Neurodegenerative Diseases: An Overview of Environmental Risk Factors

Abstract

The population of the United States is aging, and an ever-increasing number of Americans are afflicted with neurodegenerative diseases. Because the pathogenesis of many of these diseases remains unknown, we must consider that environmental factors may play a causal role. This review provides an overview of the epidemiologic evidence for environmental etiologies for neurodegenerative diseases such as Alzheimer disease, Parkinson disease, parkinsonian syndromes (multiple system atrophy and progressive supranuclear palsy), and amyotrophic lateral sclerosis. Epidemiologic evidence for an association between environmental agents’ exposure and neurodegenerative diseases is not conclusive. However, there are indications that there may be causal links, and the need for more research is obvious.

Biomaterials for Enhancing Neuronal Repair

“…Unlike other systems in the human body, cues for growth and repair in the nervous system are no longer active post-developmentally and, consequently, structural and functional losses following disease or damage are catastrophic. Neurological deficits contribute to over 600 classified neurological disorders and affect ∼50 million people in the United States alone (Brown et al, 2005). Neurological disorders often result in debilitation rather than immediate death, and the personal and financial costs become staggering.…”

The olfactory vector hypothesis of neurodegenerative disease: Is it viable?

“…1 Thus, despite the fact that numerous genes have been identified for these two diseases, they usually relate to earlyonset familial forms and account for less than 10% of all cases. Although largely distinct phenotypically and pathologically, AD and PD exhibit identical olfactory dysfunction early in their course, 2 are often coexpressed, 3 share a number of common risk factors (eg, age, head trauma, the apolipoprotein ε4 gene), 1 and exhibit similar pathologies in brain regions such as the locus coeruleus. 4 Among environmental risk factors reported for AD and PD are viruses, aerosolized metals, and toxins.…”

“…4 Among environmental risk factors reported for AD and PD are viruses, aerosolized metals, and toxins. 1 Increased expression of ␤-amyloid (␤A) and indicators of brain inflammation have been found in the olfactory bulbs and other olfactory-related brain regions of people and dogs exposed to extreme air pollution, likely reflecting exposures to airborne particulates and aerosolized metals. 5 Previous occupational exposure to herbicides, as well as 20 or more years of occupational exposure to manganese (Mn), have been associated with 3-to 10-fold increased risks for development of PD.…”

Point-Of-Care Stem Cell Therapy (POCST): Multisite transplantation of autologous bone marrow-derived mononuclear cells in 85 patients with Amyotrophic Lateral Sclerosis improves survival

“…for the pathogenesis, however the etiologies are still undiscovered for the majority of patients [6].…”