A population-based study on brain atrophy and motor performance in elderly women

Relationship of Neural Correlates of Gait Characteristics and Cognitive Dysfunction in Patients with Mild Cognitive Impairment

Background: Some patients with mild cognitive impairment (MCI) experience gait disturbances. However, there are few reports on the relationship between gait disturbance and cognitive function in patients with MCI. Therefore, we investigated the neural correlates of gait characteristics related to cognitive dysfunction. Methods: Eighty patients diagnosed with MCI from three dementia centers in Gangwon-do, Korea, were recruited for this study. We defined MCI as a Clinical Dementia Rating global score of 0.5 or higher, with a memory domain score of 0.5 or greater. The patients were classified as having either higher or lower MMSE and the groups were based on their Mini Mental Status Examination z-scores. Multiple logistic regression analysis was performed to examine the association between the gait characteristics and cognitive impairment. Analyses included variables such as age, sex, years of education, number of comorbidities, body mass index, and height. Results: Gait velocity, step count, step length, heel-to-heel base support, swing and stance phase duration, and support time were associated with cognitive function. A decrease in gray matter volume in the right pericalcarine area was associated with gait characteristics related to cognitive dysfunction. An increase in the curvature of gray matter in the right entorhinal, right lateral orbitofrontal, right cuneus, and right and left pars opercularis areas was also associated with gait characteristics related to cognitive dysfunction. Conclusion: Since gait impairment is an important factor in determining activities of daily living in patients with mild cognitive impairment, the evaluation of gait and cognitive functions in patients with mild cognitive impairment is important.

Brain CT can predict low lean mass in the elderly with cognitive impairment: a community-dwelling study

Background

The coexistence of sarcopenia and dementia in aging populations is not uncommon, and they may share common risk factors and pathophysiological pathways. This study aimed to evaluate the relationship between brain atrophy and low lean mass in the elderly with impaired cognitive function.

Methods

This cross-sectional study included 168 elderly patients who visited the multi-disciplinary dementia outpatient clinic at Kaohsiung Chang Gung Memorial Hospital for memory issues, between 2017 and 2019. The body composition was assessed by dual energy X-ray absorptiometry (DEXA) and CT based skeletal muscle index including L3 skeletal muscle index (L3SMI) and masseter muscle mass index (MSMI). The brain atrophy assessment was measured by CT based visual rating scale. Possible predictors of low lean mass in the elderly with cognitive impairement were identified by binary logistic regression. ROC curves were generated from binary logistic regression.

Results

Among the 81 participants, 43 (53%) remained at a normal appendicular skeletal muscle index (ASMI), whereas 38 (47%) showed low ASMI. Compared with the normal ASMI group, subjects with low ASMI exhibited significantly lower BMI, L3SMI, and MSMI (all p < 0.05), and showed significant brain atrophy as assessed by visual rating scale (p < 0.001). The accuracy of predictive models for low ASMI in the elderly with cognitive impairment were 0.875, (Area under curve (AUC) = 0.926, 95% confidence interval [CI] 0.844–0.972) in model 1 (combination of BMI, GCA and L3SMI) and 0.885, (Area under curve (AUC) = 0.931, [CI] 0.857–0.979) in model 2 (combination of BMI, GCA and MSMI).

Conclusions

Global cortical atrophy and body mass index combined with either L3 skeletal muscle index or masseter skeletal muscle index can predict low lean mass in the elderly with cognitive impairment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02626-8.

Voluntary wheel running delays brain atrophy in aged mice

BACKGROUND:

Physical exercises have been shown to be a surprisingly effective strategy to take advantage of the brain’s natural capacity for plasticity, and prevent brain degeneration in mouse histological studies. In vivo magnetic resonance microscopy (MRM) provides highly resolved anatomical images and allows quantitative assessment of brain atrophy in the aged mouse model.

OBJECTIVE:

The aim of the present study was to investigate, through the effects of 10 weeks voluntary wheel running, the mouse’s brain atrophy.

METHODS:

Sixteen C57BL/6J mice, aged 21 months, were randomized to the exercise or sedentary group. Each mouse was scanned in a 7.0-T MRM scanner at two time points: 22 months old baseline and a follow-up three months later. Multi-atlas based brain segmentation approach was used to obtain volumes of 39 brain regions.

RESULTS:

The results showed that mice in the exercise group had less brain atrophy compared with the mice in the sedentary group.

CONCLUSIONS:

The results provide new insights into exercise induced brain plasticity in aged animals.

Brain structural change and gait decline: a longitudinal population-based study

OBJECTIVES

To investigate longitudinal associations between changes in brain structure and gait decline.

DESIGN

Longitudinal.

SETTING

Population-based Tasmanian Study of Cognition and Gait.

PARTICIPANTS

Two hundred twenty-five individuals aged 60 to 86 (mean age 71.4 ± 6.8) randomly selected from the electoral roll with baseline and follow-up data.

MEASUREMENTS

Volumes of gray matter, white matter, hippocampi, and white matter lesions (WML) were estimated using automated segmentation from magnetic resonance imaging (MRI). Gait variables were measured using a computerized walkway. Linear regression was used to estimate the association between change in brain MRI measures and change in gait. Time between measurements, age, sex, BMI, education level, total intracranial volume, baseline infarcts, and medical history were used as baseline covariates.

RESULTS

Mean follow-up was 30.6 months. White matter atrophy was associated with a decline in gait speed (P = .001), step length (P = .005), and cadence (P = .001). WML progression was associated with a decline in gait speed (P = .04), and its association with decline in step length was stronger with greater baseline age (P for interaction = .04). Hippocampal atrophy was associated with a decline in gait speed (P = .006) and step length (P = .001). Total gray matter atrophy was associated with decline in cadence in those with cerebral infarcts (P for interaction = .02).

CONCLUSION

These are the first longitudinal data demonstrating the relative contributions of brain atrophy and WML progression to gait decline in older people. Effect modification according to age and infarcts suggests a contribution of reduced physiological and brain reserve. Interventions targeting brain health may be important in preventing mobility decline in older people.

Slow gait in MCI is associated with ventricular enlargement: results from the Gait and Brain Study

Slow gait is ubiquitous among older adults and predicts cognitive decline and progression to dementia. Age-related structural brain changes could be responsible for abnormal gait. The purpose of this study was to determine whether brain lateral ventricle volume, a measure of brain atrophy, was associated with gait velocity among older adults with mild cognitive impairment (MCI), while considering the effects of age and brain vascular burden. Twenty community-dwellers with MCI, free of hydrocephalus, aged 76 years (69/80) [median (25th/75th percentile)] (35 % female) from the 'Gait and Brain Study' were included in this analysis. Quantitative gait performance was measured while steady-state walking at self-selected pace with a 6-m electronic portable walkway (GAITRite). Brain ventricle volume was quantified using semi-automated software from three-dimensional T1-weighted magnetic resonance imaging. Age, white matter hyperintensity burden and Mini-Mental State Examination score were used as potential confounders. Median gait velocity was 118.7 cm/s (104.4/131.3). Median brain ventricle volume was 39.9 mL (30.0/46.6) with the left ventricle being slightly larger than the right (P = 0.052). Brain ventricle volume was inversely associated with gait velocity (adjusted β = -0.63, P = 0.046). Volume of both the ventricular main bodies and the temporal horns correlated inversely with gait velocity (respectively, P = 0.009, P = 0.008). Left ventricle volume correlated with decreased gait velocity (P = 0.002) while right ventricle did not (P = 0.068). Slower gait velocity was associated with larger brain ventricle volume in our sample of people with MCI independent of age, cerebrovascular burden and cognitive worsening. This result may help elucidate the trajectories of cognitive and gait declines in people with MCI.

MRI atrophy of the caudate nucleus and slower walking speed in the elderly

Cerebral white matter lesions are associated with poorer motor performances in the elderly, but the role of gray matter atrophy remains largely unknown. We investigated the cross-sectional relation between brain regional gray matter volumes and walking speed over 6m in the 3C-Dijon study, a large population-based study of community-dwelling persons aged 65 years and over (N=1623). Regional gray matter volumes were obtained using an automated anatomical labeling parcellation method. Multivariable analyses were performed using a semi-Bayes approach. After adjustment for potential confounders, persons who walked slower had a smaller volume of basal ganglia (regression coefficient [β]=0.054, standard error [SE]=0.028, p=0.05). In more detailed analyses, the volume of the caudate nucleus had a preponderant role on this association (β=0.049, SE=0.019, p=0.009), and walking speed decreased progressively with the volume of the caudate nucleus (p for linear trend<0.001). These results underline the role of gray matter subcortical structures, in particular of the caudate nucleus, in the age-related decline of motor performances among community-dwelling elderly subjects.

Upper and lower extremity motor function and cognitive impairment in multiple sclerosis

Motor impairments and cognitive dysfunction are common in multiple sclerosis (MS). We aimed to delineate the relationship between cognitive capacity and upper and lower motor function in 211 MS patients, and 120 healthy volunteers. Lower and upper motor function were assessed with the Timed 25 Foot Walk (T25FW) and the Nine Hole Peg Test (NHPT) as implemented in the Multiple Sclerosis Functional Composite (MSFC). Subjects also underwent neuropsychological evaluation. Hierarchical linear regression analysis was conducted separately for the MS and healthy groups with the T25FW and NHPT serving as the outcome measures. Cognitive performance indices served as predictors. As expected, healthy subjects performed better than the MS group on all measures. Processing speed and executive function tests were significant predictors of lower and upper motor function in both groups. Correlations were more robust in the MS group, where cognitive tests predicted variability in motor function after controlling for disease duration and physical disability. In conclusion, we find evidence of higher order cognitive control of motor function that appears to be particularly salient in this large and representative MS sample. The findings may have implications for risk assessment and treatment of mobility dysfunction in MS.

High blood pressure accelerates gait slowing in well-functioning older adults over 18-years of follow-up

OBJECTIVES

To examine whether the association between hypertension and decline in gait speed is significant in well-functioning older adults and whether other health-related factors, such as brain, kidney, and heart function, can explain it.

DESIGN

Longitudinal cohort study.

SETTING

Cardiovascular Health Study.

PARTICIPANTS

Of 2,733 potential participants with a brain magnetic resonance imaging (MRI) scan, measures of mobility and systolic blood pressure (BP), no self-reported disability in 1992 to 1994 (baseline), and with at least 1 follow-up gait speed measurement through 1997 to 1999, 643 (aged 73.6, 57% female, 15% black) who had received a second MRI in 1997 to 1999 and an additional gait speed measure in 2005 to 2006 were included.

MEASUREMENTS

Mixed models with random slopes and intercepts were adjusted for age, race, and sex. Main explanatory factors included white matter hyperintensity progression, baseline cystatin-C, and left cardiac ventricular mass. Incidence of stroke and dementia, BP trajectories, and intake of antihypertensive medications during follow-up were tested as other potential explanatory factors.

RESULTS

Higher systolic BP was associated with faster rate of gait speed decline in this selected group of 643 participants, and results were similar in the parent cohort (N = 2,733). Participants with high BP (n = 293) had a significantly faster rate of gait speed decline than those with baseline BP less than 140/90 mmHg and no history of hypertension (n = 350). Rates were similar for those with history of hypertension who were uncontrolled (n = 110) or controlled (n = 87) at baseline and for those who were newly diagnosed (n = 96) at baseline. Adjustment for explanatory factors or for other covariates (education, prevalent cardiovascular disease, physical activity, vision, mood, cognition, muscle strength, body mass index, osteoporosis) did not change the results.

CONCLUSION

High BP accelerates gait slowing in well-functioning older adults over a long period of time, even for those who control their BP or develop hypertension later in life. Health-related measurements did not explain these associations. Future studies to investigate the mechanisms linking hypertension to slowing gait in older adults are warranted.

A population-based study on the influence of brain atrophy on 20-year survival after age 85

BACKGROUND

Individuals aged 80 years and older is the fastest growing segment of the population worldwide. To understand the biology behind increasing longevity, it is important to examine factors related to survival in this age group. The relationship between brain atrophy and survival after age 85 remains unclear.

METHODS

A population-based sample (n = 239) had head CT scans at age 85 and was then followed until death. Cortical atrophy and ventricular size were assessed. Statistical analyses included Cox proportional hazards models with time to death as the outcome and considering a large number of possible confounders, including baseline cognitive function, incident dementia, and somatic disorders.

RESULTS

Mean survival time (±SD) was 5.0 ± 3.6 years (range 0.10-19.8 years). Decreased survival was associated with temporal, and frontal atrophy, sylvian fissure width and a number of ventricular measures after adjustment for potential confounders. In participants without dementia at baseline (n = 135), decreased survival was associated with temporal lobe atrophy and bifrontal ratio. In those with dementia (n = 104), decreased survival was associated with third ventricle width, cella media ratio, and ventricle-to-brain and ventricle-to-cranial ratio.

CONCLUSIONS

Several indices of brain atrophy were related to decreased survival after age 85, regardless of dementia status. Brain atrophy is rarely mentioned as a significant indicator of survival in the elderly, independent of traditional predictors such as cardiovascular disease or cancer. The biology behind the influence of brain atrophy on survival needs to be further scrutinized.

A new automated implementation of the Posturo-Locomotion-Manual (PLM) method for movement analysis in patients with parkinson's disease

OBJECTIVE

The Posturo-Locomotion-Manual (PLM) test, which uses an optoelectronic laboratory system, has here been further developed into an automated, more user-friendly, standardized tool for movement analysis named the QbTestMotus. This paper compares the accuracy of QbTestMotus to the PLM test, in particular the automated data analysis.

METHODS

Both QbTestMotus and the PLM recorded data simultaneously from the same 61 patients. The correlation coefficients of movement time (MT), postural time (P), locomotion time (L), and manual time (M) were calculated between the systems. The absolute differences between the result parameters for each patient were also studied. Finally, the differences in MT between the systems were compared with the positive responses in the levodopa (L-dopa) challenges as measured in the PLM test for 11 patients.

RESULTS

The comparisons in all the 61 patients showed high correlation coefficients for all four parameters. The absolute differences between the parameters were small and had small standard deviations, and the decreases in MT because of L-dopa in the positive L-dopa responders were much larger than the absolute difference between the systems.

CONCLUSION

The PLM test and QbTestMotus are equivalent along all parameters, thus indicating that the test quality is equivalent between the PLM test and the automated QbTestMotus system.

Association between executive function and physical performance in older Korean adults: findings from the Korean Longitudinal Study on Health and Aging (KLoSHA)

Reduced executive function and physical performance are common age-related conditions. This study evaluated the associations between executive function and physical performance in a representative sample of older adults. Cross-sectional data were analyzed from a population-based sample of 629 men and women aged 65 or older and living in one typical city in Korea. Specific aspects of executive function were assessed using the trail making test, digit span test, and lexical fluency test to measure set shifting, working memory and cognitive flexibility functions. Physical performance was measured using performance-oriented mobility assessment (POMA) scores and isokinetic muscle strength. Subjects' self-efficacy was also assessed using the activities-specific balance confidence (ABC) scale. Results of the lexical fluency test were associated with POMA scores and muscle strength, independent of age, gender, education, comorbidity, physical activity status, depression, and global cognition, suggesting that reduced cognitive flexibility is associated with reduced physical performance and muscle strength. Self-efficacy was also independently associated with physical performance and muscle strength. Clinicians need to consider the association between executive function and physical performance when working to improve physical functioning in an aged population.

Lower-extremity function in cognitively healthy aging, mild cognitive impairment, and Alzheimer's disease

OBJECTIVE

To examine differences in lower-extremity function in cognitive healthy older persons, older persons with mild cognitive impairment (MCI), and older persons with Alzheimer's disease (AD).

DESIGN

Descriptive study.

SETTING

University Alzheimer's disease clinical and research program.

PARTICIPANTS

Older persons (N=66) were studied (mean age, 76.7y); 22 were cognitively normal, 22 were diagnosed with probable MCI, 22 were diagnosed with probable AD.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Lower-extremity function was assessed by the four-meter walk test (4MWT), Timed Up & Go (TUG) test, and sit-to-stand (STS) test.

RESULTS

Analysis of variance, adjusting for covariates, revealed that performance on the 4MWT was significantly lower in the MCI and AD groups as compared with controls. TUG test performance was worse in the AD group compared with controls. No significant group differences were found for STS performance.

CONCLUSIONS

These results suggest an association between cognitive impairment and lower-limb function in older persons. Walking speed could be evaluated for its possible utility in screening older persons at risk for cognitive impairment and falls.

Brain aging and gait

Aging is associated with a reduction in several functions including gait. The preservation of gait is important in order to prevent falls and consequent injury as one gets older. Poorer gait may also be an important marker for health status and a determinant of quality of life in later life. It is now recognized that specific regions of the brain such as the frontal motor, prefrontal and parietal cortices, the basal ganglia and cerebellum play an important role in the initiation, planning, execution and maintenance of gait, in tandem with other neuromuscular factors. Aging and age-related disease may affect areas of the brain that are involved in the regulation of gait. Recent technological advances in brain imaging have enabled the identification of age-related changes occurring in the brain, such as cortical atrophy, brain infarctions or cerebral white matter lesions. There is a small, but growing, amount of research examining the association between these changes and gait. The objective of this review is to summarize the current state of knowledge on the impact of the aging brain on gait, and to identify directions for future research. Such research may lead to the development of interventions aimed at preventing or reducing the effect of brain aging on gait.

Gait speed under varied challenges and cognitive decline in older persons: a prospective study

OBJECTIVE

to examine whether usual gait speed, fast gait speed or speed while walking with a cognitive or neuromuscular challenge predicts evolving cognitive decline over 3 years.

DESIGN

prospective study.

SETTING

population-based sample of community-dwelling older persons.

PARTICIPANTS

660 older participants (age > or = 65 years).

MEASUREMENTS

usual gait speed, fastest gait speed, gait speed during 'walking-while-talking', depression, comorbidities, education, smoking and demographics were assessed at baseline. Cognition was evaluated at baseline and follow-up. A decline in MMSE score by > or = 3 points was considered as significant cognitive decline (SCD).

RESULTS

adjusting for confounders, only fast speed was associated with cognitive performance at 3-year follow-up. One hundred thirty-five participants had SCD over 3 years. Participants in the lowest quartile of usual speed or walking-while-talking speed were more likely to develop SCD. Conversely, participants in the third and fourth quartiles of fast speed were more likely to develop SCD. J-test showed that the model including fast speed quartiles as a regressor was significantly more predictive of SCD than the models with usual speed or walking-while-talking speed quartiles.

CONCLUSION

measuring fast gait speed in older persons may assist in identifying those at high risk of cognitive decline.

MRI- and MRS-derived hippocampal correlates of quantitative locomotor function in older adults

Gait measures have been shown to predict cognitive decline and dementia in older adults. Investigation of the neurobiology associated with locomotor function is needed to elucidate this relationship with cognitive abilities. This study aimed to examine magnetic resonance imaging (MRI; hippocampal volume)- and proton magnetic resonance spectroscopy (MRS; N-acetylaspartate to creatine (NAA/Cr) ratios)-derived hippocampal correlates of quantitative gait function (swing time (seconds), stride length (cm), and stride length variability (standard deviation)) in a subset of 48 nondemented older adults (24 males; mean age=81 years) drawn from the Einstein Aging Study, a community-based sample of individuals over the age of 70 residing in Bronx, New York. Linear regression analyses controlling for age were used to examine hippocampal volume and neurochemistry as predictors of gait function. We found that stride length was associated with hippocampal volume (beta=0.36, p=0.03; overall model R(2)=0.33, p=0.01), but not hippocampal neurochemistry (beta=0.09, p=0.48). Stride length variability was more strongly associated with hippocampal NAA/Cr (beta=-0.38, p=0.01; overall model R(2)=0.14, p=0.04) than hippocampal volume (beta=-0.33, p=0.08). Gait swing time was not significantly related to any neuroimaging measure. These relationships remained significant after accounting for memory and clinical gait impairments. These findings suggest that nondemented older adults exhibit increased stride length variability that is associated with lower levels of hippocampal neuronal metabolism, but not hippocampal volume. Conversely, decreased stride length is associated with smaller hippocampal volumes, but not hippocampal neurochemistry. Distinct neurobiological hippocampal substrates may support decreased stride length and increased stride length variability in older adults.

Cognitive status and physical function in older african americans

OBJECTIVES

To investigate the relationship between global cognition, three specific domains of cognition, and lower extremity function in community-dwelling elderly African Americans (AAs) from two community settings.

DESIGN

Cross-sectional study.

SETTING

Community.

PARTICIPANTS

Ninety-six AA men and women aged 60 and older from two community settings, enrolled in the Boosting Minority Involvement (BMI) study, a community-based cohort study designed to increase research participation of older low-income AAs.

MEASUREMENTS

Physical performance was assessed using Short Physical Performance Battery score, which is composed of three timed tests: a 4-m walking task, static balance assessment, and a chair stand test. The Bushke Memory Impairment Screen (MIS) and Mini-Mental State Examination were used to assess global memory and global cognition, respectively. For domain-specific performance, three z-score composite scores (attention, verbal memory, and executive function) were developed using the Computer-based Assessment of Mild Cognitive Impairment.

RESULTS

All domains of cognition were significant predictors of lower extremity function except for verbal memory. Executive function and MIS were the best predictors of lower extremity function in adjusted models. Participants with poor executive function were more than four times as likely to have poorer lower extremity function (odds ratio=4.96, 95% confidence interval=1.07-23.0).

CONCLUSION

Global memory and executive function were the best predictors of lower extremity function in a sample of community-dwelling AA adults. Deficits in lower extremity function may depend on multifaceted higher executive function control processes.

Gait dysfunction in mild cognitive impairment syndromes

OBJECTIVES

To conduct a systematic clinical and quantitative assessment of gait in older adults with mild cognitive impairment (MCI) syndromes.

DESIGN

Cross-sectional.

SETTING

Einstein Aging Study, a community-based longitudinal aging study.

PARTICIPANTS

Fifty-four individuals with amnestic MCI (a-MCI), 62 with nonamnestic-MCI (na-MCI), and 295 healthy controls identified from the Einstein Aging Study participants.

MEASUREMENTS

Comparison of clinical and quantitative gait performance in subjects with MCI subtypes with that of cognitively normal older adults.

RESULTS

Neurological gaits were more common in a-MCI (31.5%, P=.008) but not in na-MCI (19.4%, P=.55), than in controls (16.3%). Quantitative gait in multiple parameters was worse in both MCI subtypes than in controls. Factor analysis revealed three independent factors representing pace, rhythm, and variability. Subjects with a-MCI had worse rhythm and variability scores than those with na-MCI and controls. Subjects with na-MCI had worse performance on the pace domain than the other two groups. Subjects with MCI and gait abnormalities had higher disability scores than subjects with MCI without gait abnormalities.

CONCLUSION

Gait dysfunction is common in older individuals with amnestic and nonamnestic subtypes of MCI.

Gait, aging and dementia

Cognitive impairment has been recognized as a risk factor for falls and for increasing the severity of injury following a fall, but the mechanisms by which cognitive impairment influences gait and postural control have been unclear. A recent report that galantamine improves gait parameters in older adults may help to untangle this.

The relationship between specific cognitive functions and falls in aging

The current study examined the relationship between cognitive function and falls in older people who did not meet criteria for dementia or mild cognitive impairment (N = 172). To address limitations of previous research, the authors controlled for the confounding effects of gait measures and other risk factors by means of associations between cognitive function and falls. A neuropsychological test battery was submitted to factor analysis, yielding 3 orthogonal factors (Verbal IQ, Speed/Executive Attention, Memory). Single and recurrent falls within the last 12 months were evaluated. The authors hypothesized that Speed/Executive Attention would be associated with falls. Additionally, the authors assessed whether associations between different cognitive functions and falls varied depending on whether single or recurrent falls were examined. Multivariate logistic regressions showed that lower scores on Speed/Executive Attention were associated with increased risk of single and recurrent falls. Lower scores on Verbal IQ were related only to increased risk of recurrent falls. Memory was not associated with either single or recurrent falls. These findings are relevant to risk assessment and prevention of falls and point to possible shared neural substrates of cognitive and motor function.

Quantitative gait dysfunction and risk of cognitive decline and dementia

BACKGROUND

Identifying quantitative gait markers of preclinical dementia may lead to new insights into early disease stages, improve diagnostic assessments and identify new preventive strategies.

OBJECTIVE

To examine the relationship of quantitative gait parameters to decline in specific cognitive domains as well as the risk of developing dementia in older adults.

METHODS

We conducted a prospective cohort study nested within a community based ageing study. Of the 427 subjects aged 70 years and older with quantitative gait assessments, 399 were dementia-free at baseline.

RESULTS

Over 5 years of follow-up (median 2 years), 33 subjects developed dementia. Factor analysis was used to reduce eight baseline quantitative gait parameters to three independent factors representing pace, rhythm and variability. In linear models, a 1 point increase on the rhythm factor was associated with further memory decline (by 107%), whereas the pace factor was associated with decline on executive function measured by the digit symbol substitution (by 29%) and letter fluency (by 92%) tests. In Cox models adjusted for age, sex and education, a 1 point increase on baseline rhythm (hazard ratio (HR) 1.48; 95% CI 1.03 to 2.14) and variability factor scores (HR 1.37; 95% CI 1.05 to 1.78) was associated with increased risk of dementia. The pace factor predicted the risk of developing vascular dementia (HR 1.60; 95% CI 1.06 to 2.41).

CONCLUSION

Our findings indicate that quantitative gait measures predict future risk of cognitive decline and dementia in initially non-demented older adults.

Cognitive processes related to gait velocity: results from the Einstein Aging Study

The authors examined the relationship between cognition and gait velocity, performed with and without interference, in elderly participants. Neuropsychological test scores from 186 cognitively normal elders were submitted to factor analysis that yielded 3 factors: Verbal IQ, Speed/Executive Attention, and Memory. Regression analyses revealed that these factors were significant predictors of variance in gait velocity, but the relationship varied as a function of task condition. All 3 factors predicted gait velocity without interference. However, the Speed/Executive Attention and Memory factors but not Verbal IQ predicted gait velocity in the interference condition. These findings suggest that gait velocity and cognitive function may have both shared and independent brain substrates. Future studies should explore gait velocity and cognitive function as predictors of dementia and falls.

Quantitative Measures of Gait Characteristics Indicate Prevalence of Underlying Subclinical Structural Brain Abnormalities in High-Functioning Older Adults

Abnormal gait in high-functioning older adults may indicate underlying subtle structural brain abnormalities. We tested the hypothesis that temporal and spatial parameters of gait, including speed, stride length and double support time, are cross-sectionally associated with white matter hyperintensity, subcortical infarcts or brain atrophy on brain MRI. We examined 321 men and women (mean age = 78.3) participating to the Cardiovascular Health Study who were free of dementia or stroke at the time of the gait assessment. Analyses were set with gait as independent variable and brain MRIs as dependent variables. Gait measures were determined from the footfalls recorded on a 4-meter-long instrumented walking surface, the GaitMat II. Brain MRIs were examined for the presence of white matter hyperintensity (WMG, graded from 0 to 9), brain infarcts (predominantly subcortical) and ventricular enlargement (graded from 0 to 9). Slower gait, shorter stride length and longer double support times were associated with greater prevalence of white matter grade > or =3 (p = 0.02), and at least 1 brain infarct (p = 0.04) independent of age. In multivariate logistic regression models adjusted for demographics and clinical cardiovascular diseases, those with gait speed <1.02 m/s were more likely to have WMG > or =3 and at least 1 brain infarct, compared with those with faster gait - odds ratio (OR): 2.85, 95% confidence interval (95% CI): 1.35, 6.02, and OR: 2.09, 95% CI: 1.04, 4.19. Shorter stride length was also associated with greater probability of having at least 1 brain infarct (gait stride <0.88 vs. >1.10 m: OR: 3.20, 95% CI: 1.49, 6.88), while longer double support times were associated with a greater probability of having WMG > or =3 (double support time >0.19 vs. <0.14 s: OR: 2.3, 95% CI: 1.1, 4.7) independent of demographics and clinical cardiovascular diseases. Gait parameters were not significantly associated with ventricular grade. In summary, in this group of high-functioning older adults, poorer gait speed, shorter stride and longer double support time are associated with high white matter disease and subclinical strokes.

Subclinical brain magnetic resonance imaging abnormalities predict physical functional decline in high-functioning older adults

OBJECTIVES

To determine whether severity of subclinical brain magnetic resonance imaging (MRI) abnormalities predicts incident self-reported physical impairment or rate of decline in motor performance.

DESIGN

Longitudinal analysis, average follow-up time: 4.0 years.

SETTING

Cardiovascular Health Study (CHS).

PARTICIPANTS

CHS participants with modified Mini-Mental State Examination (3MS) score of 80 or greater, no self-reported disability, no history of stroke, and at least one assessment of mobility (n=2,450, mean age=74.4).

MEASUREMENTS

Brain MRI abnormalities (ventricular enlargement, white matter hyperintensities, subcortical and basal ganglia small brain infarcts), self-reported physical impairment (difficulty walking half a mile or with one or more activities of daily living), and motor performance (gait speed, timed chair stand).

RESULTS

After adjusting for demographics, cardiovascular risk factors, and diseases, risk of incident self-reported physical impairment was 35% greater for those with severe ventricular enlargement than for those with minimal ventricular enlargement, 22% greater for those with moderate white matter hyperintensities than for those with minimal white matter hyperintensities, and 26% greater for participants with at least one brain infarct than for those with no infarcts. Those with moderate to severe brain abnormalities experienced faster gait speed decline (0.02 m/s per year) than those with no MRI abnormalities (0.01 m/s per year). Further adjustment for incident stroke, incident dementia, and 3MS score did not substantially attenuate hazard ratios for incident self-reported physical impairment or coefficients for decline in gait speed.

CONCLUSION

Subclinical structural brain abnormalities in high-functioning older adults can increase the risk of developing physical disabilities and declining in motor performance.

Significant correlations of plasma homocysteine and serum methylmalonic acid with movement and cognitive performance in elderly subjects but no improvement from short-term vitamin therapy: a placebo-controlled randomized study

BACKGROUND

Deficiencies of vitamin B-12, folic acid, and vitamin B-6-as defined by laboratory measures-occur in 10-20% of elderly subjects. The clinical significance remains unresolved.

OBJECTIVE

The objective was to explore any association between vitamin status and vitamin treatment and movement and cognitive performance in elderly subjects.

DESIGN

Community-dwelling subjects (n = 209) with a median age of 76 y were randomly assigned to daily oral treatment with 0.5 mg cyanocobalamin, 0.8 mg folic acid, and 3 mg vitamin B-6 or placebo (double blind) for 4 mo. Movement and cognitive performance tests were performed before and after treatment.

RESULTS

A high plasma total homocysteine (tHcy) concentration (> or =16 micromol/L) was found in 64% of men and in 45% of women, and a high serum methylmalonic acid (MMA) concentration (> or =0.34 micromol/L) was found in 11% of both sexes. Movement time, digit symbol, and block design (adjusted for age, sex, smoking, and creatinine) correlated independently with plasma tHcy (P < 0.01, < 0.05, and < 0.01, respectively); the simultaneity index and block design correlated with serum MMA (P < 0.05 for both). Vitamin therapy significantly decreased plasma tHcy (32%) and serum MMA (14%). No improvements were found in the movement or cognitive tests compared with placebo. Neither vitamin therapy nor changes in plasma tHcy, serum MMA, serum vitamin B-12, plasma folate, or whole-blood folate correlated with changes in movement or cognitive performance.

CONCLUSIONS

High plasma tHcy and serum MMA were prevalent and correlated inversely with movement and cognitive performance. Oral B vitamin treatment normalized plasma tHcy and serum MMA concentrations but did not affect movement or cognitive performance. This might have been due to irreversible or vitamin-independent neurocognitive decline or to an insufficient dose or duration of vitamins.

Psychiatric epidemiology of old age: the H70 study--the NAPE lecture 2003

OBJECTIVE

To describe methodological issues and possibilities in the epidemiology of old age psychiatry using data from the H70 study in Göteborg, Sweden.

METHOD

A representative sample born during 1901-02 was examined at 70, 75, 79, 81, 83, 85, 87, 90, 92, 95, 97, 99 and 100 years of age, another during 1906-07 was examined at 70 and 79 years of age, and samples born between 1922 and 1930 were examined at 70 years of age. The study includes psychiatric examinations and key informant interviews performed by psychiatrists, physical examinations performed by geriatricians, psychometric testings, blood sampling, computerized tomographies of the brain, cerebrospinal fluid analyses, anthropometric measurements, and psychosocial background factors.

RESULTS

Mental disorders are found in approximately 30% of the elderly, but is seldom detected or properly treated. Incidence of depression and dementia increases with age. The relationship between blood pressure and Alzheimer's disease is an example of how cross-sectional and longitudinal studies yield completely different results. Brain imaging is an important tool in epidemiologic studies of the elderly to detect silent cerebrovascular disease and other structural brain changes. The high prevalence of psychotic symptoms is an example of the importance to use several sources of information to detect these symptoms. Dementia should be diagnosed in all types of studies in the elderly, as it influences several outcomes such as mortality, blood pressure, and rates of depression. Suicidal feelings are rare in the elderly and are strongly related to mental disorders.

CONCLUSION

Modern epidemiologic studies in population samples should be longitudinal and include assessments of psychosocial risk factors as well as comprehensive sets of biologic markers, such as brain imaging, neurochemical analyses, and genetic information to maximize the contribution that epidemiology can provide to increase our knowledge about the etiology of mental disorders.

A longitudinal study on changes of movement performance and their relation to medical conditions in a female population followed from age 70 to 78

We described longitudinal changes of movement performance in a population-based sample of women followed from age 70 to 78. We also studied the cross-sectional relationships between medical conditions and movement performance at baseline, and longitudinal relationships between baseline medical conditions and changes of movement performance. Two hundred and thirty-four women aged 70 years participated in the baseline study, and 88 women participated in a follow-up study 8 years later. Movement performance was measured by an optoelectronic test, the postural-locomotor-manual (PLM) test, which objectively and precisely measures the subject's mobility of lower and upper extremities. Information on medical conditions including selected diseases and symptoms were obtained by self-report and/or by physical examination. Movement time (MT), an indicator of the overall movement performance of the PLM test, increased over 8 years. This change was mainly related to prolonged duration of the locomotor phase (walking forward), but not to the duration of the manual phase (goal-directed arm reaching). At baseline, poor PLM performance was related to hypertension, orthostatic hypotension, cerebrovascular diseases, chronic bronchitis, depression, arthritis, dizziness, chest pain, dyspnea, joint problems, leg pain, tiredness, number of diseases and number of symptoms at baseline. Increased MT during follow-up was associated with arthritis and dyspnea at baseline, and newly developed diseases during follow-up. Our study results indicated that 70-year-old women had a general slowing of their movement performance over 8 years. Age-related decrements of movement performance were more striking in the lower extremities than in the upper extremities. Arthritis and dyspnea at baseline, and incident diseases during follow-up were related to this age-related decline of movement performance.

Motor performance in relation to age, anthropometric characteristics, and serum lipids in women

BACKGROUND

The relationships between motor performance and age, anthropometric characteristics, and serum lipids were studied in a population-based sample of women (N = 865).

METHODS

Motor performance was measured by a precise laboratory test, the Postural-Locomotion-Manual test, using an optoelectronic technique. Anthropometric measurements included body mass index (BMI) and waist-to-hip ratio. Blood samples were drawn for the measurement of total cholesterol, high-density lipoprotein (HDL) cholesterol, and triglyceride concentrations.

RESULTS

Motor performance deteriorated with age in a curvilinear way. High BMI, high waist-to-hip ratio, high triglycerides and low HDL cholesterol were all correlated to poor motor performance after adjustment for age, vascular disease, hypertension, diabetes, smoking, physical exercise, and some chronic diseases. Stepwise regression analyses showed that age, waist-to-hip ratio, triglycerides, HDL cholesterol, physical exercise, and vascular diseases were independent predictors of motor performance.

CONCLUSIONS

High age, high waist-to-hip ratio, high triglycerides, and low HDL cholesterol were associated with poor motor performance in women. Monitoring abdominal adiposity and serum lipids in clinical work might help us to identify people with early motor impairment and to prevent more severe mobility disability.