Transcranial Direct Current Stimulation (tDCS): Mechanism, Evidence, and Clinical Considerations
Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique that delivers weak, constant direct current (typically 0.5–2 mA) to the cerebral cortex through saline-soaked sponge electrodes placed on the scalp. Unlike transcranial magnetic stimulation (TMS), tDCS does not directly trigger action potentials; instead, it modulates neuronal membrane potentials in a subthreshold manner—depolarizing neurons under…
