Effects of transcranial magnetic stimulation on the cognitive event-related potential p300: a literature review

Efficacy of repetitive transcranial magnetic stimulation on post-stroke cognitive impairment: A systematic and a network meta-analysis

OBJECTIVES

This study aimed to evaluate the efficacy of different repetitive transcranial magnetic stimulation (rTMS) modes in stroke patients with cognitive impairment, and to rank the best option according to the outcome measures.

METHODS

Literature was searched in PubMed, Cochrane Library, Web of Science, Embase, SinoMed, China National Knowledge Infrastructure, Wanfang Database, and VIP Database, from database inception to September 2023. We included randomized controlled trials (RCTs) investigating the efficacy of all rTMS modes for post-stroke cognitive impairment. The selected studies assessed at least one of the following outcome measures: Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), P300 latency and amplitude, and modified Barthel Index (MBI) or BI. Two researchers independently conducted data extraction. Quality assessment was performed using RevMan 5.3 software based on the Cochrane Collaboration's tool, and statistical analysis was conducted by GeMTC 0.14.3 software and Stata 17.0 software.

RESULTS

The network meta-analysis included 74 RCTs with a total of 5478 patients. The best probability ranking indicated that intermittent theta burst stimulation (iTBS) was the most effective in enhancing MoCA, MMSE and MBI scores (85%, 54%, 42%, respectively), followed by 10 Hz rTMS (79%, 50%, 39%, respectively), for P300 amplitude, ≤1 Hz rTMS was ranked first (52%).

CONCLUSIONS

The current limited evidence suggests that iTBS may be the optimal approach for improving cognitive and daily life abilities of stroke patients, followed by 10 Hz rTMS, ≤1 Hz rTMS may be the preferred option for enhancing P300 amplitude.

TRAIL REGISTRATION

PROSPERO 2023 CRD42023424771 available from: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=424771.

Rapid improvements and subsequent effects in major depressive disorder patients with somatic pain using rTMS combined with sertraline

This study aims to explore changes in depression and pain for major depressive disorder (MDD) patients with somatic pain after repetitive transcranial magnetic stimulation (rTMS) using the event-related potentials (ERPs) technique. Eighty MDD patients with somatic pain were randomly assigned to drug therapy (DT) and combined therapy (CT) groups. CT group underwent intermittent theta burst stimulation over the left dorsolateral prefrontal cortex (DLPFC) with 800 pulses and 1 Hz over the right DLPFC with 800 pulses, 5 times a week for 3 weeks. All patients were given sertraline at 50-100 mg per day. All subjects were evaluated at baseline and at weeks three and six of therapy using the Hamilton Rating Scale for Depression (HAMD), Hamilton Anxiety Scale (HAMA), and Numerical Rating Scales (NRS), and the latency and amplitude of P300 and mismatch negativity (MMN) were measured. There were no significant differences in all indices between groups at baseline. At 3 weeks, HAMD subscale scores of Cognitive Impairment and NRS scores were significantly lower in the CT group than in the DT group. At 6 weeks, NRS and HAMD total scores in the CT group decreased significantly in the CT group compared with the DT group, especially for anxiety and pain, and the MMN and P300 latencies and P300 amplitude showed greater improvements. Our findings highlight that rTMS in combination with antidepressants is a rapid method of symptom improvement in patients with somatic pain with MDD and is helpful for cognitive impairment and anxiety.

Effects of excitatory transcranial magnetic stimulation over the different cerebral hemispheres dorsolateral prefrontal cortex for post-stroke cognitive impairment: a systematic review and meta-analysis

Background

Post-stroke cognitive impairment (PSCI) is a significant health concern. Transcranial magnetic stimulation (TMS) is considered a promising rehabilitation therapy for improving cognition, and the effects of excitatory TMS on PSCI have received much attention in recent years. However, the effects of different cerebral hemispheres on excitatory TMS treatment of cognitive impairment have not been studied. This review aimed to study the effects of excitatory TMS over the dorsolateral prefrontal cortex (DLPFC) of different cerebral hemispheres on the cognitive function of patients with PSCI.

Methods

Literature published in PubMed, Web of Science, Embase, Cochrane Library, Scopus, and Wiley from inception to September 30, 2022, were searched. Two researchers independently performed literature screening, data extraction, and quality assessment. Furthermore, we conducted a meta-analysis using RevMan software (version 5.4) and rated the strength of evidence using GRADEpro.

Results

A total of 19 studies were included in this meta-analysis. The results showed that excitatory TMS over the left hemisphere DLPFC was significantly better in improving global cognition (SMD = 2.26, 95% CI 1.67-2.86, P < 0.00001; vs. SMD = 2.53, 95% CI 1.86-3.20, P < 0.00001), memory (SMD = 1.29, 95% CI 0.72-1.87, P < 0.0001), attention (SMD = 2.32, 95% CI 1.64-3.01, P < 0.00001), executive (SMD = 0.64, 95% CI 0.21-1.07, P = 0.004), P300 latency (SMD = 2.69, 95% CI 2.13-3.25, P < 0.00001), and depression (SMD = 0.95, 95% CI 0.26-1.63, P = 0.007) than that of the control group, but the effect on improving activities of daily living (ADL) was unclear (P = 0.03 vs. P = 0.17). Subgroup analysis further showed that excitatory TMS over the right hemisphere DLPFC was effective in improving the global cognition of PSCI patients (P < 0.00001), but the stimulation effect over the ipsilateral hemisphere DLPFC was unclear (P = 0.11 vs. P = 0.003). Additionally, excitatory TMS over the ipsilateral hemisphere DLPFC showed no statistical difference in improving ADL between the two groups (P = 0.25).

Conclusions

Compared to other hemispheric sides, excitatory TMS over the left hemisphere DLPFC was a more effective stimulation area, which can significantly improved the global cognitive function, memory, attention, executive, P300 latency, and depression in patients with PSCI. There was no apparent therapeutic effect on improving activities of daily living (ADL). In the future, more randomized controlled trials with large-sample, high quality, and follow-up are necessary to explore a usable protocol further.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022369096.

Improvement of poststroke cognitive impairment by intermittent theta bursts: A double-blind randomized controlled trial

BACKGROUND

Intermittent theta burst stimulation (iTBS) is known to improve cognitive impairment caused by Alzheimer's disease and Parkinson's disease, but studies are lacking with respect to the efficacy of iTBS on poststroke cognitive impairment (PSCI).

OBJECTIVE

This study was conducted to investigate the effect of left dorsolateral prefrontal cortex (DLPFC) iTBS on improving cognitive function in stroke patients.

METHODS

Fifty-eight patients with PSCI are randomly divided into iTBS (n = 28) and sham stimulation groups (n = 30). Both groups receive routine cognitive-related rehabilitation. The iTBS group is treated with iTBS intervention of the left DLPFC, and the sham stimulation group is treated with the same parameters at the same site for 2 weeks. Outcome measures are assessed at baseline (T0) and immediately after the last intervention (T1) by mini-mental state examination (MMSE), Oxford cognitive screen, and event-related potential P300.

RESULTS

There are no differences in baseline clinical characteristics between the two groups. After intervention, the MMSE scores and P300 amplitude increase significantly for both groups, and the P300 incubation period reduces significantly. The change value of the iTBS group is significantly higher than that of sham stimulation group (p < .05). Compared with the sham stimulation group, the iTBS group has more significant changes in semantic comprehension and executive function (p < .05).

CONCLUSION

iTBS can effectively and safely improve overall cognitive impairment in stroke patients, including semantic understanding and executive function, and it also has a positive impact on memory function. Future randomized controlled studies with large samples and long-term follow-up should be conducted to further validate the results of the present study.

Treatment effects on event-related EEG potentials and oscillations in Alzheimer's disease

Alzheimer's disease dementia (ADD) is the most diffuse neurodegenerative disorder belonging to mild cognitive impairment (MCI) and dementia in old persons. This disease is provoked by an abnormal accumulation of amyloid-beta and tauopathy proteins in the brain. Very recently, the first disease-modifying drug has been licensed with reserve (i.e., Aducanumab). Therefore, there is a need to identify and use biomarkers probing the neurophysiological underpinnings of human cognitive functions to test the clinical efficacy of that drug. In this regard, event-related electroencephalographic potentials (ERPs) and oscillations (EROs) are promising candidates. Here, an Expert Panel from the Electrophysiology Professional Interest Area of the Alzheimer's Association and Global Brain Consortium reviewed the field literature on the effects of the most used symptomatic drug against ADD (i.e., Acetylcholinesterase inhibitors) on ERPs and EROs in ADD patients with MCI and dementia at the group level. The most convincing results were found in ADD patients. In those patients, Acetylcholinesterase inhibitors partially normalized ERP P300 peak latency and amplitude in oddball paradigms using visual stimuli. In these same paradigms, those drugs partially normalize ERO phase-locking at the theta band (4-7 Hz) and spectral coherence between electrode pairs at the gamma (around 40 Hz) band. These results are of great interest and may motivate multicentric, double-blind, randomized, and placebo-controlled clinical trials in MCI and ADD patients for final cross-validation.

Examining and Modulating Neural Circuits in Psychiatric Disorders With Transcranial Magnetic Stimulation and Electroencephalography: Present Practices and Future Developments

Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique uniquely equipped to both examine and modulate neural systems and related cognitive and behavioral functions in humans. As an examination tool, TMS can be used in combination with EEG (TMS-EEG) to elucidate directly, objectively, and noninvasively the intrinsic properties of a specific cortical region, including excitation, inhibition, reactivity, and oscillatory activity, irrespective of the individual's conscious effort. Additionally, when applied in repetitive patterns, TMS has been shown to modulate brain networks in healthy individuals, as well as ameliorate symptoms in individuals with psychiatric disorders. The key role of TMS in assessing and modulating neural dysfunctions and associated clinical and cognitive deficits in psychiatric populations is therefore becoming increasingly evident. In this article, the authors review TMS-EEG studies in schizophrenia and mood disorders, as most TMS-EEG studies to date have focused on individuals with these disorders. The authors present the evidence on the efficacy of repetitive TMS (rTMS) and theta burst stimulation (TBS), when targeting specific cortical areas, in modulating neural circuits and ameliorating symptoms and abnormal behaviors in individuals with psychiatric disorders, especially when informed by resting-state and task-related neuroimaging measures. Examples of how the combination of TMS-EEG assessments and rTMS and TBS paradigms can be utilized to both characterize and modulate neural circuit alterations in individuals with psychiatric disorders are also provided. This approach, along with the evaluation of the behavioral effects of TMS-related neuromodulation, has the potential to lead to the development of more effective and personalized interventions for individuals with psychiatric disorders.

Bilateral theta-burst magnetic stimulation influence on event-related brain potentials

Theta-burst stimulation (TBS) can be a non-invasive technique to modulate cognitive functions, with promising therapeutic potential, but with some contradictory results. Event related potentials are used as a marker of brain deterioration and can be used to evaluate TBS-related cognitive performance, but its use remains scant. This study aimed to study bilateral inhibitory and excitatory TBS effects upon neurocognitive performance of young healthy volunteers, using the auditory P300' results. Using a double-blind sham-controlled study, 51 healthy volunteers were randomly assigned to five different groups, two submitted to either excitatory (iTBS) or inhibitory (cTBS) stimulation over the left dorsolateral pre-frontal cortex (DLPFC), two other actively stimulated the right DLPFC and finally a sham stimulation group. An oddball based auditory P300 was performed just before a single session of iTBS, cTBS or sham stimulation and repeated immediately after. P300 mean latency comparison between the pre- and post-TBS stimulation stages revealed significantly faster post stimulation latencies only when iTBS was performed on the left hemisphere (p = 0.003). Right and left hemisphere cTBS significantly delayed P300 latency (right p = 0.026; left p = 0.000). Multiple comparisons for N200 showed slower latencies after iTBS over the right hemisphere. No significant difference was found in amplitude variation. TBS appears to effectively influence neural networking involved in P300 formation, but effects seem distinct for iTBS vs cTBS and for the right or the left hemisphere. P300 evoked potentials can be an effective and practical tool to evaluate transcranial magnetic stimulation related outcomes.

Characterizing and Modulating Brain Circuitry through Transcranial Magnetic Stimulation Combined with Electroencephalography

The concurrent combination of transcranial magnetic stimulation (TMS) with electroencephalography (TMS-EEG) is a powerful technology for characterizing and modulating brain networks across developmental, behavioral, and disease states. Given the global initiatives in mapping the human brain, recognition of the utility of this technique is growing across neuroscience disciplines. Importantly, TMS-EEG offers translational biomarkers that can be applied in health and disease, across the lifespan, and in humans and animals, bridging the gap between animal models and human studies. However, to utilize the full potential of TMS-EEG methodology, standardization of TMS-EEG study protocols is needed. In this article, we review the principles of TMS-EEG methodology, factors impacting TMS-EEG outcome measures, and the techniques for preventing and correcting artifacts in TMS-EEG data. To promote the standardization of this technique, we provide comprehensive guides for designing TMS-EEG studies and conducting TMS-EEG experiments. We conclude by reviewing the application of TMS-EEG in basic, cognitive and clinical neurosciences, and evaluate the potential of this emerging technology in brain research.

Cognitive effects of repetitive transcranial magnetic stimulation in patients with neurodegenerative diseases - clinician's perspective

Repetitive transcranial magnetic stimulation (rTMS) represents a promising tool for studying and influencing cognition in people with neurodegenerative diseases. This procedure is noninvasive and painless, and it does not require the use of anesthesia or pharmacological substances. In this systematic critical review we report outcomes from research focused on behavioral cognitive effects induced by rTMS in patients with Alzheimer's disease (AD), Parkinson's disease (PD), and mild cognitive impairment (MCI) preceding AD. There are still major limitations to rTMS use, such as a poor understanding of its after-effects and inter-individual variability in their magnitude, discrepancies in stimulation protocols and study designs, varied selection of the specific stimulated areas and control procedures, and neuropsychological methods for assessment of after-effects; hence, the results of the present research can only be considered preliminary. The future directions are discussed.