scholarly journals Intermittent theta burst stimulation at personalized targets reduces the functional connectivity of the default mode network in healthy subjects

2019 ◽  
Author(s):  
Aditya Singh ◽  
Tracy Erwin-Grabner ◽  
Grant Sutcliffe ◽  
Walter Paulus ◽  
Peter Dechent ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Functional Connectivity ◽  
Default Mode Network ◽  
Healthy Subjects ◽  
Magnetic Stimulation ◽  
Anterior Cingulate ◽  
Single Session ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Theta Burst

AbstractUnderstanding the mechanisms by which transcranial magnetic stimulation protocols exert changes in the default mode network (DMN) is paramount to develop therapeutically more effective approaches in the future. A full session (3000 pulses) of 10 Hz repetitive transcranial magnetic stimulation (HF-rTMS) reduces the functional connectivity (FC) of the DMN and the subgenual anterior cingulate cortex but current understanding of the effects of a single session of intermittent theta burst stimulation (iTBS) on the DMN in healthy subjects is limited. To reduce the effects of inter-individual variability in functional architectures, we used a novel personalized target selection approach based on each subject’s resting state fMRI for an unprecedented investigation into the effects of a single session (1800 pulses) of iTBS over the DMN in healthy controls. 26 healthy subjects participated in a double-blind, crossover, sham-controlled study. After iTBS to the personalized left dorsolateral prefrontal cortex (DLPFC) targets, we investigated the time lapse of effects in the DMN and its relationship to the harm avoidance (HA) personality trait measure (Temperament and Character Inventory/TCI). Approx. 25-30 minutes after stimulation, we observed reduced FC between the DMN and the rostral anterior cingulate cortex (rACC). About 45 minutes after stimulation the FC of rACC strongly decreased further, as did the FC of right anterior insula (rAI) with the DMN. We also report a positive correlation between the FC decrease in the rACC and the HA domain of TCI. Our results show how iTBS at personalized left-DLPFC targets reduces the FC between DMN and the rACC and rAI, regions typically described as nodes of the salience network. We find that HA scores can potentially predict iTBS response, as has been observed for HF-rTMS.

The effects of 30 Hz, 50 Hz AND 100 Hz continuous theta burst stimulation via transcranial magnetic stimulation on the electrophysiological parameters in healthy individuals

2021 ◽  
Vol 74 (1-2) ◽  
pp. 41-49
Author(s):  
Zeynep Ozdemir ◽  
Erkan Acar ◽  
Aysun Soysal
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Short Interval ◽  
Motor Evoked Potential ◽  
Individual Variability ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Resting Motor Threshold ◽  
Theta Burst ◽  
Continuous Theta Burst Stimulation

Transcranial magnetic stimulation is a non-invasive procedure that uses robust magnetic fields to create an electrical current in the cerebral cortex. Dual stimulation consists of administering subthre­shold conditioning stimulation (CS), then suprathreshold test stimulation (TS). When the interstimulus interval (ISI) is 1-6 msec, the motor evoked potential (MEP) decreases in amplitude; this decrease is termed “short interval intracortical inhibition” (SICI); when the ISI is 7-30 msec, an increase in MEP amplitude occurs, termed “short interval intracortical facilitation” (SICF). Continuous theta burst stimulation (cTBS), often applied at a frequency of 50 Hz, has been shown to decrease cortical excitability. The primary objective is to determine which duration of cTBS achieves better inhibition or excitation. The secondary objective is to compare 50 Hz cTBS to 30 Hz and 100 Hz cTBS. The resting motor threshold (rMT), MEP, SICI, and SICF were studied in 30 healthy volunteers. CS and TS were administered at 80%-120% and 70%-140% of rMT at 2 and 3-millisecond (msec) intervals for SICI, and 10- and 12-msec intervals for SICF. Ten individuals in each group received 30, 50, or 100 Hz, followed by administration of rMT, MT-MEP, SICI, SICF immediately and at 30 minutes. Greater inhibition was achieved with 3 msec than 2 msec in SICI, whereas better facilitation occurred at 12 msec than 10 msec in SICF. At 30 Hz, cTBS augmented inhibition and suppressed facilitation, while 50 Hz yielded less inhibition and greater inter-individual variability. At 100 Hz, cTBS provided slight facilitation in MEP amplitudes with less interindividual variability. SICI and SICF did not differ significantly between 50 Hz and 100 Hz cTBS. Our results suggest that performing SICI and SICF for 3 and 12 msec, respectively, and CS and TS at 80%-120% of rMT, demonstrate safer inhibition and facilitation. Recently, TBS has been used in the treatment of various neurological diseases, and we recommend preferentially 30 Hz over 50 Hz cTBS for better inhibition with greater safety and less inter-individual variability.

scholarly journals Single Session Transcranial Magnetic Stimulation Ameliorates Hand Gesture Deficits in Schizophrenia

2019 ◽  
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.

scholarly journals Effects of low-frequency repetitive transcranial magnetic stimulation combined with cerebellar continuous theta burst stimulation on spasticity and limb dyskinesia in patients with stroke

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dawei Li ◽  
Aixia Cheng ◽  
Zhiyou Zhang ◽  
Yuqian Sun ◽  
Yingchun Liu
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Low Frequency ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Stroke Patients ◽  
Muscle Spasticity ◽  
Theta Burst ◽  
Continuous Theta Burst Stimulation

Abstract Background Repetitive transcranial magnetic stimulation (rTMS) has been reported to treat muscle spasticity in post-stroke patients. The purpose of this study was to explore whether combined low-frequency rTMS (LF-rTMS) and cerebellar continuous theta burst stimulation (cTBS) could provide better relief than different modalities alone for muscle spasticity and limb dyskinesia in stroke patients. Methods This study recruited ninety stroke patients with hemiplegia, who were divided into LF-rTMS+cTBS group (n=30), LF-rTMS group (n=30) and cTBS group (three pulse bursts at 50 Hz, n=30). The LF-rTMS group received 1 Hz rTMS stimulation of the motor cortical (M1) region on the unaffected side of the brain, the cTBS group received cTBS stimulation to the cerebellar region, and the LF-rTMS+cTBS group received 2 stimuli as described above. Each group received 4 weeks of stimulation followed by rehabilitation. Muscle spasticity, motor function of limb and activity of daily living (ADL) were evaluated by modified Ashworth Scale (MAS), Fugl-Meyer Assessment (FMA) and Modified Barthel Index (MBI) scores, respectively. Results The MAS score was markedly decreased, FMA and MBI scores were markedly increased in the three groups after therapy than before therapy. In addition, after therapy, LF-rTMS+cTBS group showed lower MAS score, higher FMA and MBI scores than the LF-rTMS group and cTBS group. Conclusion Muscle spasticity and limb dyskinesia of the three groups are all significantly improved after therapy. Combined LF-rTMS and cTBS treatment is more effective in improving muscle spasticity and limb dyskinesia of patients after stroke than LF-rTMS and cTBS treatment alone.

scholarly journals Comparison of the Effect of Low-Frequency Repetitive Transcranial Magnetic Stimulation with That of Theta Burst Stimulation on Upper Limb Motor Function in Poststroke Patients

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Takahiro Kondo ◽  
Naoki Yamada ◽  
Ryo Momosaki ◽  
Masato Shimizu ◽  
Masahiro Abo
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Function ◽  
Upper Limb ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Low Frequency ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Performance Time ◽  
Theta Burst

Background. The purpose of this study was to evaluate the difference between the therapeutic effect of low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) and that of continuous theta burst stimulation (cTBS), when each is combined with intensive occupational therapy (OT), in poststroke patients with upper limb hemiparesis. Materials and Methods. The study subjects were 103 poststroke patients with upper limb hemiparesis, who were divided into two groups: the LF-rTMS group (n=71) and the cTBS group (three pulse bursts at 50 Hz) (n=32). Each subject received 12 sessions of repetitive transcranial magnetic stimulation of 2,400 pulses applied to the nonlesional hemisphere and 240-min intensive OT (two 60-min one-to-one training sessions and two 60-min self-training exercises) daily for 15 days. Motor function was evaluated using the Fugl-Meyer Assessment (FMA) and the performance time of the Wolf motor function test (WMFT) was determined on the days of admission and discharge. Results. Both groups showed a significant increase in the FMA score and a short log performance time of the WMFT (p<0.001), but the increase in the FMA score was higher in the LF-rTMS group than the cTBS group (p<0.05). Conclusion. We recommend the use of 2400 pulses of LF-rTMS/OT for 2 weeks as treatment for hemiparetic patients.

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