Electroencephalogram Based Biomarkers for Detection of Alzheimer’s Disease

Abstract

Alzheimer's disease (AD) is an age-related progressive and neurodegenerative disorder, which is characterized by loss of memory and cognitive decline. It is the main cause of disability among older people. The rapid increase in the number of people living with AD and other forms of dementia due to the aging population represents a major challenge to health and social care systems worldwide. Degeneration of brain cells due to AD starts many years before the clinical manifestations become clear. Early diagnosis of AD will contribute to the development of effective treatments that could slow, stop, or prevent significant cognitive decline. Consequently, early diagnosis of AD may also be valuable in detecting patients with dementia who have not obtained a formal early diagnosis, and this may provide them with a chance to access suitable healthcare facilities. An early diagnosis biomarker capable of measuring brain cell degeneration due to AD would be valuable. Potentially, electroencephalogram (EEG) can play a valuable role in the early diagnosis of AD. EEG is noninvasive and low cost, and provides valuable information about brain dynamics in AD. Thus, EEG-based biomarkers may be used as a first-line decisionsupport tool in AD diagnosis and could complement other AD biomarkers.Keywords: EEG biomarkers, AD biomarkers, slowing of EEG, decrease in EEG coherence, reduction in EEG complexity, detection of Alzheimer's disease Neuroimaging -Neurobiology, Multimodal and Network Applications 2 an enormous financial. However, many dementia sufferers are not diagnosed early [7,8]. It is estimated that up to 50% of individuals with dementia may not have been diagnosed formally [8, 9]. In 2011, 28 million people out of 36 million people with dementia were not diagnosed worldwide [10].Degeneration of brain cells due to AD begins many years before clinical manifestations become noticeable [5,[11][12][13][14][15]. Early diagnosis of AD will help to the development of efficient treatments that could mitigate, stop, or prevent significant cognitive impairment [14, 16, 17]. Early diagnosis of AD may also be valuable in detecting patients with dementia who have not obtained a formal early diagnosis, and this may provide them with a chance to access suitable healthcare facilities [18][19][20].An early diagnosis biomarker that can measure brain cell degeneration due to AD would be valuable [2,[21][22][23]. But this may involve dealing with an extremely large number of individuals, as up to 50% of individuals with dementia may not have been diagnosed formally. Therefore, Simple, non-invasive, low-cost and reliable biomarkers are necessary for early diagnosis that can be accessed in clinical practice [5,24,25]. Recent guidelines support the use of biomarkers for biochemical and neuroimaging to promote AD diagnosis. AD testing of cerebral spinal fluid (CSF) is not commonly used in clinical practice as it involves lumbar puncture, an invasive procedure [2,26,27]. Neuroimaging is expensive, accessible only in specialized centers [28], and may ...

Entropy and Fractal Analysis of EEG Signals for Early Detection of Alzheimer's Dementia

“…Alzheimer's Dementia (AD), the most prevalent form of dementia globally, continues to experience a rise in its incidence [1]. This chronic, neurodegenerative condition, predominantly afflicting the elderly population, is marked by cognitive impairment and memory loss [2,3]. Despite not being directly lethal, AD's rapid progression significantly diminishes quality of life.…”

“…Biochemical modalities and medical imaging serve as standard biomarkers in AD diagnosis [3]. Biochemical modalities such as cerebrospinal fluid (CSF) are sensitive to pathological changes due to AD [8,9].…”

“…However, these medical modalities necessitate invasive procedures and find limited use in clinical practice. Medical imaging techniques, including MRI, CT-Scan, and FDG-PET [10,11], whilst sensitive to AD, are costly and typically available only in central hospitals [3].…”

Robust EEG Based Biomarkers to Detect Alzheimer’s Disease

“…AD affects numerous subcortical pathways in the brain [42] that lead to changes in the information-processing activity of the brain and these changes are thought to be reflected in the information content of the EEG [43][44][45]. Thus, EEG provides valuable information about changes in electrophysiological brain dynamics due to AD [43,[46][47][48][49]. EEG is non-invasive, low-cost, common, and has high sensitivity in discriminating between AD patients and normal elderly (Nold) subjects [50][51][52][53].…”