Search

Objectives It is well known that low educational attainment is associated with cognitive function decline in older age. Childhood book availability may help to preserve cognitive function in older adults with low education. The study objective was to examine the association between childhood book availability and cognitive function among older adults with low educational attainment, and to investigate the mediating effect of the volume of reading-related brain regions (e.g. superior temporal cortex). Methods A cross-sectional study of community-dwelling older Japanese adults aged 65–84 years was conducted (n  = 474). Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Childhood book availability was assessed using a retrospective questionnaire. Brain region volume was measured using magnetic resonance imaging. Multivariate regression modeling and structural equation modeling were used for analysis. Results Both high educational attainment and childhood book availability were independently associated with high MMSE score. Stratification of educational level showed that childhood book availability was positively associated with MMSE score among participants with low educational attainment (coefficient = 1.48, 95% confidence interval [CI]: 0.31 to 2.66), but not among those with moderate or high educational attainment (coefficient = −0.01, 95% CI: −1.44 to 1.42 and −1.21, 95% CI: −3.85 to 1.42, respectively). Among participants with low educational attainment, left superior temporal cortex volume mediated the association between childhood book availability and MMSE score. Discussion The availability of books in childhood helps to preserve cognitive function in older adults with low education via left superior temporal cortex volume. Further research is needed to replicate these findings. [ABSTRACT FROM AUTHOR]

Background: The noradrenergic systems in the brain maintain cognitive functions including attention/concentration and establishment of long‐term memory. In addition, hypofunction of noradrenergic systems is supposed to be involved in the pathophysiology of Alzheimer's disease. In this study, we tried to examine the possible associations of concentrations of basal salivary 3‐methoxy‐4‐hydroxyphenylglycol (sMHPG), a major metabolite of noradrenaline, and brain volume changes during 4 years in elderly people living in a rural community. Methods: The survey was conducted twice in Kurokawa‐cho, Imari, Saga Prefecture, Japan, among people aged 65 years and older. We collected data from 226 residents. Measurements of sMHPG and brain MRIs were collected at Time 1 (2005–2007). Follow‐up brain MRIs were taken at Time 2 (2009–2011). A total of 70 participants (18 men, mean age 71.9 ± 4.8 years; 52 women, mean age 72.0 ± 4.3 years) completed this survey. Concentrations of sMHPG at baseline were divided into two groups using the mean value (12.83 ng/ml). We compared the brain volumes between groups with higher and lower sMHPG concentrations over time using voxel‐based morphometry implemented with statistical parametric mapping. Results: In participants with higher sMHPG concentrations at baseline, brain volumes including right precuneus were significantly larger 4 years after baseline than those with lower sMHPG concentrations at baseline. No interaction between sMHPG concentration and MRI acquisition interval was found. Conclusion: Our results suggest that higher sMHPG concentrations in elderly people might be associated with maintenance of brain volume, especially in brain regions closely related to cognitive function. [ABSTRACT FROM AUTHOR]

The detrimental effects of high-level mercury exposure on the central nervous system as well as effects of low-level exposure during early development have been established. However, no previous studies have investigated the effects of mercury level on brain morphometry using advance imaging techniques in young adults. Here, utilizing hair analysis which has been advocated as a method for biological monitoring, data of regional gray matter volume (rGMV), regional white matter volume (rWMV), fractional anisotropy (FA) and mean diffusivity (MD), cognitive functions, and depression among 920 healthy young adults in Japan, we showed that greater hair mercury levels were weakly but significantly associated with diminished cognitive performance, particularly on tasks requiring rapid processing (speed measures), lower depressive tendency, lower rGMV in areas of the thalamus and hippocampus, lower rWMV in widespread areas, greater FA in bilaterally distributed white matter areas overlapping with areas of significant rWMV reductions and lower MD of the widely distributed gray and white matter areas particularly in the bilateral frontal lobe and the right basal ganglia. These results suggest that even normal mercury exposure levels in Japan are weakly associated with differences of brain structures and lower neurobehavioral performance and altered mood among young adults. An analysis of cognitive and brain structural data from over 900 Japanese participants reveals a relationship between increased hair mercury levels and reduced cognitive performance and reductions in gray and white matter volume. [ABSTRACT FROM AUTHOR]

The detrimental effects of high-level mercury exposure on the central nervous system as well as effects of low-level exposure during early development have been established. However, no previous studies have investigated the effects of mercury level on brain morphometry using advance imaging techniques in young adults. Here, utilizing hair analysis which has been advocated as a method for biological monitoring, data of regional gray matter volume (rGMV), regional white matter volume (rWMV), fractional anisotropy (FA) and mean diffusivity (MD), cognitive functions, and depression among 920 healthy young adults in Japan, we showed that greater hair mercury levels were weakly but significantly associated with diminished cognitive performance, particularly on tasks requiring rapid processing (speed measures), lower depressive tendency, lower rGMV in areas of the thalamus and hippocampus, lower rWMV in widespread areas, greater FA in bilaterally distributed white matter areas overlapping with areas of significant rWMV reductions and lower MD of the widely distributed gray and white matter areas particularly in the bilateral frontal lobe and the right basal ganglia. These results suggest that even normal mercury exposure levels in Japan are weakly associated with differences of brain structures and lower neurobehavioral performance and altered mood among young adults. An analysis of cognitive and brain structural data from over 900 Japanese participants reveals a relationship between increased hair mercury levels and reduced cognitive performance and reductions in gray and white matter volume. [ABSTRACT FROM AUTHOR]

BACKGROUND: Stroke frequently induces visual problems, which impair activities of daily living, lead to falls, and require rehabilitation. However, visual dysfunction has not been well characterized in stroke. OBJECTIVE: The purpose of this study was to characterize visual function in patients with stroke and the association of these characteristics with neurological dysfunction and lesion hemisphere. METHODS: In 40 patients with stroke and 321 control subjects, we carried out an assessment of a broad panel of visual and neurological functional metrics to identify risk factors for specific visual impairments in stroke. RESULTS: Patients with stroke exhibited a significantly higher rate of occurrence for impairments in all visual metrics assessed, when compared to healthy controls. Risk for particular visual deficits varied according to lesion side (right versus left hemisphere) and specific types of neurological dysfunction. CONCLUSIONS: Detailed assessment of visual function in patients with stroke can help to clarify the risk of various types of visual impairment. Moreover, as visual function assessment in patients with stroke is difficult, knowledge of the correlation of visual impairments with different neurological dysfunctions observed in stroke and lesion side will help predict vision problems and inform optimal corrective measures in treating patients with stroke. [ABSTRACT FROM AUTHOR]

Aim Neuronal degeneration in the locus coeruleus occurs in the early phase of Alzheimer's disease, similar to mild cognitive impairment. The locus coeruleus produces norepinephrine, a deficiency of which causes both memory disturbance and psychological symptoms. Thus, we evaluated signal alterations in the locus coeruleus of patients with Alzheimer's disease and mild cognitive impairment using a high-resolution fast spin-echo T1-weighted imaging. Methods A total of 22 patients with Alzheimer's disease, 47 patients with mild cognitive impairment and 26 healthy controls were prospectively examined by high-resolution fast spin-echo T1-weighted imaging at 3 Tesla. Signal intensities in the locus coeruleus were manually measured and expressed relative to those in the adjacent white matter structures as contrast ratios. Results Locus coeruleus contrast ratios were significantly reduced in patient groups with Alzheimer's disease, mild cognitive impairment that converted to Alzheimer's disease and mild cognitive impairment that did not convert to Alzheimer's disease (1.80-16.09% [median, 9.30%], 3.45-14.84% [median 6.87%] and 3.01-19.19% [median 7.72%], respectively) compared with the healthy control group (6.24-20.94% [median 14.35%]; P < 0.0001). The sensitivity and specificity for discriminating these diseases were 85.0% and 69.2%, respectively, which suggests that this measurement can be carried out reliably. There was no significant difference in the locus coeruleus contrast ratios among the Alzheimer's disease, mild cognitive impairment-converted and mild cognitive impairment-non-converted groups. Conclusions High-resolution fast spin-echo T1-weighted imaging can show signal attenuation in the locus coeruleus of patients with Alzheimer's disease or with mild cognitive impairment whose pathology may or may not eventually convert to Alzheimer's disease. Geriatr Gerontol Int 2015; 15: 334-340. [ABSTRACT FROM AUTHOR]

Objectives. It has been reported that disturbance in sensory and motor function may induce sensorimotor incongruence and produce pain, discomfort and other sensations in healthy volunteers. One study suggested that sensorimotor incongruent information to healthy subjects results in increased neuronal activity in the posterior parietal cortex (PPC) and dorsolateral prefrontal cortex; however, this study did not take into consideration the discomfort induced by sensorimotor incongruence. The present study attempted to characterize intracortical electrical activities for sensorimotor incongruence in the frequency domain. In our study, electroencephalogram (EEG) cortical sources were compared between sensorimotor congruence and sensorimotor incongruence. In addition, high and no discomfort subgroups were compared during sensorimotor incongruence.Methods. Eighteen healthy female subjects participated in this study. Subjects were then asked to flex/extend both arms in a congruent/incongruent manner while viewing a whiteboard/mirror. EEG was performed to determine the cortical activation during sensorimotor congruence and incongruence.Results. Alpha band activity in the right posterior parietal cortex during sensorimotor incongruence was significantly lower than that of sensorimotor congruence. The source activities induced in the anterior cingulate cortex (ACC) beta band activity and the posterior cingulate cortex (PCC) alpha band activity significantly decreased in the high-discomfort vs the no-discomfort subgroup.Conclusion. The present findings suggest that the ACC and PCC are more activated in the high-discomfort subgroup than in the no-discomfort subgroup during sensorimotor incongruence. This method may evaluate the effectiveness of new medication therapy and/or rehabilitation by assessing the difference in the neuronal activity of chronic patients before and after treatment. [ABSTRACT FROM PUBLISHER]

Background. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is one of the standard surgical treatments for advanced Parkinson's disease. However, it has been difficult to accurately localize the stimulated contact area of the electrode in the subthalamic nucleus and its adjacent structures using a two-dimensional atlas. The goal of this study is to verify the real and detailed localization of stimulated contact of the DBS electrode therapeutically inserted into the STN and its adjacent structures using a novel computed three-dimensional atlas built by a personal computer. Method. A three-dimensional atlas of the STN and its adjacent structures (3D-Subthalamus atlas) was elaborated on the basis of sagittal slices from the Schaltenbrand and Wahren stereotactic atlas on a personal computer utilizing a commercial software. The electrode inserted into the STN and its adjacent structures was superimposed on our 3D-Subthalamus atlas based on intraoperative third ventriculography in 11 cases. Findings. Accurate localization of the DBS electrode was identified using the 3D-Subthalamus atlas, and its clinical efficacy of the electrode stimulation was investigated in all 11 cases. Conclusion. This study demonstrates that the 3D-Subthalamus atlas is a useful tool for understanding the morphology of deep brain structures and for the precise anatomical position findings of the stimulated contact of a DBS electrode. The clinical analysis using the 3D atlas supports the contention that the stimulation of structures adjacent to the STN, particularly the zona incerta or the field of Forel H, is as effective as the stimulation of the STN itself for the treatment of advanced Parkinson's disease. [ABSTRACT FROM AUTHOR]

Introduction: Whether the degree of white matter hyperintensities (WMHs) shows a significant correlation with the rate of global gray matter volume decline over a period following initial baseline measurement remains unclear. The purpose of the present study was to reveal the relationship between the degree of WMHs at baseline and the rate of global gray matter volume decline by applying a longitudinal design. Methods: Using a 6-year longitudinal design and magnetic resonance images of the brains of 160 healthy individuals aged over 50 years and living in the community, we analyzed the correlation between degree of WMHs using Fazekas scaling at baseline and rate of global gray matter volume decline 6 years later. To obtain the rate of global gray matter volume decline, we calculated global gray matter volume and intracranial volume at baseline and at follow-up using a fully automated method. Results: The annual percentage change in the gray matter ratio (GMR, APC), in which GMR represents the percentage of gray matter volume in the intracranial volume, showed a significant positive correlation with the degree of deep WMHs and periventricular WMHs at baseline, after adjusting for age, gender, present history of hypertension, and diabetes mellitus. Conclusion: Our results suggest that degree of WMHs at baseline predicts the rate of gray matter volume decline 6 years later and that simple visual scaling of WMHs could contribute to predicting the rate of global gray matter volume decline. [ABSTRACT FROM AUTHOR]

Introduction: The effects of aging on brain volume are generally investigated using voxel-based morphometry (VBM) or the manually traced region-of-interest (ROI) method. We introduce an atlas-based method as a methodological alternative that calculates absolute volume as a non-biased and semi-automatic whole-brain technique. Methods: We enrolled 115 healthy females (mean age, 36.7 years) and 130 healthy males (mean age, 37.1 years). Volume data were acquired using a 1.5 tesla magnetic resonance scanner. After spatial normalization, a lobar-based atlas template was applied, and the absolute volumes of the frontal, temporal, parietal, and occipital lobes and the sublobar and limbic areas were calculated bilaterally. The effects of age on regional brain volume were evaluated statistically. Results: The volume of all ROIs declined linearly with increasing age. The bilateral frontal lobes showed the steepest involution. Analysis of variance revealed significant laterality and interaction of gender and age. Conclusion: The atlas-based method introduced in the present study has advantages over the manually traced ROI method in its objectivity, coverage, and time requirement and has an advantage over the VBM method in its computability of absolute volume. The results are largely in agreement with those reported previously, thereby reconfirming the importance of matching gender and age in analyzing brain disorders. [ABSTRACT FROM AUTHOR]

The relationship between physical frailty and regional gray matter volume in the brain was investigated among community-dwelling older Japanese people. Participants (N = 835; age range 65–89 years) were community-dwelling older adults in Obu City and Higashiura Town in Aichi Prefecture, Japan. Physical frailty was determined by the modified criteria of the Cardiovascular Health Study, which included weight loss, slowness, weakness, exhaustion, and low physical activity. Regional gray matter volumes were evaluated from 3-dimensional T1-weighted magnetic resonance images by statistical parametric mapping. The relationship between physical frailty and regional gray matter volume was analyzed with an analysis of covariance design using statistical parametric mapping adjusting for age, sex, and education level. The voxel-based analyses showed that physical frailty per se was not significantly associated with any brain region. However, weakness was associated with reduced gray matter volumes in the hippocampus, amygdala, and fusiform gyrus, and slowness was associated with reduced gray matter volumes in the hippocampus, amygdala, fusiform gyrus, medial prefrontal and orbitofrontal cortex, inferior frontal gyrus, primary somatosensory cortex, insula, superior temporal sulcus, and cerebellum. Other components of physical frailty were not associated with the gray matter volumes in any regions. The weakness and slowness components of physical frailty were linked to reduced gray matter volume in brain regions associated with not only physical mobility but also cognitive functions and social processes. This study addressed the underlying mechanisms in the progression of physical, cognitive, and social frailty, from the perspective of brain structures that are associated with frailty. [ABSTRACT FROM AUTHOR]