Longitudinal analysis of qEEG in subjects with autosomal dominant Alzheimer’s disease due to PSEN1‐E280A variant

Background Alzheimer’s disease (AD) is the leading cause of dementia in the world. Synaptic dysfunction is a pathophysiological event that alters neuronal connections at multiple scales: molecular, cellular, brain networks, cerebral cortex, among others. There are different mechanisms that interact to trigger alterations in the homeostasis of synaptic function, among them the most prominent are amyloidosis, tauopathy and inflammation. EEG has been used in recent years as a cost‐effective, portable, and noninvasive alternative for the study of biomarkers in Alzheimer’s disease. Method All participants were members of families with PSEN1‐E280A genetic variant and healthy controls recruited voluntarily. A longitudinal follow‐up was planned, this study collects data from the initial visit and in the first year of follow‐up. At each visit, neurological and neuropsychological evaluation and electroencephalogram were performed. We analyzed the resting state EEG spectral power bands and the Alpha/Theta reactivity index. Result Alpha1 and Alpha2 frequency bands did not have significant changes in the follow‐up year, in the Beta3 frequency band in component 20 and Beta2 in component 22 statistically significant differences were found. However, the distribution of the data in the shift graphs for the Beta frequency band presents some slopes, which indicates a modest effect sizes and low precision. Conclusion The Beta frequency band is a potential neurophysiological marker that in preclinical stages of ADAD show statistically significant differences between asymptomatic carriers and non‐ carriers. This signal is related to components whose origin is estimated in posterior regions, which highlights the importance of previous findings in the precuneus. However, the effect sizes were modest and with low precision. It would recommend larger samples and longer following in future research.