The Therapeutic Effects of Noninvasive Brain Stimulation Combined with Cognitive Training in Elders with Alzheimer’s Disease or Amnesic Mild Cognitive Impairment

Recent studies have indicated that noninvasive brain stimulation combined with cognitive interval (NIBS-CI) improved cognitive function in people with Alzheimer’s disease (AD) or Amnesic mild cognitive impairment (a-MCI). While previous interventions have demonstrated that a single targeted cognitive intervention can improve cognitive function, the outcomes of using both interventions simultaneously are less well-established. Therefore, this study aims to perform a meta-analysis to determine the effectiveness of NIBS-CI in treating cognitive impairment associated with AD and a-MCI, with the goal of obtaining novel insights into this combined intervention.

PubMed, Web of Science, ProQuest and Central Cochrane library databases were searched up to December 2022. The primary cognitive outcomes were extracted from the included article. A mean difference (MD) and standardized mean difference (SMD) with a 95% confidence interval were calculated by using random-effect models.

Twelve studies with a total of 587 AD patients were included. The findings demonstrated that NIBS-CI significantly improved cognitive function of AD patients in cognitive outcomes (SMD = −0.52, 95%CI (−0. 93, −0.11)) and ADAS-COG (MD = −1.16, 95%CI (−1.69, −0.63)). The pooled results showed that NIBS-CI did not improve cognitive function of AD patients in short-time memory (SMD = 0.057, 95%CI (−0.13, 0.25), P = 0.56) and long-time memory (SMD = 0.001, 95%CI (−0.20, 0.20), P = 0.99).

There is evidence for a positive effect of NIBS-CI on overall cognitive function of AD and a-MCI. Considering the limited sample size, it is important to interpret the findings related to memory with caution. To obtain more robust results, future studies should be conducted with larger sample sizes and incorporate objective neurophysiological and neuroimaging tools. These methodological enhancements will allow for a better understanding of the therapeutic targets and provide a more comprehensive assessment of the effects of NIBS-CI treatment.