The Role of Viruses in Neurodegenerative and Neurobehavioral Diseases

Abstract

Neurodegenerative and neurobehavioral diseases may be caused by chronic and neuropathic viral infections and may result in a loss of neurons and axons in the central nervous system that increases with age. To date, there is evidence of systemic viral infections that occur with some neurodegenerative conditions such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, autism spectrum disorders, and HIV-associated neurocognitive disorders. With increasing lifespan, the incidence of neurodegenerative diseases increases consistently. Neurodegenerative diseases affect approximately 37 million people worldwide and are an important cause of mortality. In addition to established non-viral-induced reasons for neurodegenerative diseases, neuropathic infections and viruses associated with neurodegenerative diseases have been proposed. Neuronal degeneration can be either directly or indirectly affected by viral infection. Viruses that attack the human immune system can also affect the nervous system and interfere with classical pathways of neurodegenerative diseases. Viruses can enter the central nervous system, but the exact mechanism cannot be understood well. Various studies have supported viral- and non-viral-mediated neurodegeneration at the cellular, molecular, genomic and proteomic levels. The main focus of this review is to illustrate the association between viral infections and both neurodegenerative and neurobehavioral diseases, so that the possible mechanism and pathway of neurodegenerative diseases can be better explained. This information will strengthen new concepts and ideas for neurodegenerative and neurobehavioral disease treatment.

A New Public Health Paradigm for Alzheimer's Disease Research

“…As with genetic research, virus infections that specifically and exclusively cause Alzheimer's disease have not been identified. But there is growing evidence that viruses are important in Alzheimer's disease and other neurological disorders [21]. The primary virus that we know causes dementia is HIV/AIDS.…”

Persistent EcoHIV infection induces nigral degeneration in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-intoxicated mice

“…First , influenza virus, herpes simplex virus, Epstein-Barr virus, cytomegalovirus, polio virus, HIV, West Nile virus, and Japanese encephalitis B viruses are known to be associated with PD (Jang et al , 2009). Second , each of these viruses is neurotropic, easily enters the brain, results in neural cell death, and elevates local pro-inflammatory cytokine production (Karim et al , 2014). Third , and opposing this view, are disease signs and symptoms which differ between HIV and PD (Boyd et al , 2016; Pakpoor et al , 2017).…”

Carbon Monoxide and Iron Modulate Plasmatic Coagulation in Alzheimer’s disease

“…Alzheimer's disease (AD) is a major source of morbidity and mortality for millions of people worldwide, and intense investigation has led to multiple etiological constructs contributing to AD [1][2][3][4][5][6][7][8][9][10][11][12]. In addition to the recently reviewed, original 'amyloid cascade hypothesis' [1], the development and progression of AD have been associated with viral infection [2], vascular damage from pulse pressure [3], regional deposition of metals, such as iron, resulting in oxidant injury [4][5][6][7][8], metabolic syndrome and morbid obesity [8][9][10], and long term exposure to spontaneous cerebral microemboli [11,12].…”

“…In addition to the recently reviewed, original 'amyloid cascade hypothesis' [1], the development and progression of AD have been associated with viral infection [2], vascular damage from pulse pressure [3], regional deposition of metals, such as iron, resulting in oxidant injury [4][5][6][7][8], metabolic syndrome and morbid obesity [8][9][10], and long term exposure to spontaneous cerebral microemboli [11,12]. Of these various paradigms, the notion that spontaneous emboli, most likely due to systemic hypercoagulability, is of particular interest.…”