Transcranial Direct Current Stimulation (tDCS) Dose Response: Lecture by Marom Bikson
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- Опубліковано 11 вер 2024
- Detailed slides can be downloaded here www.neuralengr...
And the core paper references can be downloaded here www.neuralengr...
Abstract from core paper:
Background: Transcranial direct current stimulation (tDCS) is investigated to modulate neuronal function by applying a fixed low-intensity direct current to scalp. Objectives: We critically discuss evidence for a monotonic response in effect size with increasing current intensity, with a specific focus on a question if increasing applied current enhance the efficacy of tDCS. Methods: We analyzed tDCS intensity does-response from different perspectives including biophysical modeling, animal modeling, human neurophysiology, neuroimaging and behavioral/clinical measures. Further, we discuss approaches to design dose-response trials. Results: Physical models predict electric field in the brain increases with applied tDCS intensity. Data from animal studies are lacking since a range of relevant low-intensities is rarely tested. Results from imaging studies are ambiguous while human neurophysiology, including using transcranial magnetic stimulation (TMS) as a probe, suggests a complex state-dependent non-monotonic dose response. The diffusivity of brain current flow produced by conventional tDCS montages complicates this analysis, with relatively few studies on focal High Definition (HD)-tDCS. In behavioral and clinical trials, only a limited range of intensities (1-2 mA), and typically just one intensity, are conventionally tested; moreover, outcomes are subject brain-state dependent. Measurements and models of current flow show that for the same applied current, substantial differences in brain current occur across individuals. Trials are thus subject to inter-individual differences that complicate consideration of population-level dose response. Conclusion: The presence or absence of simple dose response does not impact how efficacious a given tDCS dose is for a given indication. Understanding dose-response in human applications of tDCS is needed for protocol optimization including individualized dose to reduce outcome variability, which requires intelligent design of dose-response studies.
Many people want to know how long the tDCS can solve their problem, This lecture is useful.
Volts per Meter? Current per area is definitely an important factor in tdcs. But, V/m makes no sense.
It is a subtle but important idea. We control the applied voltage or the applied current. This is a single number if we talk about peak stimulation intensity,
INSIDE the tissue we produce a current density (A/m2) or equivalently an electric field (V/M). Because the current density and electric field vary across different parts of the body, there is no *single* current current or electric field across the entire body. There is therefore a *distribution* across the body. There is a single current density or electric field if we focus on just one tissue area.
See these slides if they help static1.squarespace.com/static/5cd3231cd7819e6ae55fedb4/t/63bf12769d51a072a5f419c9/1673466494836/2023_NANS_Bikson_Marom_Lecture1_EngineeringPrinciples_Final2a.pdf
terrible audio
👍
Have you tasted this on frontal lobe mTBI patients?
Tastes like chicken