Leukoaraiosis, a common ischaemic lesion diagnosed using magnetic resonance imaging (MRI), can influence driving safety performance (DSP). Most older drivers with leukoaraiosis are unaware of their ...affliction. Japan is a super-aged country, where preventing accidents caused by older drivers is an urgent national issue. We investigated the subcortical and periventricular leukoaraiosis regions that were most involved in DSP decline. The driving skills of 101 drivers (49 men, 52 women; mean age, 77.88 ± 3.77 years) without dementia were assessed by official driving instructors, using actual vehicles on a closed-circuit course. Parietal and occipital (but not frontal or temporal) leukoaraiosis volumes were significantly correlated with decreased DSP scores regardless of age, especially when turning right at intersections, which needs more attention than turning left because left-side driving is legally enforced in Japan. Occipital leukoaraiosis was also involved via a decline in dynamic visual cognitive function. MRI-based assessment of leukoaraiosis volume and localisation may enable the identification of older drivers prone to DSP deterioration. Risk factors for leukoaraiosis include smoking and lifestyle-related diseases such as hypertension. Thus, brain healthcare in patients with MRI-diagnosed leukoaraiosis may be particularly useful for the risk management of traffic accidents caused by the elderly in Japan.
This large-scale study including 2548 healthy adults with no clinical attention-deficit/hyperactivity disorder (ADHD) diagnosis intended to clarify the complex relationships between cerebral grey ...matter volumes (GMVs), ADHD traits, and driving safety behaviours. Path analysis of magnetic resonance imaging (MRI) results and questionnaires about ADHD traits and traffic crashes over the past decade revealed significant correlations of ADHD traits with different brain regions relevant to different cognitive functions. The left precuneus responsible for visuospatial cognition was the sole region correlated with all ADHD trait categories, suggesting it plays an important role in understanding driving safety and traffic crashes. For the first time, a strong relationship was found among regional GMVs, ADHD traits, and real-life traffic crashes. These insights into the complex interplay may inform the development of an effective intervention with MRI examination to prevent traffic crashes. Large-scale brain volumetric data may further open social applications of behaviour science and neuroimaging.
Abstract Purpose The purpose of this study was to investigate whether the signal intensity of the substantia nigra pars compacta (SNc) and locus coeruleus (LC) on neuromelanin-sensitive magnetic ...resonance imaging (MRI) can discriminate early-stage parkinsonism disorders, for which differential diagnosis is generally difficult. Methods Neuromelanin-sensitive MRI at 3 T was performed in 53 patients with early parkinsonism and 22 healthy controls. After an observation period of >1.5 year, the patients were clinically diagnosed with Parkinson's disease (PD; n = 30), multiple system atrophy with predominant parkinsonism (MSA-P; n = 10), or progressive supranuclear palsy syndrome (PSPS; n = 13). The signal intensity of the lateral, central, and medial parts of the SNc and the LC were measured and the contrast ratios (CR) against adjacent white-matter structures was calculated. Results The CR of the lateral SNc was lower in the PD and MSA-P groups than in the PSPS and control groups ( p = 0.0001–0.05). The CR of the LC was lower in the PD group than in the other groups ( p = 0.0001–0.05). Sensitivity and specificity of the CRs for discriminating PD from MSA-P was 60% and 90%, respectively, those for PD/PSPS were 63–88% and 77–92%, respectively, and those for MSA-P/PSPS were 80% and 85%, respectively. These properties were comparable or better to MIBG scintigraphy. Conclusions Neuromelanin-sensitive MRI can depict differences in signal intensity of the lateral SNc and the LC among the parkinsonism disorders at their early stages.
This study investigated the relationship between cerebral gray matter (GM) regions and driving safety behaviors (DSBs) of 98 older drivers without dementia (mean age, 77.72 ± 3.677 years). Their DSBs ...were evaluated on actual vehicles running on a closed-circuit course. The DSB was scored in six categories: DSB1, visual search behavior; DSB2, speeding; DSB3, signaling of the indicator; DSB4, vehicle stability; DSB5, positioning; and DSB6, steering. The scores were calculated by a single driving instructor; larger scores indicated safer driving performances. Regional GM volumes were measured with voxel-based morphometry by magnetic resonance imaging (MRI). Out of 56 GM regions, 18 were correlated with DSB categories except for DSB4. When a single GM region was correlated with multiple DSB categories, a positive or negative response was uniformly determined for the respective region despite clear differences in the DSB categories. This result suggests the possible existence of two contradictory mechanisms in the brain for DSB. The left postcentral gyrus may largely function in regulating DSBs because it was negatively correlated with five of six DSB categories. Thus, MRI's measurement of regional GM volumes may help deepen the understanding of the diversity and complexity inherent in brain functions for DSBs.
•Healthy volunteer subjects (N = 583) underwent a diffusion tensor imaging scan.•The fractional anisotropy of the superior longitudinal fasciculus was evaluated.•The Perceptual Organization Index was ...correlated the fractional anisotropy.•The Working Memory Index was correlated the fractional anisotropy.•Results contribute to neuromodulation in the treatment of neurological disorders.
The superior longitudinal fasciculus (SLF) is a white matter structure that has long bidirectional projections among the prefrontal, temporal, occipital, and parietal cortices and extends over a wide area in a human brain. Recently, anatomical details of the SLF have been clarified using a diffusion tensor imaging (DTI) template of subjects from the Human Connectome Project. However, the neurobehavioral functions of the SLF have not been fully elucidated. It is speculated that the SLF contributes to a broad cognitive domain including visuospatial nonverbal cognitive ability and verbal memory ability because of its anatomical location; however, previous findings in imaging studies are inconsistent. Showing the contribution of the SLF to cognitive function may be important for improving our understanding of the functional role of white matter structures in the human brain. This study aimed to identify the relationship between DTI indices of the SLF and the Verbal Comprehension, Perceptual Organization, Working Memory and Processing Speed Indices of the Wechsler Adult Intelligence Scale-Third Edition using regression analysis, accounting for the effects of age, sex and scanner type in 583 healthy volunteers. We showed significant correlations between the fractional anisotropy of the left SLF and the Perceptual Organization Index (β = 0.21, p = 4.5×10–4) and Working Memory Index (β = 0.19, p = 4.0×10–4). These findings may have implications for the rehabilitation of cognitive function in patients with neurological disorders.
To examine the association between diabetes and gray matter atrophy patterns in a general older Japanese population.
In 2012, a total of 1,189 community-dwelling Japanese aged ≥65 years underwent ...brain MRI scans. Regional gray matter volumes (GMV) and intracranial volume (ICV) were measured by applying voxel-based morphometry (VBM) methods. The associations of diabetes and related parameters with the regional GMV/ICV were examined using an ANCOVA. The regional gray matter atrophy patterns in the subjects with diabetes or elevated fasting plasma glucose (FPG) or 2-h postload glucose (2hPG) levels were investigated using VBM.
Subjects with diabetes had significantly lower mean values of GMV/ICV in the frontal lobe, temporal lobe, insula, deep gray matter structures, and cerebellum than subjects without diabetes after adjusting for potential confounders. A longer duration of diabetes was also significantly associated with lower mean values of GMV/ICV in these brain regions. The multivariable-adjusted mean values of the temporal, insular, and deep GMV/ICV decreased significantly with elevating 2hPG levels, whereas higher FPG levels were not significantly associated with GMV/ICV of any brain regions. In the VBM analysis, diabetes was associated with gray matter atrophy in the bilateral superior temporal gyri, right middle temporal gyrus, left inferior temporal gyrus, right middle frontal gyrus, bilateral thalami, right caudate, and right cerebellum.
The current study suggests that a longer duration of diabetes and elevated 2hPG levels are significant risk factors for gray matter atrophy in various brain regions.
To investigate the association between diabetes and brain or hippocampal atrophy in an elderly population.
A total of 1,238 community-dwelling Japanese subjects aged ≥65 years underwent brain MRI ...scans and a comprehensive health examination in 2012. Total brain volume (TBV), intracranial volume (ICV), and hippocampal volume (HV) were measured using MRI scans for each subject. We examined the associations between diabetes-related parameters and the ratios of TBV to ICV (an indicator of global brain atrophy), HV to ICV (an indicator of hippocampal atrophy), and HV to TBV (an indicator of hippocampal atrophy beyond global brain atrophy) after adjustment for other potential confounders.
The multivariable-adjusted mean values of the TBV-to-ICV, HV-to-ICV, and HV-to-TBV ratios were significantly lower in the subjects with diabetes compared with those without diabetes (77.6% vs. 78.2% for the TBV-to-ICV ratio, 0.513% vs. 0.529% for the HV-to-ICV ratio, and 0.660% vs. 0.676% for the HV-to-TBV ratio; all P < 0.01). These three ratios decreased significantly with elevated 2-h postload glucose (PG) levels (all P for trend <0.05) but not fasting plasma glucose levels. Longer duration of diabetes was significantly associated with lower TBV-to-ICV, HV-to-ICV, and HV-to-TBV ratios. The subjects with diabetes diagnosed in midlife had significantly lower HV-to-ICV and HV-to-TBV ratios than those without and those diagnosed in late life.
Our data suggest that a longer duration of diabetes and elevated 2-h PG levels, a marker of postprandial hyperglycemia, are risk factors for brain atrophy, particularly hippocampal atrophy.
Subcortical regions have a pivotal role in cognitive, affective, and social functions in humans, and the structural and functional abnormalities of the regions have been associated with various ...psychiatric disorders. Although previous studies focused on the neurocognitive and socio-functional consequences of prefrontal and tempolo-limbic abnormalities in psychiatric disorders, those of subcortical structures remain largely unknown. Recently, MRI volume alterations in subcortical structures in patients with schizophrenia have been replicated in large-scale meta-analytic studies. Here we investigated the relationship between volumes of subcortical structures and neurocognitive and socio-functional indices in a large sample of patients with schizophrenia. First, we replicated the results of meta-analyses: the regional volumes of the bilateral hippocampus, amygdala, thalamus and nucleus accumbens were significantly smaller for patients (N = 163) than for healthy controls (HCs, N = 620). Second, in the patient group, the right nucleus accumbens volume was significantly correlated with the Digit Symbol Coding score, which is known as a distinctively characteristic index of cognitive deficits in schizophrenia. Furthermore, the right thalamic volume was significantly correlated with social function scores. In HCs, no significant correlation was found. The results from this large-scale investigation shed light upon the role of specific subcortical nuclei on cognitive and social functioning in schizophrenia.
Patients with schizophrenia show severe impairment in social function and have difficulty in their daily social life. Although a recent large-scale multicenter study revealed alterations in white ...matter microstructures, the association between these anatomical changes and social dysfunction in schizophrenia remains unknown. Therefore, we investigated the association between the white matter integrity of regions of interest and social function in schizophrenia. A total of 149 patients with schizophrenia and 602 healthy comparison subjects (HCS) underwent DTI and completed the Picture Arrangement subtest of the Wechsler Adult Intelligence Scale-Third Edition and the Finance subscale of the University of California, San Diego, Performance-Based Skills Assessment Brief, as social indices of interest. The fractional anisotropy (FA) in the anterior corona radiata and corpus callosum was significantly lower in patients than in HCS, and the radial diffusivity (RD) in the anterior corona radiata and corpus callosum was significantly higher in patients. The Picture Arrangement and Finance scores were both significantly impaired in patients. The effect of the FA of the right anterior corona radiata on the Finance score and the Picture Arrangement score, of the RD of the right anterior corona radiata on the Picture Arrangement score, and of the RD of the corpus callosum on the Picture Arrangement score were significant. In conclusion, our results confirmed the association between structural connectivity in the right frontal white matter and corpus callosum and social function in schizophrenia. These findings may provide a foundation for developing an intervention for functional recovery in schizophrenia.
Chronic fatigue syndrome (CFS), a clinical entity of chronic fatigue, has been associated with a decrease in regional gray matter volume (rGMV). In this study targeting a large number of healthy ...middle-aged individuals without CFS, the relationship between fatigue perception and rGMV was investigated. Considering that the work setting is an environmental factor that influences fatigue perception among healthy individuals, the differences between desk workers and non-desk workers were investigated. Chalder Fatigue Questionnaire (CFQ) scores were used for perceptional evaluation of fatigue, and rGMV of 110 brain regions was adapted with Statistical Parametric Mapping (SPM) 8 on 1.5 T magnetic resonance imaging (MRI) results for the volumetric calculation of gray matter. The CFQ scores were negatively correlated with the right supplementary motor area (SMC) and positively correlated with the right superior parietal lobule (SPL) and left basal forebrain in all participants (
n
= 1,618). In desk workers and non-desk workers, the CFQ scores correlated with different regions and yielded different mechanisms of fatigue perception in the brain. Identifying the gray matter regions correlated with fatigue perception in healthy individuals may help understand the early stage of fatigue progression and establish future preventive measures.
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