Repetitive transcranial magnetic stimulation enhances alpha power in Alzheimer's disease patients

TL;DR

This study shows that repetitive transcranial magnetic stimulation increases alpha brain waves in Alzheimer's patients, but does not improve memory.

Contribution

The study demonstrates that low-intensity rTMS can modulate alpha oscillations in Alzheimer's patients at rest.

Findings

rTMS increased alpha power by 25% in Alzheimer's patients compared to sham stimulation.

No significant improvement in memory performance was observed with rTMS.

Alpha frequency-tuned rTMS modulates pathological brain activity in AD patients at low intensities.

Abstract

With Alzheimer's disease (AD) presenting an ongoing challenge, innovative treatment methods are essential. Repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising noninvasive intervention, particularly targeting alpha band oscillations associated with AD-related cognitive decline.

This study aimed to investigate the effects of low-intensity rTMS over posterior cortical areas on alpha band oscillations and memory performance in AD patients compared to age-matched healthy controls.

In a single-blinded, sham-controlled rTMS-EEG study, we examined 14 amyloid-positive AD patients and 14 age-matched healthy controls. Continuous EEG was recorded at rest (eyes closed) before, during, and after stimulation. During stimulation, participants completed an episodic memory task.

We were able to demonstrate that during rTMS alpha power increased compared to sham, with a notable 25% increase observed in AD patients. However, comparison of memory performance under the sham and stimulation conditions revealed no significant stimulation effect.

These findings support and extend current knowledge of noninvasive brain stimulation mechanisms. Our results suggest that alpha frequency-tuned rTMS over posterior cortical areas can modulate pathological brain activity in AD patients even at low intensities. Given the limited sample size and moderate effect sizes, results should be interpreted with caution. Nevertheless, our results warrant further studies with long-term EEG-rTMS protocols to evaluate the potential therapeutic benefit.

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