Technical and statistical milestones and standards for construction, validation and/or comparison of Quantitative Electroencephalogram (QEEG) normative databases

Abstract

Quantitative electroencephalogram (QEEG) and the QEEG normative database help in characterization of normal versus neurocognitive diseases, in diagnosis and prognosis and in treatment tailoring. Constructing QEEG normative databases and standardization of QEEG protocols for use in both research and clinical settings has proven challenging over the last 61 years. The present paper focuses on a) historical and technical milestones the field had to overcome, b) standards to be followed when constructing and validating a normative databases, c) commonly used normative databases, and d) provides an illustrated step-by-step guide to QEEG normative database validation and comparison. *Correspondence to: Jonathan RT Lakey, PhD, MSM, Department of Surgery, 333 City Blvd West, Suite 1600, Orange, CA 92868, USA, Tel: 1-949-824-8022; Fax: 1-714-456-6188; E-mail: jlakey@hs.uci.edu Received: January 07, 2021; Accepted: January 31, 2021; Published: February 08, 2021 Other areas where QEEG has made unique contributions include; epilepsy screening and in drug-resistant epilepsy, in court sentencing, pharmaco-QEEG, neurocognitive issues, traumatic brain injury (TBI) severity, post-concussion syndrome, mood disorders, exoor endogenously induced behavioral disorders, attention deficit disorder (ADD/ADHD), schizophrenia, depression, tinnitus, encephalopathies and alcohol and/or substance abuse [3-7]. On the issue of differential diagnosis of cross-border diseases another parallel development which has bearing on QEEG’s usefulness as a diagnostic and prognostic tool is the Diagnostic and Statistical Manual of Mental Disorders (DSM) (Figure 1) [8]. Changes in disease definitions and classification as per the DSM influence cross-study comparability, QEEG derived biomarker reliability and validity. However, DSM-5, released in 2013 keeping in mind neurocognitive developments in the field has helped lay to rest many of the issues pertinent to disease classification [8]. The backbone of the QEEG is the normative database (a term coined by Graham and Dietlien in 1965) used in drawing comparisons [9]. In the hands of the untrained (operators, data analyzers and interpreters), the QEEG can yield results that are not of clinical relevance [10]. Therefore, over the last 61 years several QEEG standards have been developed to ensure. • The validity and reliability of QEEG for research and clinical use in diagnosis, prognosis and pharmaco-QEEG, • That a balance between “standardized medicine” and “precision medicine” is struck so as to meet the World Health Organization Miranda P (2021) Technical and statistical milestones and standards for construction, validation and/or comparison of Quantitative Electroencephalogram (QEEG) normative databases J Syst Integr Neurosci, 2021 doi: 10.15761/JSIN.1000247 Volume 7: 2-13 Figure 1. History of the scientific, technical and statistical improvements in constructing QEEG normative databases Miranda P (2021) Technical and statistical milestones and standards for construction, validation and/or comparison of Quantitative Electroencephalogram (QEEG) normative databases J Syst Integr Neurosci, 2021 doi: 10.15761/JSIN.1000247 Volume 7: 3-13 (WHO) “High 5s Project” goals to ensure patient safety and finally [11]. • To meet health insurance requirements [11-17]. • Standard methods of EEG data acquisition, visualization (synchronization, connectivity and topographic features), processing (de-artifaction, extraction and classification), storage and statistical comparisons have been and are in continuous development (Figure 1) [9-17]. • Standard methods of normative databases construction, guidelines on the same and FDA registered normative databases. • World-wide efforts are on to generate long-tailed data and merge them to generate big data that will allow for both cross-study and cross-cultural comparisons [16-18]. The goal of this paper is to present; i) a brief historical review of technical and statistical milestones and standards that apply to QEEG and QEEG normative databases over the last 61 years (Figures 1 and 2) (Table 1), ii) protocols involved in normative database evaluation and comparison (Figure 3), iii) common normative QEEG databases in use and iv) to provide a step-by-step guide to normative database evaluation and comparison from EEG recording to Z-score computing, followed by construction of topographic maps using EEG machines like BrainView by Medeia (Figures 4a, 4b).