Effects of rTMS treatment on global cognitive function in Alzheimer's disease: A systematic review and meta-analysis

Abstract

BackgroundAlthough repetitive transcranial magnetic stimulation (rTMS) has been extensively studied in patients with Alzheimer's disease (AD), the clinical evidence remains inconsistent. The purpose of this meta-analysis was to evaluate the effects of rTMS on global cognitive function in patients with AD.MethodsAn integrated literature search using 4 databases (PubMed, Web of Science, Embase, and Cochrane Library) was performed to identify English language articles published up to October 6, 2021. We pooled Mini-Mental State Examination (MMSE) and Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-Cog) scores using a random-effects model via RevMan 5.4 software. We calculated estimates of mean differences (MD) with 95% confidence intervals (CI). The primary outcomes were pre-post treatment changes in global cognition as measured using MMSE and ADAS-Cog immediately after rTMS treatment, and the secondary outcome was duration of cognitive improvement (1–1.5 and ≥3 months).ResultsNine studies with 361 patients were included in this meta-analysis. The results showed that rTMS significantly improved global cognitive function immediately following rTMS treatment [(MD) 1.82, 95% confidence interval (CI) 1.41–2.22, p < 0.00001, MMSE; 2.72, 95% CI, 1.77–3.67, p < 0.00001, ADAS-Cog], and the therapeutic effects persisted for an extended duration (2.20, 95% CI, 0.93–3.47, p =0.0007, MMSE; 1.96, 95% CI, 0.96–2.95, p = 0.0001, ADAS-Cog). Subgroup analyses showed that high frequency rTMS targeted to the left dorsolateral prefrontal cortex (DLPFC) for over 20 sessions induced the greatest cognitive improvement, with effects lasting for more than 1 month after the final treatment. There were no significant differences in dropout rate (p > 0.05) or adverse effect rate (p > 0.05) between the rTMS and control groups.ConclusionsRepetitive TMS is a potentially effective treatment for cognitive impairment in AD that is safe and can induce long-lasting effects. Our results also showed that ADAS-cog and MMSE differed in determination of global cognitive impairment.Systematic review registrationhttp://www.crd.york.ac.uk/PROSPERO, PROSPERO CRD42022315545.

Repetitive transcranial magnetic stimulation for Alzheimer’s disease: an overview of systematic reviews and meta-analysis

“…32 articles were considered potentially eligible and the full texts of the papers were downloaded. After independent review by two authors, 24 SRs/MAs were excluded and 8 SRs/MAs were included for final analysis ( Figure 1 ) ( Liao et al, 2015 ; Cheng and Wu, 2016 ; Liang et al, 2017 ; Dong et al, 2018 ; Lin et al, 2019 ; Wang et al, 2020 ; Zhang et al, 2022 ; Xiu et al, 2024 ).…”

“…Out of the 8 research reports, 4 were classified as critically low quality, while the remaining 4 were rated as low quality. Only two SRs/MAs received a rating of “Yes” for key item 2, while the others were rated as “No” due to the absence of a review scheme ( Dong et al, 2018 ; Zhang et al, 2022 ). Regarding key item 4, only one SR/MA did not present a comprehensive and detailed search strategy ( Cheng and Wu, 2016 ).…”

“…Among the 27 items, 16 items were fully reported (100%), and 11 items had missing or insufficient reporting. In the methods section, only 2 studies reported protocol and registration, with a reporting rate of 25% ( Dong et al, 2018 ; Zhang et al, 2022 ). Limitations were found in the risk of bias in individual studies (75%), synthesis of results (87.5%), risk of bias across studies (75%), and additional analyses (87.5%).…”

“…Domain 3 evaluates the collection and study appraisal, and all were rated as having a low risk of bias. Domain 4 assesses the attention given to the synthesis and findings, and six SRs/MAs (75%) were rated as having a low risk of bias ( Cheng and Wu, 2016 ; Dong et al, 2018 ; Lin et al, 2019 ; Wang et al, 2020 ; Zhang et al, 2022 ; Xiu et al, 2024 ). In stage 3, when considering the overall risk of bias, five SRs/MAs were rated as high risk because they did not provide any explanation or supplement regarding the risk of bias, while the remaining SRs/MAs were considered to have a low risk.…”

A Survey of Deep Learning for Alzheimer’s Disease

“…Common modalities include PET, MRI, and CT for diagnosis, and 3D-MRI [97], fMRI [98], and SPECT for research purposes. Various forms of cognitive assessments (CA) are also commonly available, including MMSE [29], CDR [99], ADAS-Cog [100,101], logical memory test [102,103], and postural kinematic analysis [104,105]. CSF, blood plasma biomarkers [106,107], and genetic data are available from several sources.…”