Modulated theta band frequency with binaural beat stimulation correlates with improved cognitive scores in Alzheimer's patients

Abstract

Introduction: Alzheimer's disease (AD) affects 50 million individuals worldwide, a number projected to triple by 2050. Due to discomfort through electrical and magnetic neuromodulation technologies, this is the first study to propose the potential of auditory binaural beat (BB) stimulation at an alpha frequency (10 Hz) for enhancing cognitive and neurological outcomes in AD patients.

Methods: Twenty-five patients were divided into the experimental-Group (n = 15) and control-Group (n = 10). Psychometric and neurological assessments were conducted Pre-Treatment (Day 1) and Post-Treatment (Day 14) following consecutive days of binaural beats (BB) or auditory tone stimulation administered from Day 2 to Day 13.

Results: A two-way ANOVA revealed a significant main effect of group (F = 6.087, p = 0.016) and session (F = 3.859, p = 0.024) on MMSE scores, with the experimental group showing significant improvement in MMSE scores (t = 7.33, p = 0.00000012) compared to the control group (p = 0.2306). Paired t-tests revealed a significant reduction in depression scores (DASS-21, t = 1.701, p = 0.0253) in the experimental group, while no significant improvements were noted in the control group. EEG recordings revealed significant changes in α-band, β-band, and γ-band power (p < 0.05). Moreover, The correlation between EEG bands and MMSE subparts showed that increased θ-band power in the experimental group was positively correlated (p < 0.05) with the frontal region during language tasks and in the frontal and central regions during registration and orientation tasks, indicating potential neurocognitive benefits.

Discussion: The results of this research imply that BB stimulation has untapped potential as a non-invasive therapy for patients with AD, hence there is the need for further studies to manage the dementia epidemic.

Keywords: Alzheimer’s disease; EEG; binaural beat; cognitive score; correlation.

FIGURE 1

Participant selection criteria for the study.

FIGURE 2

Experiment protocol for experimental- and control groups of AD patients. Pre-Treatment represents psychometric assessments and neurological recording on day 1, During treatment represents BB stimulation days from day 2 to 13 and Post-Treatment represents psychometric assessments and neurological recording on day 14. A follow-up session was taken after two weeks of Post-Treatment, focusing solely on psychometric assessments (MMSE scores).

FIGURE 3

Comparison of MMSE total within group scores between Pre- and Post-Treatment phases. Bars represent the mean and SD of Pre-Treatment score (blue bars), Post-Treatment score (orange bar), and Follow-up score (gray bar). * Indicate the significant difference (p < 0.025) in MMSE score between the Post-Treatment (Day 14) and follow-up sessions as compared to Pre-Treatment (Day 1) in both groups.

FIGURE 4

Mini-Mental State Exam (MMSE) mean scores of each section (Orientation, Registration, Recall, Attention, Language, and Copying) for Pre- and Post-Treatment (Day 14) of Experimental- and Control-Group. Bars represent the mean and SD of Pre-Treatment (blue bars), Post-Treatment of the Experimental-Group (orange bars), and Post-Treatment of Control-Group (gray bars). * Indicate the significant difference (p < 0.025) in MMSE score between the Post-Treatment (Day 14) as compared to Pre-Treatment (Day 1) in both groups.

FIGURE 5

Comparison of patients’ scores for the DASS-21 questionnaire for all three conditions (Depression, Anxiety, and Stress). The Blue Bar represents Pre-Treatment, the orange bar represents Post-Treatment (Experimental group) and the Gray bar represents Post-Treatment (Control group). * Indicates the significant difference (p < 0.05) in DAAS score between Post-Treatment (Day 14) as compared to Pre-Treatment (Day 1) in both groups.

FIGURE 6

EEG power spectrums for Experimental-Group and statistical comparisons between states in four frequency bands (θ, α, β, and γ). Rows represent frequency bands (first row: θ-band, second row: α-band, third row: β-band, fourth row: 7-band). Columns represent the power spectrum in four states (Pre-Treatment EC; first column, Post-Treatment EC; second column, Pre-Treatment EO; third column and fourth column; Post-Treatment EO), statistical comparisons between Pre-Treatment EC vs. Post-Treatment EC and Pre-Treatment EO vs. Post-Treatment EO states (significant changes in column 5 and 6, respectively) and effect size between Pre-Treatment EC vs. Post-Treatment EC and Pre-Treatment EO vs. Post-Treatment EO states (column 7 and 8, respectively). Gray dots represent a significant increase and black dots represent a significant decrease.

FIGURE 7

EEG power spectrums for Control group and statistical comparisons between states in four frequency bands (θ, α, β, and γ). Rows represent frequency bands (first row: θ-band, second row: α-band, third row: β-band, fourth row: 7-band). Columns represent the power spectrum in four states (Pre-Treatment EC; first column, Post-Treatment EC; second column, Pre-Treatment EO; third column and fourth column; Post-Treatment EO), statistical comparisons between Pre-Treatment EC vs. Post-Treatment EC and Pre-Treatment EO vs. Post-Treatment EO states (significant changes in column 5 and 6, respectively) and effect size between Pre-Treatment EC vs. Post-Treatment EC and Pre-Treatment EO vs. Post-Treatment EO states (column 7 and 8, respectively). Gray dots represent a significant increase and black dots represent a significant decrease.

FIGURE 8

Correlation between MMSE scores (Orientation, Registration, and Language) and PSD of each EEG channel for Pre-Treatment and Post-Treatment (Experimental group). Columns represent the sessions (Pre-Treatment and Post-Treatment experimental group) of MMSE score (Orientation, Registration, and Language) of frequency bands (θ and α). The first row in each frequency band represents the correlation values, while the second row shows the significance values. Gray dots indicate a significant positive correlation, and black dots indicate a significant negative correlation. The scale from –1 to 0 represents a negative correlation, while the scale from 0 to 1 represents a positive correlation.