group. In addition, low-frequency rTMS decreased the proportion of Racine stage 4–5 seizures, extended the period of latency until seizure onset, and significantly restrained the hippocampal ripple activities after seizures (p < 0.05). These results indicate that rTMS has a modulatory effect on the LFPs of hippocampus. The power of basal delta, theta and gamma-band oscillations in response to Low-frequency rTMS may reduce the excitability of hippocampal in normal rats, and it may be associated with the suppression of the pilocarpine induced-seizure activities.

EEG under TMS-induced SP reveals inhibitory effects of low-frequency rTMS on the primary motor cortex

EEG under TMS-induced SP reveals inhibitory effects of low-frequency rTMS on the primary motor cortex

Effects of low-frequency rTMS of the unaffected hemisphere in chronic stroke: a concomitant TMS and fMRI study

Effects of low-frequency rTMS of the unaffected hemisphere in chronic stroke: a concomitant TMS and fMRI study

RTMS and disorders of the motor system

Recent guidelines of the IFCN (Lefaucheur et al., 2014) on the therapeutic use of rTMS list the are variety of diseases. Here the focus will be laid on movement disorders, stroke and ALS. No recommendation for the antiparkinsonian effect can be made for high frequency (HF) or low frequency (LF) rTMS of the hand representation in M1 and for HF rTMS of the SMA. Only a possible antiparkinsonian effect of HF rTMS of bilateral (multiple) sites in M1 (Level C) emerged from this meta-analysis. A probable antidepressant effect of HF rTMS of the left DLPFC in Parkinson’s disease (Level B) emerged from the literature analysis. In motor stroke a possible effect of LF rTMS of the contralesional motor cortex in (post-)acute motor stroke (Level C) and a probable effect of LF rTMS of the contralesional motor cortex in chronic motor stroke (Level B) emerged. Ipsilesional stimulation revealed only possible effects of HF rTMS of the ipsilesional motor cortex in (post-)acute motor stroke and of HF rTMS of the ipsilesional motor cortex in chronic motor stroke (Level C). No recommendation can be made for ALS. Possible pitfalls for negative studies are mentioned combined with suggestions for improved study designs.

Crossed inhibition of sensory cortex by 0.3 Hz transcranial magnetic stimulation of motor cortex.

Low-frequency repetitive transcranial magnetic stimulation (rTMS) of motor cortex causes persistent inhibitory effects in the targeted area. rTMS of motor cortex impairs sensory perception and results in a persistent change in cortical function at remote sites. The ability of rTMS to induce sustained changes in cortical function has led to studies testing its therapeutic efficacy in neurologic disorders, including epilepsy. Studies on the effect of low-frequency rTMS of motor cortex on the contralateral motor cortex have provided evidence for both inhibitory and excitatory changes. This study was designed to determine the effect of low-frequency rTMS of the right motor cortex on the contralateral sensory cortex. Before and after 0.3-Hz rTMS of right motor cortex, perception of ipsilateral threshold of cutaneous stimuli was assessed and somatosensory evoked potentials (SEPs) recorded after stimulation of the right thumb in eight normal subjects. In a control group of six subjects, sensory responses were assessed after rTMS anterior to the right motor cortex. After rTMS of motor cortex, detection of threshold sensory stimuli decreased by more than 50% compared with pre-rTMS (P < 0.05). The change in sensory perception lasted at least 30 minutes. No change was detected in the control group. Amplitude of the N20-P25 waveform of the SEP decreased from a mean of 0.84 muV before rTMS to 0.54 muV immediately after rTMS of motor cortex (P < 0.05). 0.3 Hz rTMS of motor cortex inhibits the contralateral sensory cortex.

Inhibition of the primary motor cortex can alter one's “sense of effort”: Effects of low-frequency rTMS

Studies using force-matching tasks have suggested that when we feel a “sense of effort,” cortical regions may act to increase motor commands, and thus recruit additional motor units, in order to compensate for the exerted force. We hypothesized that suppressing activity in the primary motor cortex (M1), which is the source of the motor commands, would initiate the same process, and induce the same sense of effort. In a force-matching task, grip force was applied to ‘right’ hand and 10 healthy participants were asked to try to exert the same amount by using ‘left’ hand, with no visual feedback. On some trials, low-frequency, repetitive transcranial magnetic stimulation (lf-rTMS) was used to suppress the M1 and the primary somatosensory cortex (SI) in the left hemisphere, separately. Results showed that participants tended to overestimate the level of exerted force by up to 24%. In contrast, sham stimulation of the M1 and lf-rTMS over the SI did not significantly affect participants’ estimations. Further, the M1 suppression resulted in a 42% reduction in motor-evoked potentials. Thus, the M1 suppression can affect our sense of effort, suggesting that compensatory neural mechanisms that increase the MI activity may play an important role in producing senses of effort.

Effect of low frequency rTMS on stiffness of joints of the upper limbs in hemiplegic patients

Effect of low frequency rTMS on stiffness of joints of the upper limbs in hemiplegic patients

P721: Pre-treatment frontal quantitative EEG asymmetry as a predictor of antidepressant effects of low frequency rTMS in patients with major depression

P721: Pre-treatment frontal quantitative EEG asymmetry as a predictor of antidepressant effects of low frequency rTMS in patients with major depression

Effect of Low-Frequency rTMS and NMES on Subacute Unilateral Hemispheric Stroke With Dysphagia

ObjectiveTo investigate the effect of low-frequency repetitive transcranial magnetic stimulation (rTMS) and neuromuscular electrical stimulation (NMES) on post-stroke dysphagia.MethodsSubacute (<3 months), unilateral hemispheric stroke patients with dysphagia were randomly assigned to the conventional dysphagia therapy (CDT), rTMS, or NMES groups. In rTMS group, rTMS was performed at 100% resting motor threshold with 1 Hz frequency for 20 minutes per session (5 days per week for 2 weeks). In NMES group, electrical stimulation was applied to the anterior neck for 30 minutes per session (5 days per week for 2 weeks). All three groups were given conventional dysphagia therapy for 4 weeks. We evaluated the functional dysphagia scale (FDS), pharyngeal transit time (PTT), the penetration-aspiration scale (PAS), and the American Speech-Language Hearing Association National Outcomes Measurement System (ASHA NOMS) swallowing scale at baseline, after 2 weeks, and after 4 weeks.ResultsForty-seven patients completed the study; 15 in the CDT group, 14 in the rTMS group, and 18 in the NMES group. Mean changes in FDS and PAS for liquid during first 2 weeks in the rTMS and NMES groups were significantly higher than those in the CDT group, but no significant differences were found between the rTMS and NMES group. No significant difference in mean changes of FDS and PAS for semi-solid, PTT, and ASHA NOMS was observed among the three groups.ConclusionThese results indicated that both low-frequency rTMS and NMES could induce early recovery from dysphagia; therefore, they both could be useful therapeutic options for dysphagic stroke patients.

Repetitive transcranial magnetic stimulation decreases the kindling induced synaptic potentiation: Effects of frequency and coil shape

The present study was aimed to investigate the effects of repetitive transcranial magnetic stimulation (rTMS) on kindling-induced synaptic potentiation and to study the effect of frequency and coil shape on rTMS effectiveness. Seizures were induced in rats by perforant path stimulation in a rapid kindling manner (12 stimulations/day). rTMS was applied at different frequencies (0.5, 1 and 2 Hz), using either figure-8 shaped or circular coils at different times (during or before kindling stimulations). rTMS had antiepileptogenic effect at all frequencies and imposed inhibitory effects on enhancement of population excitatory postsynaptic potential slope and population spike amplitude when applied during kindling acquisition. Furthermore, it prevented the kindling-induced changes in paired pulse indices. The inhibitory effect of rTMS was higher at the frequency of 1 Hz compared to 0.5 and 2 Hz. Application of rTMS 1Hz by circular coil imposed a weaker inhibitory action compared with the figure-8 coil. In addition, the results showed that pretreatment of animals by both coils had similar preventing effect on kindling acquisition as well as kindling-induced synaptic potentiation. Obtained results demonstrated that the antiepileptogenic effect of low frequency rTMS is accompanied with the preventing of the kindling induced potentiation. This effect is dependent on rTMS frequency and slightly on coil-type.

RTMS in the management of auditory hallucinations in patients with schizophrenia.

rTMS in the management of auditory hallucinations in patients with schizophrenia.

Behavioral and neuroplastic effects of low-frequency rTMS of the unaffected hemisphere in a chronic stroke patient: A concomitant TMS and fMRI study

Repetitive Transcranial Magnetic Stimulation (rTMS) ameliorates motor and neuropsychological deficits following stroke, but little is known about the underlying neuroplasticity. We investigated neuroplastic changes following 5 days of low-frequency rTMS on the intact motor cortex to promote motor recovery in a chronic patient with subcortical stroke. The feasibility of administering multiple treatments was also assessed 6 months later by applying the same protocol over the patient’s parietal cortex to improve visuospatial disorders. Behavioral improvements and no adverse events were observed. Neuroimaging findings indicated that motor symptoms amelioration was associated with downregulation and cortical reorganization of hyperactive contralesional hemisphere.

The application of low frequency repetitive transcranial magnetic stimulation in rehabilitation of Parkinson's disease patients

Objective To explore the application value of low frequency repetitive transcranial magnetic stimulation (rTMS) in Parkinson's disease (PD) patients and electrophysiological research. Methods Fifty-six PD patients treated in the Department of Neurology of our hospital from September 2010 to September 2012 were randomly divided into 2 groups, group A (N = 28) and group B (N = 28). Patients in group A were given conventional drug treatment and rehabilitation training, while patients in group B were given low frequency rTMS on the basis of conventional drug treatment and rehabilitation training. After 3 weeks, the scores of Unified Parkinson's Disease Rating Scale (UPDRS), resting threshold (RT), cortical latent period, nerve root latent period, central motor conduction time (CMCT) and the incidence of adverse reactions were compared between 2 groups. Results After intervention, the emotion, ability of daily living and motor function of patients in group B was obviously improved, and the scores of UPDRS in group B were significantly lower than that in group A ( P 0.05). Conclusion The effect of low frequency rTMS in the treatment for PD is evident, safe and reliable, and with less adverse reaction. It can be used as a noninvasive physical treatment measure for PD.