Tracking the current in the Alzheimer's brain - Systematic differences between patients and healthy controls in the electric field induced by tDCS

Several studies on patients with Alzheimer's disease (AD) have used transcranial direct current stimulation (tDCS) to enhance neural excitability in the left dorsolateral prefrontal cortex (lDLPFC). Interindividual differences brain anatomy AD pose a challenge efficiently target lDLPFC using scalp-based coordinates, calling for new and more precise tDCS protocols. The purpose of this study was explore how AD-related neuropathology affects tDCS-induced electric field (EF) across different DLPFC montages computational modeling. Forty-eight realistic head models were created from structural magnetic resonance scans healthy controls collected publicly available database. We compared EF applied literature, addition high definition (HD)-tDCS montage centered at electrode F3. There an overall global reduction strength patient group, probably due alterations that also identified group. A widespread distribution found frontal lobe bipolar montages, while HD-tDCS yielded focal stimulation, mainly restricted lDLPFC. Minor when comparing montages. Neurodegenerative present affect magnitude, variability EF. provide area, pronounced group between matched controls. This finding poses substantial limitations comparison cognitive effects both within stages progression.