LaRoche DP, Greenleaf BL, Croce RV, McGaughy JA.
Interaction of age, cognitive function, and gait performance in 50-80-year-olds. Age (Dordr). 2014;36 (4) :9693.
AbstractThe variability of walking gait timing increases with age and is strongly related to fall risk. The purpose of the study was to examine the interaction of age, cognitive function, and gait performance during dual-task walking. Forty-two, healthy men and women, 50-80 years old, completed the Mini-Mental State Exam (MMSE) and Trail Making Test (TMT) to assess cognitive performance and were separated into groups by decade of life. They then performed dual-task walking, at a self-selected pace, on an instrumented treadmill during three cognitive loading conditions: (1) no cognitive load, (2) subtraction from 100 by 1s, and (3) subtraction from 100 by 3s. The treadmill recorded spatiotemporal gait parameters that were used to calculate the mean and coefficient of variation for each variable over ten strides. Time to complete the TMT was positively correlated with age, stride time, double-limb support time, and mediolateral instability and was inversely correlated with single-limb support time. Subjects in their 70s increased their stride time and double-limb support time during the most challenging dual-task condition (subtraction by 3s), whereas subjects in their 50s and 60s did not. Across conditions, the variability of stride length, stride time, and single-limb support time was greatest in the 70s. Mediolateral instability increased only for subjects in their 70s in the subtraction by 3s condition. Reduced cognitive function with age makes it difficult for older adults to maintain a normal, rhythmical gait pattern while performing a cognitive task, which may place them at greater risk for falling.
Waber DP, Bryce CP, Fitzmaurice GM, Zichlin ML, McGaughy J, Girard JM, Galler JR.
Neuropsychological outcomes at midlife following moderate to severe malnutrition in infancy. Neuropsychology. 2014;28 (4) :530-40.
AbstractOBJECTIVE: To compare neuropsychological profiles of adults who had experienced an episode of moderate to severe protein-energy malnutrition confined to the first year of life with that of a healthy community comparison group.
METHOD: We assessed neuropsychological functioning in a cohort of Barbadian adults, all of whom had birth weight >2268 g. The previously malnourished group (N = 77, mean age = 38 years, 53% male) had been hospitalized during the first year of life for moderate to severe protein energy malnutrition and subsequently enrolled in a program providing nutrition education, home visits and subsidized foods to 12 years of age. They also had documented, adequate nutrition throughout childhood and complete catch-up in growth by the end of adolescence. The healthy comparison group (N = 59, mean age = 38 years, 54% male) were recruited as children from the same classrooms and neighborhoods.
RESULTS: Adjusted for effects of standard of living during childhood and adolescence and current intellectual ability level, there were nutrition group differences on measures of cognitive flexibility and concept formation, as well as initiation, verbal fluency, working memory, processing speed, and visuospatial integration. Behavioral and cognitive regulation were not affected.
CONCLUSIONS: Postnatal malnutrition confined to the first year of life is associated with neurocognitive compromise persisting into midlife. Early malnutrition may have a specific neuropsychological signature, affecting response initiation to a somewhat greater extent than response inhibition.
McGaughy JA, Amaral AC, Rushmore JR, Mokler DJ, Morgane PJ, Rosene DL, Galler JR.
Prenatal malnutrition leads to deficits in attentional set shifting and decreases metabolic activity in prefrontal subregions that control executive function. Dev Neurosci. 2014;36 (6) :532-41.
AbstractGlobally, over 25% of all children under the age of 5 years experience malnutrition leading to cognitive and emotional impairments that can persist into adulthood and beyond. We use a rodent model to determine the impact of prenatal protein malnutrition on executive functions in an attentional set-shifting task and metabolic activity in prefrontal cortex (PFC) subregions critical to these behaviors. Long-Evans dams were provided with a low (6% casein) or adequate (25% casein) protein diet 5 weeks before mating and during pregnancy. At birth, the litters were culled to 8 pups and fostered to control dams on the 25% casein diet. At postnatal day 90, prenatally malnourished rats were less able to shift attentional set and reverse reward contingencies than controls, demonstrating cognitive rigidity. Naive same-sexed littermates were assessed for regional brain activity using the metabolic marker (14)C-2-deoxyglucose (2DG). The prenatally malnourished rats had lower metabolic activity than controls in prelimbic, infralimbic, anterior cingulate, and orbitofrontal cortices, but had comparable activity in the nearby piriform cortex and superior colliculus. This study demonstrates that prenatal protein malnutrition in a well-described animal model produces cognitive deficits in tests of attentional set shifting and reversal learning, similar to findings of cognitive inflexibility reported in humans exposed to early childhood malnutrition.
Waber DP, Bryce CP, Fitzmaurice GM, Zichlin ML, McGaughy J, Girard JM, Galler JR.
Neuropsychological outcomes at midlife following moderate to severe malnutrition in infancy. Neuropsychology. 2014;28 :530-40.
AbstractOBJECTIVE: To compare neuropsychological profiles of adults who had experienced an episode of moderate to severe protein-energy malnutrition confined to the first year of life with that of a healthy community comparison group. METHOD: We assessed neuropsychological functioning in a cohort of Barbadian adults, all of whom had birth weight >2268 g. The previously malnourished group (N = 77, mean age = 38 years, 53% male) had been hospitalized during the first year of life for moderate to severe protein energy malnutrition and subsequently enrolled in a program providing nutrition education, home visits and subsidized foods to 12 years of age. They also had documented, adequate nutrition throughout childhood and complete catch-up in growth by the end of adolescence. The healthy comparison group (N = 59, mean age = 38 years, 54% male) were recruited as children from the same classrooms and neighborhoods. RESULTS: Adjusted for effects of standard of living during childhood and adolescence and current intellectual ability level, there were nutrition group differences on measures of cognitive flexibility and concept formation, as well as initiation, verbal fluency, working memory, processing speed, and visuospatial integration. Behavioral and cognitive regulation were not affected. CONCLUSIONS: Postnatal malnutrition confined to the first year of life is associated with neurocognitive compromise persisting into midlife. Early malnutrition may have a specific neuropsychological signature, affecting response initiation to a somewhat greater extent than response inhibition.