Multifractals and Chronic Diseases of the Central Nervous System

TLDR: This chapter outlines the general description of the diseases like epilepsy, Parkinson’s, Huntington's, Alzheimer's, and motor neuron diseases, and a discussion on the diagnostic tools and the methodologies adapted is reviewed in detail.

Abstract: Disease of the central nervous system has been described in the literature as a group of neurological disorders for which the function of the brain or spinal cord is affected. This chapter outlines the general description of the diseases like epilepsy, Parkinson’s, Huntington’s, Alzheimer’s, and motor neuron diseases. Also a discussion on the diagnostic tools and the methodologies adapted is reviewed in detail. 1.1 Central Nervous System and Its Diseases The nervous system controls all activities of human beings. The nervous system consists of the brain and the spinal cord, as well as all the nerves throughout the body. Compared to other living organisms, humans are considered to be superior as the anatomy and physiology of the nervous system of humans are unique. The brain and spinal cord form the central nervous system (CNS), and all other nerves throughout the body are referred to as the peripheral nervous system (PNS). As the central nervous system (CNS) can determine the consciousness of us humans, it has been attributed to be the most complex organ in the human body. All aspects of our behavior from breathing to supporting our thoughts and feelings (Kandel and Squire 2000) are controlled by the nervous system. The human brain is the most sophisticated organ in the human body. The brain regulates vital body functions such as emotion, memory, cognition, motor activities, heart rate, respiration, and digestion. The human brain is a complex network of millions of neurons packed in a matrix of glial cells (Benson et al. 2017). Diseases of the brain may be caused either due to inherent dysfunction of the brain or due to complex interactions of the brain with the environment (Hyman et al. 2006). Brain diseases range widely from common neurological to psychiatric disorders. Throughout the life span, brain diseases affect a very significant portion of the population and are widely spread both across the developed and developing nations. Compared to other diseases, brain diseases account for the highest burden in terms of health, economy, and social capital globally (Nathan et al. 2001). More than 1.5 billion people are affected due to brain disorders worldwide, and with the passage of time, it is feared that this population will increase. Thus there is an urgent need of not © Springer Nature Singapore Pte Ltd. 2019 D. Ghosh et al., Multifractals and Chronic Diseases of the Central Nervous System, https://doi.org/10.1007/978-981-13-3552-5_1 1 only producing more drugs to treat CNS disorders but rigorous research so that early prognosis and diagnosis can be made and is the need of the day to help control this epidemic. Across the life span of human, the nature of the brain disorders changes. In young there is a high prevalence of psychiatric disorders, like depression, anxiety, schizophrenia, and substance abuse, whereas the elderly suffer markedly from neurodegenerative disorders such as dementia or stroke (Wittchen et al. 2011). More widely appreciated are the neurodegenerative disorders, namely, Parkinson’s (PD) and Alzheimer’s disease (AD), which are on the rise due to an older population (von Campenhausen et al. 2005). Huntington’s disease (HD) and amyotrophic lateral sclerosis (ALS) are other neurodegenerative diseases. The neurodegenerative diseases are characterized by inevitable gradual decline in cognitive ability and also the potential to self-sustain (Prince et al. 2013). The neurodegeneration produces a clinical syndrome called dementia, whose symptoms include inability to recollect, sudden and unexpected changes in one’s mood, and problems to communicate and reason (Devous 2002). Next to stroke, epilepsy is the second most common neurological disorder affecting approximately 50 million people worldwide. “Epilepsy” is derived from the Greek term epilambanein which means to seize, and it denotes the predisposition to have recurrent, unprovoked seizures (Quintero-Rincon et al. 2016). In epilepsy, the nerve cells of the brain transmit exorbitant electrical impulses that cause seizures. An epileptic seizure is defined as “a transient symptom of excessive or synchronous neuronal activity in the brain” (Fisher et al. 2005). Epilepsy is defined by two or more such unprovoked seizures. Seizures may be either focal or generalized. In focal seizures, only a specific segment of the brain is affected, while in generalized seizures the whole brain is affected (Acharya et al. 2012a). Epileptic seizures may lead to impairment or unconsciousness and psychic, autonomic, sensory, or motor problems (Lehnertz 2008). Electroencephalography (EEG) is an important clinical tool for monitoring and diagnosing neurological changes in epilepsy. Compared with other methods such as magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI), EEG is an affordable and safe technique for inspecting brain activity. Drugs and surgical treatment options are not sufficient to treat epilepsy. Among new therapies developed, implantable devices that deliver direct electrical stimulation to affected areas of the brain have shown promising results. The effectiveness of these treatments depends mainly on robust algorithms for seizure detection. As seizure onset cannot be predicted, a continuous recording of the EEG is essential to ascertain epilepsy. But since visual assessment of long EEG recordings is tedious and time-consuming (Song 2011), automated detection methods of epilepsy have gained importance. With a view to study the changes that occur in the brain in seizure and seizure-free status, we analyzed EEG signals using a latest state-of-theart methodology. The observations made are very interesting and are described in Chap. 2. Alzheimer’s disease another disease of the central nervous system is the major reason of dementia. This disease is described by an intensifying reduction in brain 2