title: Brain activation in high-functioning older adults and falls: Prospective cohort study.
abstract: OBJECTIVE
  To determine whether brain activity over the prefrontal cortex measured in real time during walking predicts falls in high-functioning older adults.
  
  
  METHODS
  We examined166 older persons (mean age 75 years, 51% women) enrolled in a prospective aging study. High-functioning status defined as the absence of dementia or disability with normal gait diagnosed by study clinicians. The magnitude of task-related changes in oxygenated hemoglobin levels over the prefrontal cortex was measured with functional near-infrared spectroscopy during motor (walking at normal pace) and cognitive (reciting alternate letters of the alphabet) single tasks and a dual-task condition (walking while reciting alternate letters of the alphabet). Incident falls were prospectively assessed over a 50-month study period.
  
  
  RESULTS
  Over a mean follow-up of 33.9 ± 11.9 months, 116 falls occurred. Higher levels of prefrontal cortical activation during the dual-task walking condition predicted falls (hazard ratio adjusted for age, sex, education, medical illnesses and general mental status 1.32, 95% confidence interval 1.03-1.70). Neither behavioral outcomes (velocity or letter rate) on the dual task nor brain activation patterns on the single tasks (normal walk or talk alone) predicted falls in this high-functioning sample. The results remained robust after accounting for multiple confounders and for cognitive status, slow gait, previous falls, and frailty.
  
  
  CONCLUSIONS
  Prefrontal brain activity levels while performing a cognitively demanding walking condition predicted falls in high-functioning seniors. These findings implicate neurobiological processes early in the pathogenesis of falls.
authors.affiliation: From the Departments of Neurology (J.V., E.A., R.H.), Medicine (J.V.), and Epidemiology (C.W.), Albert Einstein College of Medicine; Ferkauf Graduate School of Psychology (R.H.), Yeshiva University, Bronx, NY; and Drexel University School of Biomedical Engineering (M.I.), Philadelphia, PA. joe.verghese@einstein.yu.edu.
authors.forename: Joe
authors.initials: J
authors.lastname: Verghese
authors.affiliation: From the Departments of Neurology (J.V., E.A., R.H.), Medicine (J.V.), and Epidemiology (C.W.), Albert Einstein College of Medicine; Ferkauf Graduate School of Psychology (R.H.), Yeshiva University, Bronx, NY; and Drexel University School of Biomedical Engineering (M.I.), Philadelphia, PA.
authors.forename: Cuiling
authors.initials: C
authors.lastname: Wang
authors.affiliation: From the Departments of Neurology (J.V., E.A., R.H.), Medicine (J.V.), and Epidemiology (C.W.), Albert Einstein College of Medicine; Ferkauf Graduate School of Psychology (R.H.), Yeshiva University, Bronx, NY; and Drexel University School of Biomedical Engineering (M.I.), Philadelphia, PA.
authors.forename: Emmeline
authors.initials: E
authors.lastname: Ayers
authors.affiliation: From the Departments of Neurology (J.V., E.A., R.H.), Medicine (J.V.), and Epidemiology (C.W.), Albert Einstein College of Medicine; Ferkauf Graduate School of Psychology (R.H.), Yeshiva University, Bronx, NY; and Drexel University School of Biomedical Engineering (M.I.), Philadelphia, PA.
authors.forename: Meltem
authors.initials: M
authors.lastname: Izzetoglu
authors.affiliation: From the Departments of Neurology (J.V., E.A., R.H.), Medicine (J.V.), and Epidemiology (C.W.), Albert Einstein College of Medicine; Ferkauf Graduate School of Psychology (R.H.), Yeshiva University, Bronx, NY; and Drexel University School of Biomedical Engineering (M.I.), Philadelphia, PA.
authors.forename: Roee
authors.initials: R
authors.lastname: Holtzer
mesh_terms: D000058:Accidental Falls; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D010108:Oxyhemoglobins / Q000378:metabolism; D016016:Proportional Hazards Models; D012307:Risk Factors; D019265:Spectroscopy, Near-Infrared; D016138:Walking / Q000502:physiology*
chemical_list: D010108:Oxyhemoglobins