We perform a cognitive screening test based on quantitative electroencephalography (EEG), which is used to detect brain-wave slowing (i.e., the shift of spectral power from higher to lower EEG frequencies [1,2,3]). Brain-wave slowing may be associated with cortical neurodegenerative changes [4,5,6] and can thus be used as a screening tool for early dementia detection [7,8,9].
We measure brain-wave slowing with the BrainTrip Dementia Index (BDI)* test . During the BDI test, 4 minutes of resting state EEG with eyes open and 4 minutes with eyes closed is recorded. The EEG data is then algorithmically pre-processed and used to measure brain-wave slowing. The result of the BDI test is an estimate of brain-wave slowing, which is presented on a scale between 0 and 100 points.
BDI values between 60 and 100 points indicate that EEG frequencies are within the normal or reference range. BDI values between 40-60 points are intermediate and indicate only a mild slowing of EEG waves. BDI values between 0-40 points indicate a noticeable slowing of EEG waves, which suggests the probable presence of cortical changes potentially related to cognitive decline or dementia. At the cut-off score of 50 points, the BDI test has 94% specificity and 77% sensitivity for detecting cognitive decline or dementia.
 Nunez, P. L., & Srinivasan, R. (2005). Measures of EEG Dynamic Properties. In Electric Fields of the Brain: The Neurophysics of EEG, 2nd Edition (2nd ed., pp. 353–428). Oxford University Press.
 Drongelen, V. W. (2018). 1-D and 2-D Fourier Transform Applications. In Signal Processing for Neuroscientists: An Introduction to the Analysis of Physiological Signals (2nd ed., pp. 119–152). Academic Press.
 Vecchio, F., Babiloni, C., Lizio, R., Fallani, F. D. V., Blinowska, K., Verrienti, G., ... & Rossini, P. M. (2013). Resting state cortical EEG rhythms in Alzheimer's disease: toward EEG markers for clinical applications: a review. Supplements to Clinical neurophysiology, 62, 223-236.
 Schomer, D. L., & da Silva, F. L. H. (2018). EEG in dementing disorders. In Niedermeyer’s Electroencephalography: Basic Principles, Clinical Applications, and Related Fields (7th ed., pp. 413–432). Oxford University Press.
 Jeong, J. (2004). EEG dynamics in patients with Alzheimer's disease. Clinical neurophysiology, 115(7), 1490-1505.
 Meghdadi, A. H., Stevanović Karić, M., McConnell, M., Rupp, G., Richard, C., Hamilton, J., ... & Berka, C. (2021). Resting state EEG biomarkers of cognitive decline associated with Alzheimer’s disease and mild cognitive impairment. PloS one, 16(2), e0244180.
 Engedal, K., Snaedal, J., Hoegh, P., Jelic, V., Andersen, B. B., Naik, M., ... & Oeksengaard, A. R. (2015). Quantitative EEG applying the statistical recognition pattern method: a useful tool in dementia diagnostic workup. Dementia and geriatric cognitive disorders, 40(1-2), 1-12.
 Musaeus, C. S., Engedal, K., Høgh, P., Jelic, V., Mørup, M., Naik, M., ... & Andersen, B. B. (2018). EEG theta power is an early marker of cognitive decline in dementia due to Alzheimer’s disease. Journal of Alzheimer's Disease, 64(4), 1359-1371.
 Ferreira, D., Jelic, V., Cavallin, L., Oeksengaard, A. R., Snaedal, J., Høgh, P., ... & Wahlund, L. O. (2016). Electroencephalography is a good complement to currently established dementia biomarkers. Dementia and Geriatric Cognitive Disorders, 42(1-2), 80-92.
 Dreo, J., Jug, J., Pavlovčič, T., Ogrin, A., Aljaž, B., Sakić, D. (2022, November 13). Validation of an EEG based dementia screening test [Conference lecture], Abstract Control Number: 5241, Society for Neuroscience meeting, San Diego, CA, United States
 Nasreddine, Z. S., Phillips, N. A., Bédirian, V., Charbonneau, S., Whitehead, V., Collin, I., ... & Chertkow, H. (2005). The Montreal Cognitive Assessment, MoCA: a brief screening tool for mild cognitive impairment. Journal of the American Geriatrics Society, 53(4), 695-699.
 Russo MJ, Iturry M, Sraka MA, Bartoloni L, Carnero Pardo C, Allegri RF. Diagnostic accuracy of the Phototest for cognitive impairment and dementia in Argentina. Clin Neuropsychol. 2014;28(5):826-40. doi: 10.1080/13854046.2014.928748. Epub 2014 Jun 27. PMID: 24970674.
 Carnero-Pardo, C., Gurpegui, M., Sanchez-Cantalejo, E., Frank, A., Mola, S., Barquero, M. S., Montoro-Rios, M. T., & Trans-EUROTEST Group (2006). Diagnostic accuracy of the Eurotest for dementia: a naturalistic, multicenter phase II study. BMC neurology, 6, 15. https://doi.org/10.1186/1471-2377-6-15
* BDI testing is a cognitive screening tool and cannot, by itself, confirm or exclude the presence of dementia. BDI test results must always be interpreted in the context of the subject’s overall health status in consultation with a medical doctor, clinical psychologist, or another specialist trained to evaluate human cognitive processes.