Sham tDCS: A hidden source of variability? Reflections for further blinded, controlled trialsTranscranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique increasingly used to modulate neural activity in the living brain. In order to establish the neurophysiological, cognitive or clinical effects of tDCS, most studies compare the effects of active tDCS to those observed with a sham tDCS intervention. In most cases, sham tDCS consists in delivering an active stimulation for a few seconds to mimic the sensations observed with active tDCS and keep participants blind to the intervention.
Durability of antidepressant response to repetitive transcranial magnetic stimulation: Systematic review and meta-analysisThe therapeutic options for treatment-resistant depression (TRD) encompass a range of neuromodulatory techniques, including repetitive transcranial magnetic stimulation (rTMS). While rTMS is safe and has documented short-term efficacy, durability of antidepressant effects is poorly established.
Modulation of motor cortex excitability predicts antidepressant response to prefrontal cortex repetitive transcranial magnetic stimulationRepetitive transcranial magnetic stimulation (rTMS) targeting the left dorsolateral prefrontal cortex (DLPFC) is a treatment option for patients with medication-resistant major depressive disorder (MDD). However, antidepressant response is variable and there are currently no response predictors with sufficient accuracy for clinical use.
The Clinical TMS Society Consensus Review and Treatment Recommendations for TMS Therapy for Major Depressive DisorderTMS therapy uses a computerized, electromechanical medical device to produce and deliver non-invasive, magnetic stimulation using brief duration, rapidly alternating, or pulsed, magnetic fields to induce electrical currents directed at spatially discrete regions of the cerebral cortex. This method of cortical stimulation by application of brief magnetic pulses to the head is known as transcranial magnetic stimulation or TMS. When pulses of TMS are delivered repetitively, this is called repetitive TMS, or rTMS.
Neurochemical Modulation in Posteromedial Default-mode Network Cortex Induced by Transcranial Magnetic StimulationThe Default Mode Network (DMN) is severely compromised in several psychiatric and neurodegenerative disorders where plasticity alterations are observed. Glutamate and GABA are the major excitatory and inhibitory brain neurotransmitters respectively and are strongly related to plasticity responses and large-scale network expression.
Targeting of White Matter Tracts with Transcranial Magnetic StimulationTMS activations of white matter depend not only on the distance from the coil, but also on the orientation of the axons relative to the TMS-induced electric field, and especially on axonal bends that create strong local field gradient maxima. Therefore, tractography contains potentially useful information for TMS targeting.