title: Use of theta-burst stimulation in changing excitability of motor cortex: A systematic review and meta-analysis.
abstract: Noninvasive brain stimulation has been demonstrated to modulate cortical activity in humans. In particular, theta burst stimulation (TBS) has gained notable attention due to its ability to induce lasting physiological changes after short stimulation durations. The present study aimed to provide a comprehensive meta-analytic review of the efficacy of two TBS paradigms; intermittent (iTBS) and continuous (cTBS), on corticospinal excitability in healthy individuals. Literature searches yielded a total of 87 studies adhering to the inclusion criteria. iTBS yielded moderately large MEP increases lasting up to 30 min with a pooled SMD of 0.71 (p<0.00001). cTBS produced a reduction in MEP amplitudes lasting up to 60 min, with the largest effect size seen at 5 min post stimulation (SMD=-0.9, P<0.00001). The collected studies were of heterogeneous nature, and a series of tests conducted indicated a degree of publication bias. No significant change in SICI and ICF was observed, with exception to decrease in SICI with cTBS at the early time point (SMD=0.42, P=0.00036). The results also highlight several factors contributing to TBS efficacy, including the number of pulses, frequency of stimulation and BDNF polymorphisms. Further research investigating optimal TBS stimulation parameters, particularly for iTBS, is needed in order for these paradigms to be successfully translated into clinical settings.
authors: Monash Alfred Psychiatry Research Centre, Central Clinical School, The Alfred and Monash University, Melbourne, Australia. Electronic address: sung.chung@monash.edu.
authors: Sung Wook
authors: SW
authors: Chung
authors: Monash Alfred Psychiatry Research Centre, Central Clinical School, The Alfred and Monash University, Melbourne, Australia.
authors: Aron T
authors: AT
authors: Hill
authors: Brain and Mental Health Laboratory, School of Psychological Sciences and Monash Biomedical Imaging, Monash University, Melbourne, Australia.
authors: Nigel C
authors: NC
authors: Rogasch
authors: Monash Alfred Psychiatry Research Centre, Central Clinical School, The Alfred and Monash University, Melbourne, Australia.
authors: Kate E
authors: KE
authors: Hoy
authors: Monash Alfred Psychiatry Research Centre, Central Clinical School, The Alfred and Monash University, Melbourne, Australia.
authors: Paul B
authors: PB
authors: Fitzgerald
mesh_terms: D000328:Adult; D000368:Aged; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D009473:Neuronal Plasticity; D017594:Publication Bias; D011712:Pyramidal Tracts / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C579455:BDNF protein, human
keywords: Cortical excitability; Motor cortex; Motor-evoked potentials (MEPs); Neuromodulation; Theta-burst stimulation (TBS); Transcranial magnetic stimulation (TMS)