Gait performance in older adults across the cognitive spectrum: Results from the GAIT cohort.

BACKGROUND: Gait performance can provide valuable insights into cognitive functioning in older adult and may be used to screen for cognitive impairment. However, the optimal test condition and spatiotemporal parameter for accuracy have not yet been determined. This study aims to determine the gait measure with the highest accuracy identifying cognitive decline. METHODS: A total of 711 participants were recruited, including 332 cognitively healthy individuals, 264 with mild cognitive impairment (MCI), and 115 with dementia, with a mean age of 72 years (interquartile range 69-76), and 43% (n = 307) of women. The participants underwent gait assessment in three different conditions, including a single task and dual tasks of counting backward by ones and naming animals. RESULTS: Gait performance was deteriorated as cognitive impairment progressed. The gait test performed during naming animals condition was the most accurate in differentiating between cognitive groups. Specifically, the naming animals gait speed was more accurate in discriminating control participants from those with cognitive impairment (area under the curve [AUC] = 76.9% for MCI and 99.7% for people with dementia with control group as reference). The coefficient of stride length variability while naming animals was the most effective parameter in discriminating between MCI and dementia groups (AUC = 96.7%). CONCLUSIONS: The naming animals dual-task gait test can be a valuable assessment for screening cognitive impairment in older adults, regardless of their cognitive abilities. The test is useful in clinical settings for subjects with a range of cognitive profiles.

Associations between gait speed and brain structure in amnestic mild cognitive impairment: a quantitative neuroimaging study.

BACKGROUND: Patients with amnestic mild cognitive impairment (aMCI) present gait disturbances including slower speed and higher variability when compared to cognitively healthy individuals (CHI). Brain neuroimaging could explore higher levels of motor control. Our purpose was to look for an association between morphometrics and gait parameters in each group. We hypothesized that the relation between morphological cerebral alteration and gait speed are different following the group. METHODS: Fifty-three participants (30 with aMCI and 23 CHI) were recruited in this French cross-sectional study (mean 72 ± 5 years, 38% female). Gait speed and gait variability (coefficients of variation of stride time (STV) and stride length (SLV)) were measured using GAITrite® system. CAT12 software was used to analyse volume and surface morphometry like gray matter volume (GMV) and cortical thickness (CT). Age, gender and education level were used as potential cofounders. RESULTS: aMCI had slower gait speed and higher STV when compared to CHI. In aMCI the full adjusted linear regression model showed that lower gait speed was associated with decreased GMV and lower CT in bilateral superior temporal gyri (p < 0.36). In CHI, no association was found between gait speed and brain structure. Higher SLV was correlated with reduced GMV in spread regions (p < 0.05) and thinner cortex in the middle right frontal gyrus (p = 0.001) in aMCI. In CHI, higher SLV was associated with reduced GMV in 1 cluster: the left lingual (p = 0.041). CONCLUSIONS: These findings indicate that lower gait speed is associated with specific brain structural changes as reduced GMV and CT during aMCI.

Volumetric Brain Changes in Older Fallers: A Voxel-Based Morphometric Study.

BACKGROUND: Falls are frequent and severe in older adults, especially among those with cognitive impairments due to altered motor control. Which brain areas are affected among fallers remains yet not elucidated. The objective of this cross-sectional analysis was to determine whether the history of falls correlated with focal brain volume reductions in older adults. METHODS: Participants from the MERE study (n = 208; mean, 71.9 ± 5.9 years; 43% female; 38% cognitively healthy, 41% with mild cognitive impairment and 21% with dementia) were asked about their history of falls over the preceding year and received a 1.5-Tesla MRI scan of the brain. Cortical gray and white matter subvolumes were automatically segmented using Statistical Parametric Mapping. Age, gender, use of psychoactive drugs, cognitive status, and total intracranial volume were used as covariates. RESULTS: Fifty-eight participants (28%) reported history of falls. Fallers were older (P = 0.001), used more often psychoactive drugs (P = 0.008) and had more often dementia (P = 0.004) compared to non-fallers. After adjustment, we found correlations between the history of falls and brain subvolumes; fallers exhibiting larger gray matter subvolumes in striatum, principally in bilateral caudate nucleus, than non-fallers. By stratifying on cognitive status, these neuroanatomical correlates were retrieved only in participants with MCI or dementia. There were no correlations with the subvolumes of white matter. CONCLUSION: Older fallers had larger subvolumes in bilateral striatum than non-fallers, principally within the caudate nucleus. This suggests a possible brain adaptative mechanism of falls in people with neurocognitive decline.

Vitamin D concentration and focal brain atrophy in older adults: a voxel-based morphometric study.

Vitamin D is involved in brain health and function. Our objective was to determine whether lower 25-hydroxyvitamin D (25OHD) concentration was associated with focal brain volume reduction in older adults. Serum 25OHD concentration was measured among 53 older adults (72 ± 5 years; 38% female; mean 25OHD = 67.3 ± 20.8 nmol/L). Gray matter volume (GMV) was automatically segmented using voxel-based morphometry with CAT12 software. Covariables were age, gender, education, total intracranial volume, and season. Serum 25OHD was positively associated with GMV in left calcarine sulcus (P < 0.05, TFCE, FWE-corrected). We found atrophy of the calcarine sulcus with lower 25OHD concentrations in older adults.

(Re)organisation of the somatosensory system after early brain lesion: A lateralization index fMRI study.

OBJECTIVE: To evaluate the relationship between neural (re)organization of the somatosensory cortex and impairment of sensory function (2-point discrimination [2PD]) in individuals with unilateral cerebral palsy. METHODS: We included 21 individuals with unilateral cerebral palsy. 2PD thresholds were evaluated on thumb pads, and activation of the somatosensory cortex was recorded by functional MRI (fMRI) during passive movements of the affected hand. A lateralization index (LI) was calculated for the primary sensory (S1) and secondary sensory (S2) cortices and the correlation between the LI and 2PD thresholds was analysed. RESULTS: We found a significant negative correlation between the 2PD thresholds and the S2 LI (r=-0.5, one-tailed P-value=0.01) and a trend towards a negative correlation with the S1 LI (r=-0.4, one-tailed P-value=0.05). CONCLUSION: High levels of activation in the contralesional hemisphere were associated with high levels of sensory impairment in individuals with unilateral cerebral palsy. The interhemispheric (re)organization of the somatosensory system may not effectively compensate for somatosensory impairment.

A Cross-Sectional Study of Treatments for Behavioral Disorders Following Traumatic Brain Injury: Comparison With French Recommendations.

OBJECTIVE: To give a cross-sectional overview of ongoing management of behavioral disorders following traumatic brain injury (TBI) in a region of France, to compare this with recent recommendations from the French Society of Physical Medicine and Rehabilitation (SOFMER), and to evaluate associations between treatments and participant characteristics. SETTING: Outpatients referred to medical or community-based facilities in a region of France. PARTICIPANTS: One hundred twenty-nine adults with moderate to severe TBI, in the postacute period (over 3 months postinjury). DESIGN: Cross-sectional cohort study. MAIN MEASURES: Sociodemographic data, ongoing interventions including psychotherapy and medication, behavioral disorders assessed by the Behavioral Dysexecutive Syndrome Inventory (BDSI). RESULTS: Thirty-three percent of participants received ongoing psychotherapy and 43% were on medication. The most prescribed medications were antidepressants (21%), neuroleptics (18%), anxiolytics (16%), and mood stabilizers (14%). Eighty-five participants (71%) presented a current Behavioral Dysexecutive Syndrome (BDS) according to the BDSI. These participants more frequently received treatment (P = .004), psychotherapy (P = .048), medications (often 2 or more) (P = .007), and particularly antiepileptic mood stabilizers (P = .037) compared with those without BDS. CONCLUSION: Although recommended as first-line treatment, few participants with BDS received psychotherapy. Medications were overused, especially neuroleptics in view of their potential adverse effects. In contrast, recommended medications, such as mood stabilizers and ß-blockers, did not appear to be highly prescribed whatever the evolution. Compliance with recommendations seemed insufficient.