Precision Neuromodulation for Diabetes-Associated Cognitive Decline: a Transcranial Electrical Stimulation Approach

BACKGROUND: Type 3 Diabetes (T3DM), marked by brain insulin resistance, is increasingly linked to neurocognitive decline and Alzheimer's pathogenesis, necessitating novel non-pharmacological interventions. This study investigated anodal transcranial direct current stimulation (tDCS) targeting the left DLPFC (F3 region) to improve cognitive deficits in insulin-dependent diabetic patients with diabetes-associated cognitive decline (DACD). METHODS: This study utilized a randomized, double-blind, two-group clinical trial design. Diabetic patients aged 60-80 years in Tehran and Bonab experiencing brain fog and cognitive decline constituted the target population. Recruitment and execution occurred from autumn 2024 to spring 2025. A purposive sampling method selected 23 matched participants per group, adhering to strict inclusion/exclusion criteria. Participants were then randomly assigned to either the experimental or control group. The experimental group received 30 tDCS sessions. Cognitive status and memory were assessed using the mini-mental state examination as the primary outcome and the prospective and retrospective memory questionnaire as a supplementary measure. Repeated Measures ANOVA analyzed the data. RESULTS: The results indicated that tDCS administered to the DLPFC in the experimental cohort significantly enhanced overall cognitive function and reduced subjective memory complaints (p < .01). Additionally, a statistically significant reduction in glycated hemoglobin was observed across nearly all participants in the experimental group (p < .01). CONCLUSION: These findings indicate that tDCS presents a promising, non-invasive therapeutic approach. It demonstrates potential for enhancing cognitive function in patients with DACD and for facilitating improved long-term glycemic control. This highlights the role of brain neuromodulation as a component in the management of diabetes-related complications.