To determine whether gait and balance dysfunction are present in young urbanites exposed to fine particular matter PM 2.5 ≥ annual USEPA standard, we tested gait and balance with Tinetti and Berg tests in 575 clinically healthy subjects, age 21.0±5.7y who were residents in Metropolitan Mexico City, Villahermosa and Reynosa. The Montreal Cognitive Assessment was also applied to an independent cohort n:76, age 23.3± 9.1y. In the 575 cohort, 75.4% and 34.4% had abnormal total Tinetti and Berg scores and high risk of falls in 17.2% and 5.7% respectively. BMI impacted negatively Tinetti and Berg performance. Gait dysfunction worsen with age and males performed worse than females. Gait and balance dysfunction were associated with mild cognitive impairment MCI (19.73%) and dementia (55.26%) in 57/76 and 19 cognitively intact subjects had gait and balance dysfunction. Seventy-five percent of urbanites exposed to PM 2.5 had gait and balance dysfunction. For MMC residents-with historical documented Alzheimer disease (AD) and CSF abnormalities, these findings suggest Alzheimer Continuum is in progress. Early development of a Motoric Cognitive Risk Syndrome ought to be considered in city dwellers with normal cognition and gait dysfunction. The AD research frame in PM 2.5 exposed young urbanites should include gait and balance measurements. Multicity teens and young adult cohorts are warranted for quantitative gait and balance measurements and neuropsychological and brain imaging studies in high vs low PM 2.5 exposures. Early identification of gait and balance impairment in young air pollution-exposed urbanites would facilitate multidisciplinary prevention efforts for modifying the course of AD.

Millions of children across the world are exposed to multiple sources of indoor and outdoor air pollutants, including high concentrations of fine particulate matter (PM2.5) and ozone (O3). The established link between exposure to PM2.5, brain structural, volumetric and metabolic changes, severe cognitive deficits (1.5-2 SD from average IQ) in APOE 4 heterozygous females with >75 − < 94% BMI percentiles, and the presence of Alzheimer's disease (AD) hallmarks in urban children and young adults necessitates exploration of ways to protect these individuals from the deleterious neural effects of pollution exposure. Emerging research suggests that cocoa interventions may be a viable option for neuroprotection, with evidence suggesting that early cocoa interventions could limit the risk of cognitive and developmental concerns including: endothelial dysfunction, cerebral hypoperfusion, neuroinflammation, and metabolic detrimental brain effects. Currently, however, it is not clear how early we should implement consumption of cocoa to optimize its neuroprotective effects. Moreover, we have yet to identify suitable instruments for evaluating cognitive responses to these interventions in clinically healthy children, teens, and young adults. An approach to guide the selection of cognitive tools should take into account neuropsychological markers of cognitive declines in patients with Alzheimer's neuropathology, the distinct patterns of memory impairment between early and late onset AD, and the key literature associating white matter integrity and poor memory binding performance in cases of asymptomatic familial AD. We highlight potential systemic and neural benefits of cocoa consumption. We also highlight Working Memory Capacity (WMC) and attention control tasks as opened avenues for exploration in the air pollution scenario. Exposures to air pollutants during brain development have serious brain consequences in the short and long term and reliable cognition tools should be at hand to evaluate interventions.

Background: Quadruple aberrant hyperphosphorylated tau, amyloid-β, α-synuclein, and TDP-43 pathology had been documented in 202/203 forensic autopsies in Metropolitan Mexico City ≤40-year-olds with high exposures to ultrafine particulate matter and engineered nanoparticles. Cognition deficits, gait, equilibrium abnormalities, and MRI frontal, temporal, caudate, and cerebellar atrophy are documented in young adults. Objective: This study aimed to identify an association between falls, probable Rapid Eye Movement Sleep Behavior Disorder (pRBD), restless leg syndrome (RLS), and insomnia in 2,466 Mexican, college-educated volunteers (32.5±12.4 years). Methods: The anonymous, online study applied the pRBD and RLS Single-Questions and self-reported night-time sleep duration, excessive daytime sleepiness, insomnia, and falls. Results: Fall risk was strongly associated with pRBD and RLS. Subjects who fell at least once in the last year have an OR = 1.8137 [1.5352, 2.1426] of answering yes to pRBD and/or RLS questions, documented in 29% and 24% of volunteers, respectively. Subjects fell mostly outdoors (12:01 pm to 6:00 pm), 43% complained of early wake up hours, and 35% complained of sleep onset insomnia (EOI). EOI individuals have an OR of 2.5971 [2.1408, 3.1506] of answering yes to the RLS question. Conclusion: There is a robust association between falls, pRBD, and RLS, strongly suggesting misfolded proteinopathies involving critical brainstem arousal and motor hubs might play a crucial role. Nanoparticles are likely a significant risk for falls, sleep disorders, insomnia, and preventable neurodegenerative lethal diseases, thus characterizing air particulate pollutants’ chemical composition, emission sources, and cumulative exposure concentrations are strongly recommended.