Noninvasive brain stimulation for behavioural and psychological symptoms of dementia: A systematic review and meta‐analysis

Abstract

Background Pharmacological and conventional nonpharmacological treatments for behavioural and psychological symptoms of dementia (BPSD) have only modest efficacy. Furthermore, pharmacotherapy carries the risk of important side effects. Noninvasive brain stimulation (repetitive transcranial magnetic stimulation (TMS) or transcranial direct current stimulation (tDCS)) are valuable and safe for cognitive function in Alzheimer disease (AD). However, there have been few studies, and there is no consensus, regarding the use of these techniques to treat BPSD. Methods We performed a systematic review of the literature and meta‐analysis of studies reporting the effect of rTMS or tDCS on BPSD. Results Seven articles were included: five randomized, controlled clinical trials and two open‐label clinical trials. Five studies investigated the effects of rTMS and two the effects of tDCS. Both studies using tDCS reported no evidence of efficacy on BPSD, while two of the three RCTs using rTMS found statistically significant benefits. In an exploratory meta‐analysis with four of the RCT studies, we did not find evidence of efficacy of noninvasive brain stimulation techniques, with an overall effect of −0.02 (95% CI = −0.90, 0.94; I2 = 85%). However, when we used only the data from the studies that applied rTMS, we found a positive effect on BPSD, with an overall effect of −0.58 (95% CI = −1.02, −0.14; I2 = 0%). With regards to the adverse effects reported, these were mild and not clinically relevant. Conclusions Our results establish a tendency for efficacy of rTMS protocols on BPSD, while corroborating their safety and tolerability, suggesting the need for further research.

Strengthened theta-burst transcranial magnetic stimulation as an adjunctive treatment for Alzheimer’s disease: An open-label pilot study

“…Robust synaptic plasticity is critical for cognitive processes, such as learning and memory [7]. Liao and Sara et al demonstrated the efficacy of rTMS on cognitive function and behavioral psychiatric symptoms of AD [2,8]. In addition, the correlation analysis in our study demonstrated improvement in cognition assessment in addition to the improvement in depression symptoms (p > 0.05; see supplemental material).…”

“…Presently, successful neuroprotective or curative treatments for AD are lacking [1]. However, one promising alternative therapy is repetitive Transcranial Magnetic Stimulation (rTMS) [2]. Most studies have chosen the dorsolateral prefrontal cortex (DLPFC) as the stimulus target because of its neuroplasticity and important role in cognitive functions (such as association memory) [3].…”

Novel cognitive ageing rehabilitation with transcranial direct current stimulation

“…(11) Limit the vicious circle of autodestructive events due to the increased Ca2+ influx resulting from excessive membrane depolarization or intra-axonal Na+ overload in the context of ischemia or energetic resource failure. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]…”

Neuromodulation of Gamma-Range Auditory Steady-State Responses: A Scoping Review of Brain Stimulation Studies

“…Although the application of these methods has reportedly contributed to the positive outcomes in clinical states (e.g., see Lefaucheur et al, 2020 ), the effects induced in the brain are not fully understood. According to the growing number of meta-analyses, the efficacy of brain stimulation methods is inconsistent across different conditions, e.g., depression (Razza et al, 2020 ; Sonmez et al, 2019 ; Moffa et al, 2020 ), mild cognitive impairments and dementia (Vacas et al, 2019 ; Chou et al, 2020 ; Wang et al, 2020 ), anxiety and post-traumatic stress (Cirillo et al, 2019 ), autism spectrum disorders (Barahona-Corrêa et al, 2018 ), ADHD (Salehinejad et al, 2019 ), positive and negative symptoms of schizophrenia (Aleman et al, 2018 ; Kim et al, 2019 ; Yang et al, 2019 ). Further research could benefit from the combination of NIBS with different neurophysiological measures like ASSR.…”