40-Hz rTMS over the bilateral angular gyrus significantly improved cognitive function for up to 8 weeks compared with sham stimulation in patients with probable Alzheimer's disease.
RCT (n=37)
Does 40-Hz high-frequency repetitive transcranial magnetic stimulation (rTMS) improve cognitive function in patients with probable Alzheimer's disease?
Modulating gamma-band oscillations with 40-Hz rTMS improves cognitive function and brain connectivity in patients with probable Alzheimer's disease.
Dementia causes a substantial global economic burden, but effective treatment is lacking. Recently, studies have revealed that gamma-band waves of electrical brain activity, particularly 40 Hz oscillations, are closely associated with high-order cognitive functions and can activate microglia to clear amyloid-β deposition. Here, we found that compared with sham stimulation, applying 40-Hz high-frequency repetitive transcranial magnetic stimulation (rTMS) over the bilateral angular gyrus in patients with probable Alzheimer's disease (AD; n = 37) resulted in up to 8 weeks of significantly improved cognitive function. Power spectral density analysis of the resting-state electroencephalography (EEG) demonstrated that 40-Hz rTMS modulated gamma-band oscillations in the left posterior temporoparietal region. Further testing with magnetic resonance imaging and TMS-EEG revealed the following: 40-Hz rTMS 1) prevented gray matter volume loss, 2) enhanced local functional integration within bilateral angular gyrus, as well as global functional integration in bilateral angular gyrus and the left middle frontal gyrus, 3) strengthened information flow from the left posterior temporoparietal region to the frontal areas and strengthened the dynamic connectivity between anterior and posterior brain regions. These findings demonstrate that modulating gamma-band oscillations effectively improves cognitive function in patients with probable AD by promoting local, long-range, and dynamic connectivity within the brain.
Liu et al. (Tue,) conducted a rct in Probable Alzheimer's disease (AD) (n=37). 40-Hz high-frequency repetitive transcranial magnetic stimulation (rTMS) vs. Sham stimulation was evaluated on Cognitive function. 40-Hz rTMS over the bilateral angular gyrus significantly improved cognitive function for up to 8 weeks compared with sham stimulation in patients with probable Alzheimer's disease.