Recent advancements in optimising transcranial electrical stimulation: reducing response variability through individualised stimulation

Abstract

Transcranial electrical stimulation (tES) has garnered significant attention as a non-invasive neuromodulation technique with promising therapeutic potential for various neurological and neuropsychiatric conditions. However, considerable variability in response to tES both between and within-individuals is a prevailing issue. This review explored recent advancements in optimising tES through individualised protocols that consider individual head anatomy, neural oscillatory activities and dynamic changes in the neurophysiology of the stimulated brain. Real-time monitoring and closed-loop systems allow adaptive adjustments of stimulation parameters in response to ongoing brain activity, which holds promise for enhancing tES effectiveness and overcoming the challenge of inter-session response variability. Overall, the reviewed literature highlights the emerging trend towards individualised tES protocols as a means to unlock the full potential of tES in research and clinical use. While promising, further research is warranted to establish standardised methodologies and validate the efficacy of individually tailored tES protocols to realise its full potential.