Behavioral Differences Across Theta Burst Stimulation Protocols. A Study on the Sense of Agency in Healthy Humans

BackgroundTheta burst stimulation (TBS) is a non-invasive brain stimulation method. Various stimulation protocols have been proposed, for instance, stimulation at 50 Hz with pattern at 5 Hz, or at 30 Hz with pattern at 6 Hz. To identify better stimulation parameters for behavioral applications, we investigated the effects of 50-Hz continuous TBS (cTBS) on the sense of agency (SoA), and compared them with a previously published study with 30-Hz cTBS.MethodsBased on power analysis from a previous sample using two applications of 30-Hz cTBS, we recruited 20 healthy subjects in a single-blind, Vertex-controlled, randomized, crossover trial. Participants were stimulated with one application of 50-Hz cTBS over the right posterior parietal cortex (rPPC), a key area for agency processing, and the vertex, in a random order. A behavioral task targeting the SoA was done before and after stimulation. After controlling for baseline differences across samples, we studied the effect of stimulation in the two protocols separately.ResultsCompared to the previously published 30-Hz protocol, 50-Hz cTBS over the rPPC did not reveal significant changes in the SoA, similar to sham Vertex stimulation.ConclusionOne application of 50-Hz cTBS was not sufficient to elicit behavioral effects, compared to two applications of 30-Hz cTBS, as previously described. This may be due to a mechanism of synaptic plasticity, consolidated through consecutive stimulation cycles. Our results are relevant for future studies aiming at modulating activity of the rPPC in cognitive domains other than agency, and in patients affected by abnormal agency, who could benefit from treatment options based on TBS.

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Therapeutic Use of Cerebellar Intermittent Theta Burst Stimulation (iTBS) in a Sardinian Family Affected by Spinocerebellar Ataxia 38 (SCA 38)

The Cerebellum ◽

10.1007/s12311-021-01313-z ◽

2021 ◽

Author(s):

Angela Sanna ◽

Paolo Follesa ◽

Paolo Tacconi ◽

Mariangela Serra ◽

Maria Giuseppina Pisu ◽

...

Keyword(s):

Spinocerebellar Ataxia ◽

Rating Scale ◽

Clinical Symptoms ◽

Therapeutic Use ◽

Theta Burst Stimulation ◽

Burst Stimulation ◽

Motor Cortex Excitability ◽

Before And After ◽

Theta Burst ◽

Serum Bdnf

AbstractSpinocerebellar ataxia 38 (SCA 38) is an autosomal dominant disorder caused by conventional mutations in the ELOVL5 gene which encodes an enzyme involved in the synthesis of very long fatty acids, with a specific expression in cerebellar Purkinje cells. Three Italian families carrying the mutation, one of which is of Sardinian descent, have been identified and characterized. One session of cerebellar intermittent theta burst stimulation (iTBS) was applied to 6 affected members of the Sardinian family to probe motor cortex excitability measured by motor-evoked potentials (MEPs). Afterwards, patients were exposed to ten sessions of cerebellar real and sham iTBS in a cross-over study and clinical symptoms were evaluated before and after treatment by Modified International Cooperative Ataxia Rating Scale (MICARS). Moreover, serum BDNF levels were evaluated before and after real and sham cerebellar iTBS and the role of BDNF Val66Met polymorphism in influencing iTBS effect was explored. Present data show that one session of cerebellar iTBS was able to increase MEPs in all tested patients, suggesting an enhancement of the cerebello-thalamo-cortical pathway in SCA 38. MICARS scores were reduced after ten sessions of real cerebellar iTBS showing an improvement in clinical symptoms. Finally, although serum BDNF levels were not affected by cerebellar iTBS when considering all samples, segregating for genotype a difference was found between Val66Val and Val66Met carriers. These preliminary data suggest a potential therapeutic use of cerebellar iTBS in improving motor symptoms of SCA38.

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Cerebellar Theta-Burst Stimulation Impairs Memory Consolidation in Eyeblink Classical Conditioning

Neural Plasticity ◽

10.1155/2018/6856475 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

Jessica Monaco ◽

Lorenzo Rocchi ◽

Francesca Ginatempo ◽

Egidio D'Angelo ◽

John C. Rothwell

Keyword(s):

Classical Conditioning ◽

Cerebellar Nuclei ◽

Cerebellar Hemisphere ◽

Theta Burst Stimulation ◽

Burst Stimulation ◽

Deep Cerebellar Nuclei ◽

Significant Impairment ◽

Conditioned Responses ◽

The Right ◽

Theta Burst

Associative learning of sensorimotor contingences, as it occurs in eyeblink classical conditioning (EBCC), is known to involve the cerebellum, but its mechanism remains controversial. EBCC involves a sequence of learning processes which are thought to occur in the cerebellar cortex and deep cerebellar nuclei. Recently, the extinction phase of EBCC has been shown to be modulated after one week by cerebellar continuous theta-burst stimulation (cTBS). Here, we asked whether cerebellar cTBS could affect retention and reacquisition of conditioned responses (CRs) tested immediately after conditioning. We also investigated a possible lateralized cerebellar control of EBCC by applying cTBS on both the right and left cerebellar hemispheres. Both right and left cerebellar cTBSs induced a statistically significant impairment in retention and new acquisition of conditioned responses (CRs), the disruption effect being marginally more effective when the left cerebellar hemisphere was stimulated. These data support a model in which cTBS impairs retention and reacquisition of CR in the cerebellum, possibly by interfering with the transfer of memory to the deep cerebellar nuclei.

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Effects of a single session of cathodal transcranial direct current stimulation primed intermittent theta-burst stimulation on heart rate variability and cortical excitability measures

Indian Journal of Physiology and Pharmacology ◽

10.25259/ijpp_339_2020 ◽

2021 ◽

Vol 65 ◽

pp. 162-166

Author(s):

B. N. Keerthy ◽

Sai Sreevalli Sarma Sreepada ◽

Shalini S. Naik ◽

Anushree Bose ◽

Raju Hanumegowda ◽

...

Keyword(s):

Healthy Volunteers ◽

Dorsolateral Prefrontal Cortex ◽

Cortical Excitability ◽

Single Session ◽

Theta Burst Stimulation ◽

Burst Stimulation ◽

Cathodal Tdcs ◽

Dorsolateral Prefrontal ◽

Before And After ◽

Theta Burst

Objectives: Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) have been used as neuromodulators in neuropsychiatric conditions. This study is aimed to find the effects of a single session of priming cathodal tDCS with intermittent theta-burst stimulation (iTBS) over left dorsolateral prefrontal cortex on heart rate variability (HRV) and cortical excitability parameters before and after perturbation. Materials and Methods: The neuromodulatory techniques used in the study were Cathodal tDCS for 20 min followed by iTBS for 3 min on the left dorsolateral prefrontal cortex (DLPFC). HRV variables and TMS parameters were recorded before and after this intervention of combined neuromodulation in 31 healthy volunteers (20 males and 11 females; age range of 19–35 years with Mean ± SD = 24.2 ± 4.7 years). Results: The results showed an overall increase in cortical excitability and parasympathetic dominance in healthy volunteers. Other measures of cortical excitability and HRV did not change significantly following single session of combined neuromodulation. Conclusion: This study showed that there is an overall increase in cortical excitability and parasympathetic dominance in the cohort of healthy volunteers following a combination of neuromodulation involving cathodal tDCS followed by iTBS over left DLPFC. Future studies exploring the effects of other possible combinations with sham stimulation could be carried out to explore the utility of dual stimulation as add-on therapy in disorders.

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Continuous theta-burst stimulation over the right dorsolateral prefrontal cortex impairs visuospatial working memory performance in medium load task

Neuroreport ◽

10.1097/wnr.0000000000001666 ◽

2021 ◽

Vol 32 (9) ◽

pp. 808-814

Author(s):

Ronald Ngetich ◽

Wenjuan Li ◽

Donggang Jin ◽

Junjun Zhang ◽

Zhenlan Jin ◽

...

Keyword(s):

Working Memory ◽

Dorsolateral Prefrontal Cortex ◽

Memory Performance ◽

Visuospatial Working Memory ◽

Theta Burst Stimulation ◽

Burst Stimulation ◽

Dorsolateral Prefrontal ◽

The Right ◽

Theta Burst ◽

Continuous Theta Burst Stimulation

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Effects of High-Definition Transcranial Direct Current Stimulation and Theta Burst Stimulation for Modulating the Posterior Parietal Cortex

Journal of the International Neuropsychological Society ◽

10.1017/s1355617719000766 ◽

2019 ◽

Vol 25 (09) ◽

pp. 972-984

Author(s):

Tian Gan ◽

Stevan Nikolin ◽

Colleen K. Loo ◽

Donel M. Martin

Keyword(s):

Working Memory ◽

Parietal Cortex ◽

Direct Current ◽

Posterior Parietal Cortex ◽

Theta Burst Stimulation ◽

Burst Stimulation ◽

High Definition ◽

Attention Task ◽

Posterior Parietal ◽

Theta Burst

AbstractObjectives:Noninvasive brain stimulation methods, including high-definition transcranial direct current stimulation (HD-tDCS) and theta burst stimulation (TBS) have emerged as novel tools to modulate and explore brain function. However, the relative efficacy of these newer stimulation approaches for modulating cognitive functioning remains unclear. This study investigated the cognitive effects of HD-tDCS, intermittent TBS (iTBS) and prolonged continuous TBS (ProcTBS) and explored the potential of these approaches for modulating hypothesized functions of the left posterior parietal cortex (PPC).Methods:Twenty-two healthy volunteers attended four experimental sessions in a cross-over experimental design. In each session, participants either received HD-tDCS, iTBS, ProcTBS or sham, and completed cognitive tasks, including a divided attention task, a working memory maintenance task and an attention task (emotional Stroop test).Results:The results showed that compared to sham, HD-tDCS, iTBS and ProcTBS caused significantly faster response times on the emotional Stroop task. The effect size (Cohen’sd) wasd= .32 for iTBS (p< .001), .21 for ProcTBS (p= .01) and .15 for HD-tDCS (p= .044). However, for the performance on the divided attention and working memory maintenance tasks, no significant effect of stimulation was found.Conclusions:The results suggest that repetitive transcranial magnetic stimulation techniques, including TBS, may have greater efficacy for modulating cognition compared with HD-tDCS, and extend existing knowledge about specific functions of the left PPC.

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Single Session Transcranial Magnetic Stimulation Ameliorates Hand Gesture Deficits in Schizophrenia

Schizophrenia Bulletin ◽

10.1093/schbul/sbz078 ◽

2019 ◽

Cited By ~ 2

Author(s):

Sebastian Walther ◽

Maribel Kunz ◽

Manuela Müller ◽

Caroline Zürcher ◽

Irena Vladimirova ◽

...

Keyword(s):

Transcranial Magnetic Stimulation ◽

Magnetic Stimulation ◽

Inferior Frontal Gyrus ◽

Manual Dexterity ◽

Secondary Outcome ◽

Hand Gesture ◽

Theta Burst Stimulation ◽

Burst Stimulation ◽

The Right ◽

Theta Burst

Abstract Social interaction is impaired in schizophrenia, including the use of hand gestures, which is linked to poor social perception and outcome. Brain imaging suggests reduced neural activity in a left-lateralized frontoparietal network during gesture preparation; therefore, gesturing might be improved through facilitation of left hemispheric brain areas or via disruption of interhemispheric inhibition from the right homolog. This study tested whether repetitive transcranial magnetic stimulation (rTMS) protocols would improve gesture performance in schizophrenia. This randomized, placebo-controlled, double-blind, crossover trial applied 3 different protocols of rTMS separated by 48 h. Twenty right-handed schizophrenia patients and 20 matched healthy controls received facilitatory intermittent theta burst stimulation (iTBS) over the left inferior frontal gyrus (IFG), inhibitory continuous theta burst stimulation (cTBS) over right inferior parietal lobe (IPL), and placebo over left IPL in randomized order. Primary outcome was change in the test of upper limb apraxia (TULIA), rated from video recordings of hand gesture performance. Secondary outcome was change in manual dexterity using the coin rotation task. Participants improved on both tasks following rTMS compared with baseline. Only patients improved gesture performance following right IPL cTBS compared with placebo (P = .013). The results of the coin rotation parallel those of the TULIA, with improvements following right IPL cTBS in patients (P = .001). Single sessions of cTBS on the right IPL substantially improved both gesture performance accuracy and manual dexterity. The findings point toward an inhibition of interhemispheric rivalry as a potential mechanism of action.

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Plasticity Induced by Intermittent Theta Burst Stimulation in Bilateral Motor Cortices Is Not Altered in Older Adults

Neural Plasticity ◽

10.1155/2015/323409 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 15

Author(s):

Daina S. E. Dickins ◽

Martin V. Sale ◽

Marc R. Kamke

Keyword(s):

Older Adults ◽

Cortical Excitability ◽

Motor Evoked Potentials ◽

Single Pulse ◽

Theta Burst Stimulation ◽

Burst Stimulation ◽

Motor Tasks ◽

Age Related ◽

Before And After ◽

Theta Burst

Numerous studies have reported that plasticity induced in the motor cortex by transcranial magnetic stimulation (TMS) is attenuated in older adults. Those investigations, however, have focused solely on the stimulated hemisphere. Compared to young adults, older adults exhibit more widespread activity across bilateral motor cortices during the performance of unilateral motor tasks, suggesting that the manifestation of plasticity might also be altered. To address this question, twenty young (<35 years old) and older adults (>65 years) underwent intermittent theta burst stimulation (iTBS) whilst attending to the hand targeted by the plasticity-inducing procedure. The amplitude of motor evoked potentials (MEPs) elicited by single pulse TMS was used to quantify cortical excitability before and after iTBS. Individual responses to iTBS were highly variable, with half the participants showing an unexpected decrease in cortical excitability. Contrary to predictions, however, there were no age-related differences in the magnitude or manifestation of plasticity across bilateral motor cortices. The findings suggest that advancing age does not influence the capacity for, or manifestation of, plasticity induced by iTBS.

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