Brain Stimul
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Randomized Controlled Trial
Evidence for a role of the right dorsolateral prefrontal cortex in controlling stimulus-response integration: a transcranial direct current stimulation (tDCS) study.
Acting coherently upon stimuli requires some kind of integration of stimulus and response features across various distinct cortical feature maps (one aspect of the binding problem). Although the process of feature binding proper seems rather automatic, recent studies revealed that the management of stimulus-response bindings is less efficient in populations with impaired cognitive-control processes. ⋯ This finding provides empirical support for a role of the right DLPFC in feature-binding management, which might consist in preventing the stimulus-induced activation of previously created, but now task-irrelevant, episodic bindings. From a methodological perspective, the finding may suggest that tDCS could be used as a temporary, reversible "brain lesion" generator in healthy subjects, enabling experimental investigation of how the brain works.
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Deep brain stimulation, specifically high-frequency stimulation (HFS), is an alternative and promising treatment for intractable epilepsies; however, the optimal targets are still unknown. The thalamic reticular nucleus (TRN) occupies a key position in the modulation of the cortico-thalamic and thalamo-cortical pathways. ⋯ These data indicate that HFS-TRN has an anti-epileptogenic effect and is able to modify seizure synchrony and interrupt abnormal EEG recruitment of thalamo-cortical and, indirectly, cortico-thalamic pathways.
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The importance of slow-wave sleep (SWS), hallmarked by the occurrence of sleep slow oscillations (SO), for the consolidation of hippocampus-dependent memories has been shown in numerous studies. Previously, the application of transcranial direct current stimulation, oscillating at the frequency of endogenous slow oscillations, during SWS enhanced memory consolidation for a hippocampus dependent task in humans suggesting a causal role of slowly oscillating electric fields for sleep dependent memory consolidation. ⋯ These results support the hypothesis that slowly oscillating electric fields causal affect sleep dependent memory consolidation, and demonstrate that oscillatory tDCS can be a valuable tool to investigate the function of endogenous cortical network activity.
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Randomized Controlled Trial Multicenter Study
A two-site pilot randomized 3 day trial of high dose left prefrontal repetitive transcranial magnetic stimulation (rTMS) for suicidal inpatients.
Suicide attempts and completed suicides are common, yet there are no proven acute medication or device treatments for treating a suicidal crisis. Repeated daily left prefrontal repetitive transcranial magnetic stimulation (rTMS) for 4-6 weeks is a new FDA-approved treatment for acute depression. Some open-label rTMS studies have found rapid reductions in suicidality. ⋯ Delivering high doses of left prefrontal rTMS over three days (54,000 stimuli) to suicidal inpatients is possible and safe, with few side effects and no worsening of suicidal thinking. The suggestions of a rapid anti-suicide effect (day 1 SSI data, Visual Analogue Scale data over the 3 days) need to be tested for replication in a larger sample.
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Transcranial direct current stimulation (tDCS) is known to reliably alter motor cortical excitability in a polarity dependent fashion such that anodal stimulation increases cortical excitability and cathodal stimulation inhibits cortical excitability. However, the effect of tDCS on agonist and antagonist volitional muscle activation is currently not known. ⋯ Our results indicate that anodal tDCS significantly affects the voluntary EMG/force relationship of the agonist muscles without altering the coactivation of the antagonistic muscles. The most likely explanation for the observed greater EMG per unit force after anodal tDCS appears to be related to alterations in motor unit recruitment strategies.