Wechsler Adult Intelligence Scale-IV Research Articles

Influence of regional white matter hyperintensity volume and apolipoprotein E ε4 status on hippocampal volume in healthy older adults.

While total white matter hyperintensity (WMH) volume on magnetic resonance imaging (MRI) has been associated with hippocampal atrophy, less is known about how the regional distribution of WMH volume may differentially affect the hippocampus in healthy aging. Additionally, apolipoprotein E (APOE) ε4 carriers may be at an increased risk for greater WMH volumes and hippocampal atrophy in aging. The present study sought to investigate whether regional WMH volume mediates the relationship between age and hippocampal volume and if this association is moderated by APOE ε4 status in a group of 190 cognitively healthy adults (APOE ε4 status [carrier/non-carrier] = 59/131), ages 50-89. Analyses revealed that temporal lobe WMH volume significantly mediated the relationship between age and average bilateral hippocampal volume, and this effect was moderated by APOE ε4 status (-0.020 (SE = 0.009), 95% CI, [-0.039, -0.003]). APOE ε4 carriers, but not non-carriers, showed negative indirect effects of age on hippocampal volume through temporal lobe WMH volume (APOE ε4 carriers: -0.016 (SE = 0.007), 95% CI, [-0.030, -0.003]; APOE ε4 non-carriers: .005 (SE = 0.006), 95% CI, [-0.006, 0.017]). These findings remained significant after additionally adjusting for sex, years of education, hypertension status and duration, cholesterol status, diabetes status, Body Mass Index, history of smoking, and the Wechsler Adult Intelligence Scale-IV Full Scale IQ. There were no significant moderated mediation effects for frontal, parietal, and occipital lobe WMH volumes, with or without covariates. Our findings indicate that in cognitively healthy older adults, elevated WMH volume regionally localized to the temporal lobes in APOE ε4 carriers is associated with reduced hippocampal volume, suggesting greater vulnerability to brain aging and the risk for Alzheimer's disease.

Functional neural correlates of the WAIS‐IV Block Design Test in older adult with mild cognitive impairment and Alzheimer’s disease dementia

AbstractBackgroundWhile the Wechsler Adult Intelligence Scale IV (WAIS‐IV) Block Design Test (BDT) has is widely used in both research and clinical setting as a measure of cognitive decline in the aging population, its functional neural substrates has not been clearly identified. Hence, the aim of the current study is to identify the functional neural correlates of the BDT in older adults with mild cognitive impairment (MCI) and Alzheimer’s disease (AD) dementia patients.MethodThe current study includes 213 cognitively impaired (135 MCI and 78 AD dementia) middle and old‐aged adults. All participants underwent comprehensive clinical and neuropsychological assessments and 18F‐fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) scans. The BDT performance was assessed using the Wechsler Adult intelligence scale‐IV Korean version. Voxel‐wise analyses were used to investigate the correlation between regional cerebral glucose metabolism and BDT performance. The same analyses were conducted on the subgroups categorized by clinical severity based on the Clinical Dementia Rating.ResultThe participants had a mean age of 73.1 (SD = 7.4) years, mean years of education of 9.8 (SD = 4.9), mean BDT score of 20.9 (SD = 9.1), and 67.1% were female. Significant positive correlations between the BDT performance and regional cerebral glucose metabolism were found bilaterally in the inferior parietal lobule and thalamus, the right superior temporal gyrus and left occipital precuneus.ConclusionThe findings indicated that BDT performance in MCI and AD dementia patients functionally relies on the brain regions known to be associated with motor and executive functions as well as visuospatial functions.

Encoding of facial expressions in individuals with adult-onset myotonic dystrophy type 1

ABSTRACT Introduction: Emotional issues are often reported among individuals with myotonic dystrophy type 1 (DM1) and some studies have suggested that deficits in ability to quickly encode emotions may contribute to these problems. However, poor performance on emotion encoding tasks could also be explained by a more general cognitive deficit (Full Scale IQ [FSIQ]), rather than a specific deficit in emotional processing. Since individuals with DM1 are known to exhibit difficulties in general cognitive abilities, it is important to account for FSIQ when evaluating emotion encoding. The aim of this study was to compare emotion encoding abilities between individuals with and without DM1, while adjusting for the impact of general cognitive abilities (FSIQ). Methods: The sample included 35 individuals with adult-onset DM1 and 54 unaffected adults who completed assessments of emotion encoding abilities (Ekman faces test) and general cognitive abilities (Wechsler Adult Intelligence Scale-IV). Performance on the emotion encoding task was operationalized as proportion correct and response time. Group differences in proportion correct were evaluated with generalized linear regression, while linear regression models were used to determine the effect of group on response time. Models were adjusted for age, sex, and FSIQ. The false discovery rate (FDR) was applied to control false positives due to multiple comparisons (pfdr ). Results: No significant group differences were observed for emotion encoding abilities (all pfdr > 0.13). FSIQ was significantly associated with proportion correct and with response time (all pfdr < 0.05). Conclusions: Emotion encoding appears intact in individuals with DM1 and variation in the ability to encode facial expressions was associated with FSIQ. Further research is required to address the relationship between general cognitive abilities and emotion encoding abilities among DM1 patients.

Cognitive and balance impairments in people with incidental white matter hyperintensities

BackgroundWhite matter hyperintensities (WMHs) is the most frequent type of cerebral small vessel diseases and a common incidental finding in MRI films of the geriatric population. The objectives of this work were to study the existence of occult cognitive and balance impairments in subjects with accidentally discovered WMHs.MethodsThe study was conducted on 44 subjects with accidentally discovered WMHs and 24 non-WMHs subjects submitted to the advanced activity of daily living scale (AADLs), a neurocognitive battery assessing different cognitive domains, Berg balance test (BBT), computerized dynamic posturography (CDP), and brain MRI diffusion tensor tractography (DTT).ResultsWMHs subjects showed a significant decrease in AADLs as well as visual and vestibular ratios of CDP. Regarding the neurocognitive battery, there were significant decreases in MoCA as well as arithmetic test and block design of Wechsler adult intelligence scale-IV in WMHs compared to non-WMHs subjects’ groups (p value < 0.001). Concerning Wisconsin Card Sorting subtests, each preservative response, preservative errors, non-preservative errors and trials to complete the 1st category showed a highly significant increase in WMHs compared to non-WMHs subjects (p values < 0.001). DTT showed a substantial reduction in fractional anisotropy (FA) of each corticospinal tract, thalamocortical connectivity, and arcuate fasciculi.ConclusionSubjects with WMHs have lower cognitive performance and subtle balance impairment which greatly impair their ADLs.

Cognitive impairment and psychopathology in out-of-hospital cardiac arrest survivors in Denmark: The REVIVAL cohort study protocol

IntroductionCognitive impairment and psychopathology caused by brain hypoxia and the traumatic impact of critical illness are common in cardiac arrest survivors and can lead to negative consequences of everyday life...

A-112 Validity of In-Person Assessment of Traumatic Brain Injury Inpatients Using the Brief Test of Adult Cognition by Telephone

Abstract Objective Examine the correlation of the Brief Test of Adult Cognition by Telephone (BTACT) with established neuropsychological tests in an inpatient traumatic brain injury (TBI) population. Method Participants were 55 patients aged 18–76 years (M age = 37 years; 69% male) receiving inpatient rehabilitation for new-onset TBI at a level I trauma center, acute inpatient rehabilitation hospital. The BTACT is a brief cognitive test battery consisting of the following subtests: Word List Immediate and Delayed Recall (episodic verbal memory), Digits Backward (working memory), Number Series (inductive reasoning), Animal Fluency (verbal fluency), and Backward Counting (processing speed). With the intention of mirroring cognitive functions measured by the BTACT, the neuropsychological battery was comprised of the California Verbal Learning Test-2 (CVLT-2), Wechsler Adult Intelligence Scale-IV (WAIS-IV) Digit Span, Trail Making Test (TMT), semantic fluency, phonemic fluency, Symbol Digit Modalities Test, and Wisconsin Card Sorting Test. Results The BTACT was related to established neuropsychological tests across composite scores of overall cognition (r = .64, p &amp;lt; .001), episodic verbal memory (r = .66, p &amp;lt; .001), and executive function (r = .56, p &amp;lt; .001). For BTACT subtests, Word List Immediate Recall and Word List Delayed Recall were correlated with CVLT-2 learning trials total (r = .57, p &amp;lt; .01) and long delay free recall (r = .60, p &amp;lt; .001), respectively. BTACT Digits Backward correlated with WAIS-IV Digit Span (r = .51, p &amp;lt; .01). BTACT Animal Fluency was related to semantic fluency (r = .65, p &amp;lt; .01), phonemic fluency (r = .60, p &amp;lt; .01), and TMT-B (r = .39, p &amp;lt; .01). Conclusion BTACT composite scores of overall cognition, verbal memory, and executive function are valid measures in a TBI inpatient population.

A-213 Comparing WAIS-IV Reliable Digit Span and Age Corrected Scaled Score’s Performance Validity Cutoffs when Patients’ Effort is Determined by One or More Performance Validity Tests (PVTs)

Abstract Objective The purpose of the present study was to compare Wechsler Adult Intelligence Scale-IV (WAIS-IV) Reliable Digit Span (RDS) and Digit Span Age-Corrected Scaled Score (DS-ACSS) sensitivity and specificity, when the effort criterion was determined by between one and five performance validity test (PVT) cut scores. Method Data were collected from 82 adults (18–49) referred for clinical questions of multiple sclerosis, mild traumatic brain injury, and attention deficit hyperactivity disorder. Patients were administered full neuropsychological batteries,with different combinations of PVTs (including Advanced Clinical Solutions Word Choice, Animals raw score, Trails A T-score, Wisconsin Card Sorting Test [WCST; Suhr &amp; Boyer] equation, and California Verbal Learning Test-II Forced Choice). Chi-square and receiver operating characteristic (ROC) analyses were utilized. Results Using established RDS (≤7) and DS-ACSS (≤6) cut scores, specificity was highest (90&amp;37; and 86%, respectively), with equivalent sensitivity (90%), when effort was determined by WCST (Suhr &amp; Boyer) equation failure alone. Related area under the curve for RDS was .90 (CI = .76–1.0) and for DS-ACSS was .88 (CI = .74–1.0). Conclusions In this clinical sample, the highest sensitivity and specificity were observed when the RDS cut score was utilized, and effort was based on the WCST criterion. However, the DS-ACSS cut score resulted in strong sensitivity/specificity combinations across more effort classification groups.

Long-term efficacy and cognitive effects of bilateral hippocampal deep brain stimulation in patients with drug-resistant temporal lobe epilepsy.

Temporal lobe epilepsy patients treated with hippocampal deep brain stimulation (Hip-DBS) have rarely been reported before. Preoperative and postoperative cognitive function is seldom analyzed. Seven patients with drug-resistant temporal lobe epilepsy were included in this study. Bilateral Hip-DBS was performed in these patients. The stimulator was activated 1month after the implantation. Then, the patients returned for further adjustments 4months after the surgery and reprogramming every year. The seizure frequency, Wechsler Adult Intelligence Scale-IV, and Wechsler memory scale-IV were assessed blindly as the outcomes at each follow-up. After a mean 48-month follow-up, the mean seizure frequency significantly decreased (p = 0.011, paired t test; decrease of 78.1%). One patient (14.3%) was seizure-free by the last follow-up; six of seven (85.7%) patients had reductions in seizure frequency of at least 50%; one patient (14.3%) who did not comply with the antiepileptic drug instructions had a less than 50% reduction in seizure frequency. In addition, there were no significant decreases in intelligence or verbal and visual memory from baseline to the last follow-up (p = 0.736, paired t test; p = 0.380, paired t test, respectively). Hip-DBS could provide acceptable long-term efficacy and safety. For patients with drug-resistant temporal lobe epilepsy who are not suitable for resective surgery, Hip-DBS could become a potential therapeutic option.

Not so fast! Limitations of processing speed and working memory indices as embedded performance validity tests in a mixed neuropsychiatric sample

ABSTRACT Introduction Validity indicators embedded within standard neuropsychological tests have received increasing attention as more efficient measures for sampling performance validity throughout an evaluation. This cross-sectional study examined multiple performance validity tests (PVTs) embedded in the Wechsler Adult Intelligence Scale-IV (WAIS-IV) Working Memory (WMI) and Processing Speed (PSI) Indices for detecting invalid test performance. Method This cross-sectional study examined data from a mixed clinical neuropsychiatric sample of 110 patients referred for outpatient evaluation. The sample was composed of 85 patients with valid neuropsychological performance and 25 with invalid performance based on multiple independent criterion PVTs. Among the patients with valid performance, 54% were cognitively impaired, whereas 46% were cognitively unimpaired. Results Among the overall sample, performance on WMI, PSI, and 3/4 constituent subtests (i.e., Digit Span, Symbol Search, Coding) was significantly worse among the invalid group compared to the valid group (ηp 2 =.06–.16) with areas under the curve (AUCs) of.67–.76 and 24–32% sensitivity (≥88% specificity) for identifying invalid performance at cut-scores that maximized accuracy. When the sample was subdivided by cognitive impairment status, AUCs of.68–.87 and 36–56% sensitivity (≥87% specificity) for detecting invalidity at cut-scores that maximized accuracy were found among those without cognitive impairment. In contrast, for patients with cognitive impairment, Digit Span, Arithmetic, WMI, and Coding were nonsignificant, and AUCs of.66–.67. Further, notably reduced sensitivities of 16–28% (≥91% specificity) were found for the remaining significant indices. Conclusion Overall, results indicated that embedded WAIS-IV WMI and PSI are useful embedded PVTs in conditions in which cognitive impairment is not expected; however, these embedded PVTs demonstrated questionable utility among patients with cognitive impairment due to poor sensitivity, if adequate specificity is maintained, suggesting limited efficacy among patients with cognitive impairment due to risk of false-positive classification.

Cognitive function and its relationship with brain structure in myotonic dystrophy type 1.

Studies have shown relationships between white matter abnormalities and cognitive dysfunction in myotonic dystrophy type 1 (DM1), but comprehensive analysis of potential structure-function relationships are lacking. Fifty adult-onset DM1 individuals (33 female) and 68 unaffected adults (45 female) completed the Wechsler Adult Intelligence Scale-IV (WAIS-IV) to determine the levels and patterns of intellectual functioning. Neuroimages were acquired with a 3T scanner and were processed with BrainsTools. Regional brain volumes (regions of interest, ROIs) were adjusted for inter-scanner variation and intracranial volume. Linear regression models were conducted to assess if group by ROI interaction terms significantly predicted WAIS-IV composite scores. Models were adjusted for age and sex. The DM1 group had lower Perceptual Reasoning Index (PRI), Working Memory Index (WMI), and Processing Speed Index (PSI) scores than the unaffected group (PRI t(113) =-3.28, p=0.0014; WMI t(114) =-3.49, p=0.0007; PSI t(114) =-2.98, p=0.0035). The group by hippocampus interaction term was significant for both PRI and PSI (PRI (t(111) =-2.82, p=0.0057; PSI (t(112) =-2.87, p=0.0049)). There was an inverse association between hippocampal volume and both PRI and PSI in the DM1 group (the higher the volume, the lower the intelligence quotient scores), but no such association was observed in the unaffected group. Enlarged hippocampal volume may underlie some aspects of cognitive dysfunction in adult-onset DM1, suggesting that increased volume of the hippocampus may be pathological.

Visual versus Verbal Working Memory in Statistically Determined Patients with Mild Cognitive Impairment: On behalf of the Consortium for Clinical and Epidemiological Neuropsychological Data Analysis (CENDA).

Previous research in mild cognitive impairment (MCI) suggests that visual episodic memory impairment may emerge before analogous verbal episodic memory impairment. The current study examined working memory (WM) test performance in MCI to assess whether patients present with greater visual versus verbal WM impairment. WM performance was also assessed in relation to hippocampal occupancy (HO), a ratio of hippocampal volume to ventricular dilation adjusted for demographic variables and intracranial volume. Jak etal. (2009) (The American Journal of Geriatric Psychiatry, 17, 368-375) and Edmonds, Delano-Wood, Galasko, Salmon, & Bondi (2015) (Journal of Alzheimer's Disease,47(1), 231-242) criteria classify patients into four groups: little to no cognitive impairment (non-MCI); subtle cognitive impairment (SCI); amnestic MCI (aMCI); and a combined mixed/dysexecutive MCI (mixed/dys MCI). WM was assessed using co-normed Wechsler Adult Intelligence Scale-IV (WAIS-IV) Digit Span Backwards and Wechsler Memory Scale-IV (WMS-IV) Symbol Span Z-scores. Between-group analyses found worse WMS-IV Symbol Span and WAIS-IV Digit Span Backwards performance for mixed/dys MCI compared to non-MCI patients. Within-group analyses found no differences for non-MCI patients; however, all other groups scored lower on WMS-IV Symbol Span than WAIS-IV Digit Span Backwards. Regression analysis with HO as the dependent variable was statistically significant for WMS-IV Symbol Span performance. WAIS-IV Digit Span Backwards performance failed to reach statistical significance. Worse WMS-IV Symbol Span performance was observed in patient groups with measurable neuropsychological impairment and better WMS-IV Symbol Span performance was associated with higher HO ratios. These results suggest that visual WM may be particularly sensitive to emergent illness compared to analogous verbal WM tests.

Direct Comparison of Multidimensional Clinical Assessment Tools: Sensitivity to Concussion in Student Athletes

Abstract Purpose Consensus guidelines recommend multidimensional assessment for concussion diagnosis and management. Among cognitive, oculomotor, and postural stability, it remains unclear which modalities perform best in the acute/subacute periods. We conducted a direct comparison to identify those with the strongest sensitivity to sport-related concussion. Methods High school and collegiate football players (aged 14–24) completed preseason baseline assessments. Concussed (n=91) and matched non-concussed teammates (n=85) underwent repeat testing at 48 hours, 8 days, and 15 days post-injury. Postconcussive symptoms (SCAT-3 symptom severity), cognition (Standardized Assessment of Concussion, Immediate Post-Concussion and Cognitive Testing, Trail Making Test, Wechsler Adult Intelligence Scale-IV Processing Speed Index), oculomotor functioning (King-Devick Test), and postural stability (Balance Error Scoring System) were compared using Cohen’s d and Receiver Operating Characteristic analyses. Results Symptom severity had the greatest sensitivity at 48 hours and 8 days post-injury (Cohen’s d=1.43 and 0.53, AUC=.93 and .63, p&lt;.01). Of the performance-based assessments, BESS was most sensitive to SRC at 48 hours post-injury (Cohen’s d=.74, AUC=.70, p&lt;.01). Oculomotor and cognitive testing via ImPACT, WAIS-IV PSI, and TMT-A were sensitive to a lesser degree (Cohen’s d=.35–.58, p&lt;.05). Verbal memory was the only significant performance-based assessment at days 8 and 15, with small-to-medium effect sizes (Cohen’s d=.37 and .44, p&lt;.05). Other cognitive measures (SAC, TMT-B) were not sensitive to SRC across timepoints (p&gt;.05). Conclusion We observed heterogeneity in clinical assessment performance such that the clinical domains strongest in the initial days post-injury (symptom severity, balance) were less sensitive at later follow-up, supporting the potential need for multidimensional assessment.

Visuospatial processing bias in ADHD: A potential artifact in the Wechsler Adult Intelligence Scale and the Rorschach Inkblots Test.

Global processing bias is the automatic tendency to process the global picture before processing the local details. Recent studies suggest that individuals with attention-deficit/hyperactivity disorder (ADHD) show a lack of global processing bias. In the current study, we examined whether lack of global processing bias affects performance on 2 psychological tests, Wechsler Adult Intelligence Scale IV (WAIS-IV) and the Rorschach inkblots test, which require the use of visuospatial processing while measuring different psychological constructs. Adult participants (30 ADHD and 30 typically developing controls) completed the subtests of the WAIS-IV, which rely on visuospatial components, and the Rorschach inkblots test. We found no indication of differences in general fluid intelligence between the groups. On the WAIS-IV test, ADHD participants consistently exhibited superior performance on tasks that relied on local processing and inferior performance on tasks that relied on global processing when compared with healthy controls. On the Rorschach inkblots test, ADHD participants exhibited more responses that referred to local aspects (part/s) of the stimulus and fewer responses that referred to global aspects (whole) of the stimulus. These findings imply that when patients with ADHD are given psychological tests that require visuospatial processing, a potential confound of visuospatial processing style needs to be considered. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

T2*-weighted MRI values correlate with motor and cognitive dysfunction in Parkinson's disease

Brain iron load is one of the main neuropathologic hallmarks of Parkinson's disease (PD). Previous studies indicated that iron in the substantia nigra (SN) is related to disease duration and motor impairment. We explore, through a cross-sectional study, the association between brain iron distribution, evaluated by T2*-weighted magnetic resonance imaging (T2*), and clinical features in a cohort of patients with PD. Thirty-two patients with PD, compared with 10 control subjects, were evaluated for motor and cognitive features (attention and working memory, executive functions, language, memory, and visuospatial function). They underwent a magnetic resonance imaging protocol including T2* analysis of specific brain regions of interest to measure iron load compared with healthy control subjects. We found that iron content of the SN correlated positively with both disease duration and Unified Parkinson's Disease Rating Scale III off score. Montreal Cognitive Assessment, Spatial Span, and Graded Naming Test scores were inversely associated with iron load of the SN, whereas Wechsler Adult Intelligence Scale-IV Similarities score showed an inverse relationship with iron content in all the regions of interest examined. Our findings suggest a relationship between topographic brain iron distribution and cognitive domain impairment.

Factors Associated with Māori Performance on the WAIS-IV.

Neuropsychological tests are routinely used to assess Māori, the indigenous people of New Zealand, yet very few investigations of the psychometric properties of these tests with this population have been conducted. This paper focuses on factors that may impact performance of Māori adults on neuropsychological testing. The Wechsler Adult Intelligence Scale-IV (WAIS-IV) was administered to a sample of 284 Māori stratified for age (between 16 years and 90 years) and gender in order to establish a Māori normative data set. The sample who primarily spoke English as their first language were recruited from a range of urban, regional and rural areas in New Zealand to obtain representation of the main Māori Iwi (tribes). Analysis of test results suggests acculturation, education, income, and, "a culturally positive experience" may have accounted for some of the variance in test performance.

Clinical and demographic correlates of apathy in Parkinson's disease.

To better understand the demographic, neuropsychiatric, cognitive, and motor predictors of apathy in Parkinson's disease (PD). 112 participants (Mage = 68.53 years; Mdisease duration = 6.17years) were administered the Apathy Scale (AS), Beck Depression Inventory-II (BDI-II), Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Trail Making Test (TMT), Wechsler Adult Intelligence Scale-IV Matrix Reasoning subtest, letter (F-A-S) and category (Animals) fluency, and Hopkins Verbal Learning Test-Revised. Psychosis was assessed. A stepwise logistic regression analysis was performed to investigate the ability of demographic factors and clinical assessments to predict nonapathetic (AS ≤ 13) versus apathetic (AS > 13) group membership. The regression analysis yielded a robust model in which older age, less education, elevated BDI-II, current psychosis, higher MDS-UPDRS PartIII (motor score), and slower TMT-B performance predicted membership in the apathetic group, with a correct classification rate of 77.5% (Nagelkerke R2 = 0.48, p < .001). Depression (OR = 9.20, p < .001) and education (OR = 0.66, p = 0.002) contributed significantly to the overall model. A linear regression with AS score as the outcome variable was similar, but TMT-B additionally contributed significantly (p = 0.02) to the overall model, F(6, 86) = 12.02, p < .001, adjusted R2 = 0.42. Of the factors examined, depression, education, and executive functioning were the strongest correlates of apathy in PD. These results support the idea that common underlying frontosubcortical disruptions in this population contribute to apathy, depression, and executive dysfunction.

Myelin water imaging of moderate to severe diffuse traumatic brain injury.

Traumatic axonal injury (TAI), a signature injury of traumatic brain injury (TBI), is increasingly known to involve myelin damage. The objective of this study was to demonstrate the clinical relevance of myelin water imaging (MWI) by first quantifying changes in myelin water after TAI and then correlating those changes with measures of injury severity and neurocognitive performance. Scanning was performed at 3 months post-injury in 22 adults with moderate to severe diffuse TBI and 30 demographically matched healthy controls using direct visualization of short transverse component (ViSTa) MWI. Fractional anisotropy (FA) and radial diffusivity (RD) were also obtained using diffusion tensor imaging. Duration of post-traumatic amnesia (PTA) and cognitive processing speed measured by the Processing Speed Index (PSI) from Wechsler Adult Intelligence Scale-IV, were assessed. A between-group comparison using Tract-Based Spatial Statistics revealed that there was a widespread reduction of apparent myelin water fraction (aMWF) in TBI, consistent with neuropathology involving TAI. The group difference map of aMWF yielded topography that was different from FA and RD. Importantly, aMWF demonstrated significant associations with PTA (r = −0.564, p = .006) and PSI (r = 0.452, p = .035). In conclusion, reduced myelin water, quantified by ViSTa MWI, is prevalent in moderate-to-severe diffuse TBI and could serve as a potential biomarker for injury severity and prediction of clinical outcomes.

Modality-Specific Working Memory Systems Verified by Clinical Working Memory Tests.

ObjectiveThis study was to identify whether working memory (WM) can be clearly subdivided according to auditory and visual modality. To do this, we administered the most recent and universal clinical WM measures in a mixed psychiatric sample.MethodsA total of 115 patients were diagnosed on the basis of DSM-IV diagnostic criteria and with MINI-Plus 5.0, a structured diagnostic interview. WM subtests of Korean version of Wechsler Adult Intelligence Scale-IV and Korean version of Wechsler Memory Scale-IV were administered to assess WM. Confirmatory factor analysis (CFA) was used to observe whether WM measures fit better to a one-factor or two-factor model.ResultsCFA results demonstrated that a two factor model fits the data better than one-factor model as expected.ConclusionOur study supports a modality model of WM, or the existence of modality-specific WM systems, and thus poses a clinical significance of assessing both auditory and visual WM tests.

Local structural connectivity is associated with social cognition in autism spectrum disorder.

The current theory implying local, short-range overconnectivity in autism spectrum disorder, contrasting with long-range underconnectivity, is based on heterogeneous results, on limited data involving functional connectivity studies, on heterogeneous paediatric populations and non-specific methodologies. In this work, we studied short-distance structural connectivity in a homogeneous population of males with high-functioning autism spectrum disorder and used a novel methodology specifically suited for assessing U-shaped short-distance tracts, including a recently developed tractography-based atlas of the superficial white matter fibres. We acquired diffusion-weighted MRI for 58 males (27 subjects with high-functioning autism spectrum disorder and 31 control subjects) and extracted the mean generalized fractional anisotropy of 63 short-distance tracts. Neuropsychological evaluation included Wechsler Adult Intelligence Scale IV (WAIS-IV), Communication Checklist-Adult, Empathy Quotient, Social Responsiveness Scale and Behaviour Rating Inventory of Executive Function-Adult (BRIEF-A). In contradiction with the models of short-range over-connectivity in autism spectrum disorder, we found that patients with autism spectrum disorder had a significantly decreased anatomical connectivity in a component comprising 13 short tracts compared to controls. Specific short-tract atypicalities in temporal lobe and insula were significantly associated with clinical manifestations of autism spectrum disorder such as social awareness, language structure, pragmatic skills and empathy, emphasizing their importance in social dysfunction. Short-range decreased anatomical connectivity may thus be an important substrate of social deficits in autism spectrum disorder, in contrast with current models.

Education, and the balance between dynamic and stationary functional connectivity jointly support executive functions in relapsing-remitting multiple sclerosis.

Graphical network characteristics and nonstationary functional connectivity features, both derived from resting-state functional magnetic resonance imaging (rsfMRI) data, have been associated with cognitive performance in healthy subjects. How these features jointly relate to cognition in diseased states has not been investigated. In this study, 46 relapsing-remitting multiple sclerosis subjects underwent rsfMRI scans and a focused cognitive battery. With a sliding window approach, we examined six dynamic network features that indicated how connectivity changed over time as well as six measures derived from graph theory to reflect static network characteristics. Multiset canonical correlation analysis (MCCA) was then carried out to investigate the relations between dynamic network features, stationary network characteristics, cognitive testing, demographic, disease severity, and mood. Multiple sclerosis (MS) subjects demonstrated weaker connectivity strength, decreased network density, reduced global changes, but increased changes in interhemispheric connectivity compared to controls. The MCCA model determined that executive functions and processing speed ability measured by Wechsler Adult Intelligence Scale IV (WAIS-IV) Working Memory Index, WAIS-IV Processing Speed Index, and the Verbal Fluency Test were positively correlated with education, dynamic connectivity, and static connectivity strength; while poor task switching was correlated with disease severity, psychiatric comorbidities such as depression, anxiety, and fatigue, and static network density. Taken together, our results suggest that better executive functioning in MS requires maintenance of a continued coordination between stationary and dynamic functional connectivity as well as the support of education, and dynamic functional connectivity may provide an additional cognitive biomarker of disease severity in the MS population.