The use of low-density EEG for the classification of PPA and MCI

Panteleimon Chriskos ¹ Kyriaki Neophytou ^2* Christos A. Frantzidis ³ Jessica Gallegos ² Alexandros Afthinos ⁴ Chiadi Onyike ² Argye Hillis ² Panagiotis D Bamidis ¹ Kyrana Tsapkini ^2,5

• ¹ Laboratory of Medical Physics and Digital Innovation, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
• ² Johns Hopkins Medicine, Johns Hopkins University, Baltimore, Maryland, United States
• ³ School of Computer Science, College of Science, University of Lincoln, Lincoln, England, United Kingdom
• ⁴ Cooper Medical School of Rowan University, Camden, New Jersey, United States
• ⁵ Department of Cognitive Science, Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, Maryland, United States

Objective: Dissociating Primary Progressive Aphasia (PPA) from Mild Cognitive Impairment (MCI) is an important, yet challenging task. Given the need for low-cost and time-efficient classification, we used low-density electroencephalography (EEG) recordings to automatically classify PPA, MCI and healthy control (HC) individuals. To the best of our knowledge, this is the first attempt to classify individuals from these three populations at the same time. Method: We collected three-minute EEG recordings with an 8-channel system from eight MCI, fourteen PPA and eight HC individuals. Utilizing the Relative Wavelet Entropy method, we derived (i) functional connectivity and (ii) graph theory metrics and extracted (iii) various energy rhythms. Features from all three sources were used for classification. The k-Nearest Neighbor and Support Vector Machines classifiers were used. Results: A 100% individual classification accuracy was achieved in the HC-MCI, HC-PPA, and MCI-PPA comparisons, and a 77.78% accuracy in the HC-MCI-PPA comparison. Conclusions: We showed for the first time that successful automatic classification between HC, MCI and PPA is possible with short, low-density EEG recordings. Despite methodological limitations of the current study, these results have important implications for clinical practice since they show that fast, low-cost and accurate disease diagnosis of these disorders is possible. Future studies need to establish the generalizability of the current findings with larger sample sizes and the efficient use of this methodology in a clinical setting.