Clinical Neurophysiological and Automated EEG-Based Diagnosis of the Alzheimer's Disease

Shreya Bhat, U. Rajendra Acharya, Nahid Dadmehr, Hojjat Adeli
2015 European Neurology  
ability, and emotions and reduces the tempo of one's daily activities. Aging is not pathology but a normal physiological change leading to memory disorders. Dementia is a neurological disorder characterized by memory, language and cognitive impairment and loss in behavioral abilities. It is caused by brain cell death and worsens with age but is not linked to the typical aging process [1, 2] . Other potential causes of dementia are head injury, brain tumor, stroke, cerebral nervous system
more » ... on, vitamin deficiency, alcohol, exposure to heavy metals, and so on. Alzheimer's disease (AD) is the common basis of dementia in the elderly population [3] . AD is a progressive brain cell death and an irreversible process that happens over a course of time resulting in memory loss, inability to learn new things and perform calculations, unbalanced perception of space, depression, delusions and cognitive decline. These impairments hamper patients' social functioning and behavioral abilities [4, 5] . Cera et al. [6] studied the effect of AD on different cognitive functions such as orientation, language, attention, praxis, visual perception and executive function. They report that severity of language impairment and orofacial apraxias in the individuals with AD is directly proportional to the gradual progression of AD. The clinical features of AD are summarized in table 1 . Abstract Alzheimer's disease (AD) is a progressive disorder affecting intellectual, behavioral and functional abilities. It is associated with age and pathological alterations leading to the formation of amyloid plaques and tangles. It is the most common source of dementia in the older population, which varies in its degrees of severity. We are yet to find efficient methods of diagnosis of AD, as its symptoms vary among individuals. This paper presents a review of recent research on the clinical neurophysiological and automated electroencephalography-based diagnosis of the AD. Various therapeutic measures are also discussed briefly. AD is the sixth leading cause of death in the United States [7] . Patients die due to fall, malnutrition, dehydration, traumatic brain injury, and complications such as ab-ingestis pneumonia, pneumonia, bladder infection, and diabetes. AD often becomes fatal within 10 years of its commencement. According to the Alzheimer's Association, 13% of people over 65 years and 45% of people over 85 years have AD [8] . Some of the potential risk factors associated with AD are age, inheriting apolipoprotein E (APOE) gene [9] and sleep apnea [10] [11] [12] . Females are more prone to AD than males. AD progresses in prevalence after the age of 65. Prevalence rate increases by 2-fold every 5 years between the ages of 65 and 95. It rises from ∼ 2% in those aged 65-69, 4% in 70-74, 8% in 75-79, 16% in 80-85 and ∼ 35-40% over the age of 85 [13] . Neuro-researchers are trying to analyze possible age-related changes in the AD brain. Some of these changes include inflammation of the brain, atrophy, mitochondrial dysfunction and production of unstable molecules in the brain [13] . AD can also be inherited. Individuals with primary relative having AD show a 3-4fold increase in AD risk and it increases to a fold of 7.5 in individuals who have two or more primary relatives with AD [14] .
doi:10.1159/000441447 pmid:26588015 fatcat:jf6mvjtrerfjdkn6pqagsfqgde