This poster was presented at the 30th annual Psych Congress, held Sept. 16-19, 2017, in New Orleans, Louisiana.
tDCS (transcranial Direct Current Stimulation) is a potentially powerful treatment modality for depression, dementia, pain, auditory hallucinations, fibromyalgia, headache and other conditions. Optimal treatment parameters have not been established. Precise effects on brain physiology are not known. We set out to expand the dose range and document the effect of high current using Electroencephalogram.
Methods: EEGs were recorded before and after stimulation, three minutes eyes closed, recorded and analyzed for MicroStates and Spectral Power using NeuroGuide and EEGLab/MatLab. Two stimulation devices each with maximum current of 4 mA were used to achieve 8 mA total current. Large (3") carbon-silicon electrodes fitted with saline soaked sponges were used for safety. Current density was calculated by (current«time/surface area). Anodes were placed between FP1and F3 (Brodmann's Area 10- The frontal pole) cathodes were placed at O1 and O2. Two stimulations were administered on separate days, the first five minutes and the second 20 minutes. There were no adverse effects.
Results: Microstate analysis did not reveal any significant changes. Power analysis however demonstrated increase in the Delta and Theta frequency bands (24% 5 min, 180% 20 min) and decrease in beta and gamma.
Discussion: To our knowledge this is the first report of 8 mA tDCS in human. The increased magnitude of the effect with the longer stimulation may suggest a dose response relationship. Further study is required to establish this in a more rigorous fashion. Higher current tDCS may hold the potential of therapeutic effect as well.