Brain oscillations in Alzheimer's Disease: a resting state EEG analysis

• Grant number: 23/00839-2
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: August 01, 2023
• End date: July 31, 2024
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Thiago Luiz de Russo
• Grantee: Rafaella Mendes Zambetta
• Supervisor: Emiliano Santarnecchi
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Institution abroad: Harvard University, Boston, United States
• Associated to the scholarship: 19/14877-8 - Effect of the head-down tilt on intracranial pressure and cardiovascular control in healthy individuals: perspectives for spaceflights, BP.DD

Abstract

Dementia is a very impactful disease that is present all over the world. It causes functional dependence and lower quality of life in affected individuals. The main hypothesis of its cause is the accumulation of cortical amyloid beta plaque and intracellular neurofibrillary tangles in the neurons, leading to loss of synapses, neurons death and brain atrophy. This scenario affects brain electrical cortical activity. Studies suggest that there is a decrease in high frequency bands and an elevation of low frequency bands. Gamma power is the higher frequency band, and it may be the most difficult frequency to achieve in a patient with Alzheimer's Disease (AD). Gamma modulation with Transcranial Alternating Current Stimulation (tACS) might be able to improve brain oscillations and, consequently, cognitive functions and clinical outcomes. Objectives: to gain insight in resting EEG in AD at baseline and correlate with clinical outcome; and investigate EEG changes after tACS treatment. Methods: participants underwent cognitive and memory testing and resting-state EEG (rsEEG) before and after the treatment. Then, they received daily treatment with 40Hz (gamma) tACS-EEG delivered over the bilateral temporal lobes. In addition, before and after each stimulation session rsEEG were collected to detect changes in EEG oscillatory activity after stimulation. Data will be processed through the MATLAB software and the spectral analysis will be performed using the ENOBIO software, to define the brain frequency bands. Statistical Analysis: a normality and homogeneity test will be applied. To evaluate the effect of tACS, comparing the pre- and post-intervention moments, the paired t test will be performed in parametric case and Wincoxon test in non-parametric case. Spearman's rank correlation coefficient will be used to determine the relationship between EEG and clinical outcomes. For all analyses, a significance level of 5% and a range of 95% confidence will be considered. (AU)