Quantitative Electroencephalogram (qEEG) as a Natural and Non-Invasive Window into Living Brain and Mind in the Functional Continuum of Healthy and Pathological Conditions

Abstract

Many practicing clinicians are time-poor and are unaware of the accumulated neuroscience developments. Additionally, given the conservative nature of their field, key insights and findings trickle through into the mainstream clinical zeitgeist rather slowly. Over many decades, clinical, systemic, and cognitive neuroscience have produced a large and diverse body of evidence for the potential utility of brain activity (measured by electroencephalogram—EEG) for neurology and psychiatry. Unfortunately, these data are enormous and essential information often gets buried, leaving many researchers stuck with outdated paradigms. Additionally, the lack of a conceptual and unifying theoretical framework, which can bind diverse facts and relate them in a meaningful way, makes the whole situation even more complex. To contribute to the systematization of essential data (from the authors’ point of view), we present an overview of important findings in the fields of electrophysiology and clinical, systemic, and cognitive neuroscience and provide a general theoretical–conceptual framework that is important for any application of EEG signal analysis in neuropsychopathology. In this context, we intentionally omit detailed descriptions of EEG characteristics associated with neuropsychopathology as irrelevant to this theoretical–conceptual review.

Neuropsychological Evaluation and Quantitative EEG in Patients with Frontotemporal Dementia, Alzheimer’s Disease, and Mild Cognitive Impairment

“…We believe that by using tests with different methodological approaches (neuropsychological analysis and qEEG) we can better characterize the dysfunction of the brain system. On one hand, the use of qEEG is economical, fast, reproducible, and yields precise data in neurology and psychiatry that can be compared over time [ 56 ]. In line with previous observations [ 14 , 15 , 16 ], we observed that the QEEG data (delta and theta bands and their spatial distribution) allow a distinction between FTD, AD, and healthy aging controls.…”

Patients with Disorders of Consciousness: Are They Nonconscious, Unconscious, or Subconscious? Expanding the Discussion

“…Now that we have this overview in place, we can move on to the topic of our analysis. Next, we will advance the analysis of these three phenomena (described by three concepts above; Figure 1) by exploring in more detail their neurophenomenology and mutual relationship within the common conceptual framework (Operational Architectonics [24,25]) stemming from the advanced analysis of the EEG neuroimaging technique [89][90][91]. Operational, in this context, refers to the notion of 'operation', which is both a process lasting in time and simultaneously an event that has a beginning and an end [24,25].…”

Biomedical Signal Processing: Understanding Its Importance and Several Fundamental Steps

“…Several fundamental steps and techniques are used in this process to identify the physiological dysfunctions of human bodies. Electroencephalogram or EEG is one of the most influential tools used in the diagnosis of cardiac disorders or muscle movement misbalancing along with abnormal neural activities [8]. ECG is another initial cardiac dysfunction identification method under biomedical signal processing that helps to classify the signals along with analysing the signal to take preventive measures.…”