The role of electromagnetic fields in neurological disorders
Murat Terzi, Berra Ozberk, Omur Gulsum Deniz, Suleyman Kaplan. The role of electromagnetic fields in neurological disorders. Journal of Chemical Neuroanatomy. Available online 12 April 2016.
Highlights
• Description of electromagnetic fields and evaluation of its possible effects on biological systems.
• The association between the electromagnetic field and neurodegenerative diseases.
• Experimental and clinical studies on the electromagnetic field.
Abstract
In the modern world, people are exposed to electromagnetic fields (EMFs) as part of their daily lives; the important question is “What is the effect of EMFs on human health?” Most previous studies are epidemiological, and we still do not have concrete evidence of EMF pathophysiology. Several factors may lead to chemical, morphological, and electrical alterations in the nervous system in a direct or indirect way. It is reported that non-ionizing EMFs have effects on animals and cells. The changes they bring about in organic systems may cause oxidative stress, which is essential for the neurophysiological process; it is associated with increased oxidization in species, or a reduction in antioxidant defense systems. Severe oxidative stress can cause imbalances in reactive oxygen species, which may trigger neurodegeneration. This review aims to detail these changes. Special attention is paid to the current data regarding EMFs’ effects on neurological disease and associated symptoms, such as headache, sleep disturbances, and fatigue.
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Excerpts
We suggest that neurodegenerative diseases are triggered by the high rate of protein synthesis in nerve cells, which the protein transport and distribution mechanism of the cell is not able to overcome. In neurodegenerative disease studies, cell degenerations have been researched that are explicable by this mechanism. Under these conditions, increased rates of protein synthesis in responsive nerve cells may be harmful to human health. These neurodegenerative effects have an underlying mechanism related to oxidative stress.
Oxidative stress is described as the increased production of oxidizing substances and a decrease in antioxidant defenses. In more intense cases of stress, necrosis can occur, as well as apoptosis (Lennon et al., 1991). In addition, in a lesser number of cases, the chemical reactions can be converted by transition metals or other redox cycling combines (containing quinones) through reduction, and as a result of this process, more aggressive radicals, which cause diffuse cellular damage, can occur. This process results in long-term DNA damage (Evans and Cooke, 2004). The immune system responds to the fatal effects of oxidants by making the increased production of radicals a central part of its mechanism of destroying pathogens, wherein induced phagocytes produce reactive oxygen species (ROS) and reactive nitrogen substances.
The damage in the host tissues is a result of these reactive complexes in the cytotoxic pathway of phagocytes. This prevents a pathogen from escaping this part of the immune response. It has been suggested that the mechanism of oxidant usage by the immune system, and an imbalance of oxidative stress, might explain the lack of an autoimmune neurological disease (Nathan and Shiloh, 2000).
High oxygen consumption in the brain results in overproduction of reactive oxygen species (ROS), which affects the nervous system. Additionally, neuronal membranes contain severe amounts of polyunsaturated fatty acids, which are susceptible to injury by free radicals.
... Most studies have shown that ROS may contribute to the down regulation of tight junctions and therefore induce the matrix metalloproteinases (MMP), accordingly, it plays a role in the blood–brain barrier (BBB). The BBB maintains an excessively stable extracellular environment, which is essential for certain synaptic transmissions and protects nervous sysem cells from damage. Increased impermeability of the BBB leads to potential hazards ....
There is evidence that the cell phone affects the BBB and induces headaches (Frey, 1998). Studies show that after EMF exposure, the permeability of the BBB changes, which may be due to the lack of autoimmune diseases’ effects on the CNS. BBB junctions become available to transmit immune cells, which may be a trigger for neuro-inflammation (de Vries et al., 1997).
Sensitivity to EMF exposure may be a common underlying effect in the CNS in regards to neurodegenerative disorders. In the literature, the main sensitization syndrome seems to be a pathophysiological change such as migraines, irritable bowel and bladder, fibromyalgia, chronic fatigue, or chronic pain. The IARC characterized the radiation of mobile phones as Group 2B (possibly carcinogenic) in 2011. Most studies show that the carcinogenic and genotoxic effects of EMFs also evidence a correlation between childhood leukemia and EMFs. However, there is still no definitive verdict on the link between EMFs and brain tumors. Some studies have demonstrated that neuro-endocrinological changes can cause neurological effects, such as cognitive affects. We now know that oxidative stress is caused by a lack of neurodegeneration, but the neurobehavioral effects pathway is still unknown.
.. based on data from in vivo and in vitro experimental studies, it has been suggested that the RF-EMF exposure has effects on neuronal activity and causes changes in cell excitability, cell membrane permeability, calcium efflux, and neurotransmitters (Volkow et al., 2011). Although there is a connection between EMFs and neurodegenerative disease, patients may suffer non-specific symptoms such as headaches, chronic fatigue, dizziness, sweating, paranoia, gastric distress, seizures, nausea, and chronic pain. People who do not have these symptoms may suffer from dark circles under the eyes, nerve pain, weakness, chronic illness, gastric disorder, and neurotransmitter imbalance. It is now known that these symptoms are also related to electromagnetic hypersensitivity.
... A 2011 review of neurological and oncological outcomes around mobile phone base stations showed that eight symptoms had increased prevalence, including headaches and sleep disorders (Khurana et al., 2010). However, the World Health Organization (WHO) made a decision in 2005 that there is no known scientific basis for saying that electromagnetic hypersensitivity is caused by exposure to an electromagnetic field. The prevalence of electromagnetic hypersensitivity ranges from a few cases per million people to 5% of the population, depending on the region and description of the condition (Levallois et al., 2002). It is difficult to determine the prevalence, as electromagnetic hypersensitivity is still an uncertain diagnosis. There is no specific analysis except for skin disorders, which are analyzed using subjective or non-specific methods; initially, all other causes of the same symptoms should be excluded.
Today, Alzheimer’s disease (AD) is the most common neurodegenerative disease and is characterized by the progressive loss of nervous system cells, especially in the cortex and hippocampus region. At the onset of the disease, oxidative injury is a key mechanism, progression, and pathogenesis. Specifically, redox-reactive metals (such as iron) are the main reason for hydroxyl radicals that are produced by redox reaction, and may support the synthesis of amyloid beta (Aβ) precursor protein, which is induced by oxidative stress (Stam, 2010; Fig. 2). We now have some information about the molecular principles of Alzheimer’s disease; however, its etiology is still unclear ....
The second most common neurodegenerative disease worldwide is Parkinson’s disease (PD). It occurs as a result of the death of dopaminergic neurons in the substantia nigra region of the brain (Fig. 3). Additionally, production of intracytoplasmic neuronal inclusions, such as α-synuclein, contributes to the onset of the degeneration process. Reaction of the Dopamine redox, and the α-synuclein mutation occurring in oxidative stress, are considered the main pathogenic factors of PD (Pollanen et al., 1993). It is suggested that oxidative injury to DNA, protein, lipids, and raised RNA oxidation play a key role in the loss of neurons. In contrast to the epidemiology of AD, there is insufficient supporting epidemiological data regarding a definite correlation between PD and EMFs exposure...
Amyotrophic lateral sclerosis (ALS) is also known as mortal neurodegenerative disorder. This progressive disease is characterized by the degeneration of motor neurons in the spinal cord, brain stem, and motor cortex. There is no inherited link in most ALS patients; however, a small number of patients have familial ALS in terms of the pathophysiology of the disease. Studies show that at a molecular level, antioxidant gene-encoding mutations may be responsible for the mechanism of degeneration. Oxidative stress is still indicated as having a key role. It must be considered that mitochondrial dysfunction may play a more important role in the etiopathogenesis of this disease than has hitherto been believed. Mitochondrial dysfunction may cause an energy deficit, whereby neurons are very sensitive. This triggers a calcium imbalance and initiates oxidative stress (Cozzolino and Carrì, 2012). Even though different hypotheses concerning the pathogenesis of the ALS have been promulgated, the etiology of most cases is unknown (Fig. 4) ....
Huntington’s disease (HD) is known as a progressive neurodegenerative disease; it transfers with genes and the autosomal dominant. The disorder starts with various psychiatric symptoms, cognitive regression, and choreiform movements. The Huntington protein is in the N-terminus of polyglutamine (Fig. 5). If cells have a repetition of the molecular genetic defect trinucleotide (CAG)n, they become excessive and the Huntington protein changes. Mutated genes cause neuronal cell death, particularly in the striatum and cortex. However, we still do not clearly understand the mechanisms of how they cause neuronal dysfunction and degeneration....
There is a great deal of controversy over the possible health effects of electromagnetic fields, and it is difficult to prove indisputably whether destructive risks exist or not. Although we still do not have much concrete evidence of exposure time and limit, it is best to keep public exposure well below the limits. High technology companies should find alternatives to comply with new environmental regulations. Future researchers should develop unique tools and experimental approaches to searching for living systems.
... In this review, synthesis studies on neurodegenerative disease, and some hypotheses, have shown evidence of a potential correlation between EMFs and the mechanism of neurodegeneration. Our knowledge of EMFs’ effects on the human brain is far from complete, and we also do not have enough evidence about peripheral neurological effects. Some people who are exposed to EMFs develop dysesthesia, but it is difficult to study nerve conduction in this disease in laboratory preparations. Overall, we do have some evidence from in vivo animals and in vitro cell and epidemiological studies that suggests that fetuses, infants, children, and adolescents, whose CNS is still developing and whose neuronal links are still forming, are more vulnerable to EMFs’ effects and demyelination.
It is necessary to conduct further research into the effects of EMFs on behavior, sleep, depression, cognitive activities, and psychomotor performance. In addition, the effects of prenatal and postnatal EMF exposure emitted by mobile phones can lead to attention problems in children. There is some evidence that EMFs can affect brain activity and the sleep cycle in humans. However, the health correlation is not clearly defined and studies cannot explain the precise mechanisms. Further studies of these effects are needed. Despite the fact we do not have enough evidence about the long-term neurological problems, these regions of science are significant in identifying the possible health effects. The largest amount of typical daily exposure comes from mobile phone base stations, cordless phones, and mobile phones. It is important to use these devices carefully. Cell phones play a significant part in our lives, although they remain harmful to human health, especially our brains. We recommend an increase in fully blinded, methodologically detailed studies on the biological and health effects of EMFs.
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