Deficits In Information Processing Speed Research Articles

Symbol Digit Modalities Test in progressive multiple sclerosis.

The Symbol Digit Modalities Test (SDMT) is a highly sensitive neuropsychological tool used for the assessment of information processing speed (IPS) in various neurological disorders. In this review, we have focused on the current knowledge regarding the use of SDMT selectively in the evaluation of progressive multiple sclerosis (PMS) patients. A literature review was performed regarding the application of SDMT in PMS, with a focus on the primary progressive and secondary progressive subtypes. Relationships of diverse disease-associated factors with SDMT have been described, including disease course, imaging findings, molecular biomarkers, treatment and others. SDMT is a very useful and easily applicable instrument in the diagnostic armamentarium of neurologists and neuropsychologists. It is especially valuable in the evaluation of PMS patients, in whom the prevalence of IPS deficits is higher than in relapsing-remitting multiple sclerosis subjects or in healthy individuals. An emphasis should be laid on larger study groups and differentiating between individual PMS subtypes and their separate analysis in the context of cognitive assessment.

Predicting risk of dementia among the elderly with major depressive disorder in remission: A prospective study.

Cognitive impairment and change are a focus of research into late-life depression. The aims of this 5-year prospective study were (1) to observe cognitive status change; (2) to investigate the rate and risk ratio of dementia or cognitive decline; and (3) to examine the cognitive domain predictors for conversion to dementia within 5years among a clinical cohort with remitted major depressive disorder (MDD). The study cohort included 130 elderly persons with late-life remitted MDD and 100 normal controls. Comprehensive neuropsychological tests were conducted to determine cognitive domain status. Diagnoses of mild cognitive impairment (MCI) and dementia were made at baseline and at a follow-up visit at the 5-year point. In total, 98 cases and 55 normal controls completed the 5-year follow-up assessment. Of the study cohort with late-life remitted MDD, 28.6% had MCI and 25.5% developed dementia within 5years. Patients with late-life remitted MDD had an approximate 3 times higher risk of subsequent cognitive decline as compared with the normal controls. Information-processing speed (p=0.009) and memory (p=0.041) could predict subsequent progression to dementia within 5years among patients with MDD. This study demonstrated that compared with the general elderly population, elderly patients with depression have more significant impairment in cognitive function after 5years. Further, we found that in depressed patients, deficits in information-processing speed and memory domains were highly suggestive of progression to dementia within 5years.

Relationship between emotion recognition and cognition in multiple sclerosis: a meta-analysis protocol

IntroductionMultiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease of the central nervous system characterised by a broad and unpredictable range of symptoms, including cognitive and socio-cognitive dysfunction. Alongside...

88 Social Cognition and Information Processing Speed in Individuals with Multiple Sclerosis and Co-Morbid Diabetes: An Interim Analysis

Objective:Multiple sclerosis (MS) is associated with cognitive and social cognitive deficits. Social cognition impairments may include difficulty with facial expression and emotion recognition. People with MS (PwMS) may also not be aware of their cognitive challenges as demonstrated through discrepant objective and subjective assessments. Research recently conducted in demyelinated mouse models demonstrated that metformin, a drug typically used to treat type II diabetes mellitus (DMII), promotes remyelination and reverses existent social cognition impairment by repressing the monoacylglycerol lipase (MgII) enzyme in the brain. We aim to translate this basic science research and are conducting a pilot study to determine if metformin improves social cognition in PwMS. This project will compare social cognition in those with MS and comorbid DMII who are treated with metformin and those who are not. For the purposes of this interim data analysis, we collapse across both MS groups who are, and who are not, treated with metformin. The current objective is to evaluate the relationship between subjective (i.e., perceived empathy), objective social cognition and information processing speed (IPS) in PwMS and co-morbid diabetes.Participants and Methods:Preliminary data on 15 PwMS are included. Participants completed a demographic questionnaire, a cognitive assessment battery, an objective social cognition assessment and self-report questionnaires. These questionnaires assessed subjective social cognition, fatigue, mood, and disability level.Results:Preliminary results showed that IPS was positively correlated with the affective empathy domain of social cognition, r = .53, p = .04. Additionally, IPS was positively correlated with objective social cognition, r = .71, p = 003. Follow-up regression analyses demonstrated that IPS predicted objective social cognition, R2 = .71, SE = 3.04, F(1,13) = 13.36, p = .003 and subjective social cognition, R2 = .53, SE = 5.39, F(1,13) = 4.97, p = .04. However, subjective and objective measures of social cognition were not correlated, p > .05 and remained uncorrelated when IPS was controlled for, p > .05.Conclusions:A majority of the variance in social perception is explained by IPS, suggesting that how quickly one can think may be a fundamental cognitive process to allow optimal functioning in social situations. While the reason for the relationship between IPS and subjective social cognition is perhaps less apparent, it may reflect a more global cognitive compromise that impacts both cognitive and social processes. This lends support to the Relative Consequence Model that suggests IPS deficits are a fundamental cognitive deficit underlying other more complex cognitive processes. The lack of correlation between subjective perception of empathy and objective social cognition requires further exploration and could potentially be related to some individuals with MS having a diminished ability to judge their own social proficiency. Further analyses with a larger sample will be conducted to assess group differences in social cognitive outcomes and MgII levels between metformin and non-metformin groups. If PwMS who take metformin have better social cognition compared to PwMS who do not take metformin, Mgll levels can be used as a biomarker to guide metformin treatment with the goal of improving social cognition.

Cortical Thickness and Brain Connectivity Mediate the Relation Between White Matter Hyperintensity and Information Processing Speed in Cerebral Small Vessel Disease.

White matter hyperintensities of presumed vascular origin (WMH) are the most common imaging feature of cerebral small vessel disease (cSVD) and are associated with cognitive impairment, especially information processing speed (IPS) deficits. However, it is unclear how WMH can directly impact IPS or whether the cortical thickness and brain connectivity mediate such association. In this study, it was evaluated the possible mediating roles of cortical thickness and brain (structural and functional) connectivity on the relationship between WMH (also considering its topography distribution) and IPS in 389 patients with cSVD from the RUN-DMC (Radboud University Nijmegen Diffusion tensor and Magnetic resonance imaging Cohort) database. Significant (p < 0.05 after multiple comparisons correction) associations of WMH volume and topography with cortical thickness, brain connectivity, and IPS performance in cSVD individuals were found. Additionally, cortical thickness and brain structural and functional connectivity were shown to mediate the association of WMH volume and location with IPS scores. More specifically, frontal cortical thickness, functional sensorimotor network, and posterior thalamic radiation tract were the essential mediators of WMH and IPS in this clinical group. This study provided insight into the mechanisms underlying the clinical relevance of white matter hyperintensities in information processing speed deficits in cSVD through cortical thinning and network disruptions.

Effect of deep gray matter atrophy on information processing speed in early relapsing-remitting multiple sclerosis.

Cognitive dysfunction, including reduced Information processing speed (IPS), is relatively common in multiple sclerosis(MS). IPS deficits have profound effects on several aspects of patients' life. Previous studies showed that deep gray matter atrophy is highly correlated with overall cognitive impairment in MS. However, the effect of deep gray matter atrophy on IPS deficits is not well understood. In this study, we evaluated the effects of deep gray matter volume changes on IPS in people with early relapse-remitting MS (RRMS) compared to healthy control. In this case-control study, we enrolled 63 case with RRMS and 36 healthy controls. All patients were diagnosed within 6 years. IPS was evaluated using the Integrated Cognitive Assessment (ICA) test. We also performed a 1.5T MRI to evaluate deep gray matter structures. People with RRMS had lower accuracy in the ICA test (p=.01). However, the reaction time did not significantly differ between RRMS and control groups (p=.6). Thalamus volume was significantly lower in the RRMS group with impaired IPS compared to the RRMS with normal IPS and control groups (p<10-4). Other deep gray matter structures were not significantly different between the RRMS with impaired IPS group and the RRMS with normal IPS group. Some people with MS are impaired in IPS even in the early stages of the disease. Thalamic atrophy affected IPS in these patients, however atrophy in other deep gray matter structures, including caudate, putamen, globus pallidus, hippocampus, amygdala, accumbens, and cerebellum, were not significantly correlated with IPS impairment in early RRMS.

OS09.4.A Cognitive functioning of patients with diffuse glioma during stable disease

Abstract Background Glioma patients often experience cognitive problems, which are associated with decreased functional independence and health-related quality of life. However, the prevalence and nature of cognitive impairment in these patients is relatively underreported, particularly during stable disease. In this study we determine the prevalence of cognitive deficits and explore distinct cognitive profiles of patients with diffuse glioma at least two months after tumor treatment. Material and Methods A total of 112 patients (mean age: 43 years) without clinical or radiological progression with a grade II-IV glioma were included in this observational cohort study. Cognitive functioning was assessed in five cognitive domains (attention, information processing speed, verbal memory, working memory, and executive functioning). Cognitive impairment was defined as a z-score of 1.5 SD below that of healthy controls. Hierarchical cluster analysis was used to examine cognitive profiles. Results In total, 46 patients (41%) had cognitive impairment. More than one domain was impaired in 25 of these patients (54%). The domains were affected in decreasing order of frequency: working memory in 31%, information processing speed in 22%, attention in 19%, verbal memory in 12%, and executive functioning in 11% of the patients. A clustered heatmap revealed three prominent cognitive clusters with an increasing number of cognitive domains impaired. The first cluster displayed patients with only working memory deficits, patients in the second cluster also had deficits in information processing speed, and the last cluster showed patients with impairments across all domains. Conclusion Cognitive impairment is highly prevalent in patients with diffuse glioma during stable disease. Working memory and information processing speed are most frequently affected. Importantly, our analyses show evidence for three subgroups in cognitively impaired glioma patients. Working memory seems an important driver in cognitive impairment given the involvement in all subgroups.

QOL-24. Evaluating the diagnostic validity &amp; predictive value of the Cerebellar Cognitive Affective Syndrome (CCAS) in pediatric posterior fossa tumour patients

Abstract OBJECTIVE: The present study aimed to examine the extent of deficits associated with the Cerebellar Cognitive Affective Syndrome (CCAS) in patients treated for paediatric posterior fossa tumours (PFT). Furthermore, we wanted to assess its diagnostic validity and predictive value for late sequelae. METHOD: Neuropsychological test data from 56 PFT patients treated at our pediatric neuro-onocology unit (mean age at treatment: seven years; mean age at first neuropsychological examination: nine years) were examined for severity of deficits in the CCAS core domains of executive functions, verbal functions, visuospatial abilities and emotions/behaviour. Patients with CCAS (n=20) were compared to two control groups without the syndrome (PFT patients treated either surgically (n=18) or surgically followed by radio/chemotherapy (n=18)) in terms of long-term neuropsychological and educational outcomes (mean age: 14 years). We also examined risk factors for CCAS development. RESULTS: The results showed mild to severe impairment in at least one CCAS domain in 55 out of 56 patients. Complete CCAS was diagnosed in 35.7% of cases. Seven years after tumour diagnosis, information processing, logical thinking, verbal functions, visuospatial skills and executive functions were more impaired in CCAS patients than in controls. They also needed more special educational support. Information processing speed was equally poor in CCAS patients and in controls treated with chemotherapy/radiotherapy. A significant association was found between risk factors and deficits in information processing speed, but not with the occurrence of CCAS. CONCLUSION: Deficits in the central CCAS features are common in PFT patients, but in varying degrees, suggesting that it is a continuous syndrome rather than a dichotomous one. However, it is problematic that domains such as information processing speed are not included in the diagnosis. External criteria regarding everyday life should be considered in future studies.

Role of autoantibodies and blood–brain barrier leakage in cognitive impairment in systemic lupus erythematosus

ObjectiveCognitive impairment is common in patients with SLE but the cause is unknown. The current cross-sectional study examined the association between select SLE-related autoantibodies, other serological biomarkers and extensive blood–brain...

Evaluating the diagnostic validity of the cerebellar cognitive affective syndrome (CCAS) in pediatric posterior fossa tumor patients.

BackgroundThe aim of this case-control study was to investigate the severity of the cerebellar cognitive affective syndrome (CCAS) in patients treated for pediatric posterior fossa tumors (PFT) and evaluate its diagnostic validity and predictive value for long-term effects.MethodsUsing neuropsychological test data from 56 patients with PFT (average age: 14 years), the severity of deficits in the CCAS core areas (executive functions, verbal functions, visuospatial abilities and emotions/behaviour) was examined. Neuropsychological and academic long-term outcomes of patients with CCAS were compared to two control groups of PFT patients (treated with either surgery or surgery followed by radio-/chemotherapy) without the syndrome. Risk factors associated with various deficits were considered.ResultsAll but one PFT patient suffered from slight to severe impairments in at least one CCAS domain, while complete CCAS occurred in 35.7%. Seven years after tumor diagnosis CCAS patients performed worse in information processing, logical reasoning, verbal functions, visuospatial skills, and executive functioning and required more special educational support compared to the control groups. CCAS patients performed equally poor as patients treated with chemo-/radiotherapy in tasks measuring information processing speed. Risk factors were significantly associated with deficits in information processing speed but not CCAS emergence.ConclusionsDeficits in the core CCAS domains are commonly found in PFT patients, but varying in severity, which suggests the syndrome to be continuous rather than dichotomous. However, the validity of CCAS diagnosis was low and unspecific. The exclusion of relevant functions typically impaired in PFT patients (eg, information processing) resulted in difficulties being overlooked.

The impact of pandemic-related worry on cognitive functioning and risk-taking.

Here, we sought to quantify the effects of experienced fear and worry, engendered by the COVID-19 pandemic, on both cognitive abilities-speed of information processing, task-set shifting, and proactive control-as well as economic risk-taking. Leveraging a repeated-measures cross-sectional design, we examined the performance of 1517 participants, collected during the early phase of the pandemic in the US (April-June 2020), finding that self-reported pandemic-related worry predicted deficits in information processing speed and maintenance of goal-related contextual information. In a classic economic risk-taking task, we observed that worried individuals' choices were more sensitive to the described outcome probabilities of risky actions. Overall, these results elucidate the cognitive consequences of a large-scale, unpredictable, and uncontrollable stressor, which may in turn play an important role in individuals' understanding of, and adherence to safety directives both in the current crisis and future public health emergencies.

Older age, male sex, and cerebral microbleeds predict white matter loss after traumatic brain injury.

Little is known on how mild traumatic brain injury affects white matter based on age at injury, sex, cerebral microbleeds, and time since injury. Here, we study the fractional anisotropy of white matter to study these effects in 109 participants aged 18-77 (46 females, age μ ± σ = 40 ± 17years) imaged within [Formula: see text] 1week and [Formula: see text] 6months post-injury. Age is found to be linearly associated with white matter degradation, likely due not only to injury but also to cumulative effects of other pathologies and to their interactions with injury. Age is associated with mean anisotropy decreases in the corpus callosum, middle longitudinal fasciculi, inferior longitudinal and occipitofrontal fasciculi, and superficial frontal and temporal fasciculi. Over [Formula: see text] 6months, the mean anisotropies of the corpus callosum, left superficial frontal fasciculi, and left corticospinal tract decrease significantly. Independently of other predictors, age and cerebral microbleeds contribute to anisotropy decrease in the callosal genu. Chronically, the white matter of commissural tracts, left superficial frontal fasciculi, and left corticospinal tract degrade appreciably, independently of other predictors. Our findings suggest that large commissural and intra-hemispheric structures are at high risk for post-traumatic degradation. This study identifies detailed neuroanatomic substrates consistent with brain injury patients' age-dependent deficits in information processing speed, interhemispheric communication, motor coordination, visual acuity, sensory integration, reading speed/comprehension, executive function, personality, and memory. We also identify neuroanatomic features underlying white matter degradation whose severity is associated with the male sex. Future studies should compare our findings to functional measures and other neurodegenerative processes.

Impact of Visual Discomfort Symptoms On SDMT Performance Among Persons With Multiple Sclerosis

<h3>Research Objectives</h3> To examine how visual discomfort symptoms affect performance on the symbol digit modalities test (SDMT), a visually mediated information processing speed task which is considered a gold standard measure for cognition in multiple sclerosis (MS) research. <h3>Design</h3> Observational, cross-sectional study. <h3>Setting</h3> General community. <h3>Participants</h3> Eighty-seven persons with MS and 30 healthy controls (HCs). <h3>Interventions</h3> Not applicable. <h3>Main Outcome Measures</h3> Visual discomfort questionnaire (VDQ) and SDMT. <h3>Results</h3> Persons with MS reported significantly more severe visual discomfort symptoms on the VDQ than HCs (W = 424, p < 0.001). More severe visual discomfort symptoms was significantly associated with worse SDMT performance (ρ = -0.24, p = 0.011). Specifically, reports of symptoms such as text moving or fading while reading (p = 0.038), blurriness and diplopia (p = 0.055), having to re-read texts (p = 0.076), and slow reading (p = 0.008) were significantly related to SDMT performance, while symptoms related to headache and eye soreness (p = 0.824) and glare (p = 0.961) were not linked to SDMT performance. <h3>Conclusions</h3> Visual discomfort symptoms may impact/interfere with SDMT performance in persons with MS. When determining information processing speed deficits using the SDMT, visual discomfort symptoms need to be considered. <h3>Author(s) Disclosures</h3> Authors declare no conflicts of interest.

A Meta-analysis of Dynamic Prevalence of Cognitive Deficits in the Acute, Subacute, and Chronic Phases After Traumatic Brain Injury.

BACKGROUND: Reports regarding prevalence of post-traumatic brain injury (TBI) cognitive deficits were inconsistent. We aimed to synthesize the prevalence of cognitive deficits after TBI in the acute, subacute, and chronic phases. METHODS: PubMed, EMBASE, and ProQuest Dissertations and Theses A&I databases were searched from the inception to April 27, 2020. Studies with prospective, retrospective, and cross-sectional designs reporting the prevalence of cognitive deficits after TBI in adults were included. RESULTS: A total of 15 articles were included for prevalence estimation. The pooled prevalence of memory and attention deficits after mild TBI was 31% and 20% in the acute phase and 26% and 18% in the subacute phase, respectively, and 49% and 54% in the subacute phase and 21% and 50% in the chronic phase after moderate-to-severe TBI. The overall prevalence of information processing speed deficits after mild TBI in the acute and subacute phases was 21% and 17%, respectively, and 57% in the chronic phase after moderate-to-severe TBI. The overall prevalence of executive dysfunction in the subacute and chronic phases was 48% and 38%, respectively, after moderate-to-severe TBI. CONCLUSION: Cognitive deficits are prevalent in the acute to chronic phases after TBI. Healthcare providers should design effective intervention targeting cognitive impairment after TBI as early as possible.

Identification of specific neural circuit underlying the key cognitive deficit of remitted late-onset depression: A multi-modal MRI and machine learning study

Neuropsychological impairment is a key feature of late-onset depression (LOD), with deficits observed across multiple cognitive domains. And this neuropsychological impairment can persist even after the remission of depressive symptoms. However, none of previous studies have explored the pattern of cognitive deficit in remitted LOD (rLOD), and investigated the specific neural circuit underlying the key cognitive deficit of LOD. 40 rLOD patients and 36 controls underwent comprehensive neuropsychological assessments and magnetic resonance imaging (MRI) scans. The influence of executive function or information processing speed deficit on other cognitive domains was first investigated. We then applied a multivariate machine learning technique known as relevance vector regression to evaluate the potential of multiple-modal MRI (i.e., integrating whole-brain grey-matter [GM] volume and white-matter [WM] tract features) for making accurate predictions about the key cognitive deficit for individual rLOD patient. We revealed that the information processing speed appears to represent a key cognitive deficit in rLOD. Further the machine learning model identified a wide range of GM regions and WM tracts that significantly contributed to the prediction of individual performance on information processing speed (r = 0.50, P < 0.001). The GM regions mainly located in the frontal-subcortical and limbic systems; and the WM tracts mainly located in the frontal-limbic pathway, including the anterior corona radiata, fornix, posterior cingulate bundle, and uncinate fasciculus. This present study provide strongly evidence supporting the concept of rLOD that the core aspect of the cognitive deficits (i.e., information processing speed) is associated with disruption of the frontal-subcortical-limbic pathway.

Non-classical behavior of the default mode network regions during an information processing task

The default mode network (DMN) efficient deactivation and suppressed functional connectivity (FC) during goal-directed tasks, which require attentional resources, have been considered essential to healthy brain cognition. However, recent studies have shown that DMN regions do not always show the expected behavior. Then, we aimed to investigate the functional activation and connectivity of DMN nodes in young, healthy controls during a goal-directed task. We used an adaptation of the symbol digit modalities test (SDMT) to evaluate the information processing speed (IPS). Twenty-four subjects (10 women, age: 29 ± 7years) underwent two functional Magnetic Resonance Imaging experiments: one during resting-state and one during a block-designed SDMT paradigm. We superimposed the templates of the DMN on the group activation map and observed the reorganization of the network. For the posterior cingulate cortex (PCC) node of the DMN, which is spatially extensive, comprising the precuneus (dorsal portion) and the posterior cingulate gyrus (PCG, ventral portion), the extent of each region was different between conditions, suggesting different functional roles for them. Therefore, for the functional connectivity (FC) analysis, we split the DMN-PCC region into two regions: left precuneus (BA 7) and PCG. The left precuneus (BA 7) was positively correlated with the left lingual gyrus (BA 17), a task-positive region, and negatively associated with the DMN nodes when comparing task performance with the resting-state condition. The other DMN regions presented the classical antagonistic role during the attentional task. In conclusion, we found that the activation and functional connectivity of the DMN is, in general, suppressed during the information processing. However, the left precuneus BA 7 presented a context-dependent modulatory behavior, working as a transient in-between hub connecting the DMN to task-positive areas. Such findings support studies that show increased activation and excitatory functional connectivity of DMN portions during goal-directed tasks. Moreover, our results may contribute to defining more precise functional correlates of IPS deficits in a wide range of clinical and neurological diseases.

Effects of HIV infection, antiretroviral therapy, and immune status on the speed of information processing and complex motor functions in adult Cameroonians

HIV-associated neurocognitive deficits include impaired speed-of-information processing (SIP) and motor functions. There is lack of Cameroonian adult norms for assessing SIP or motor functions. This study of 683 Cameroonians (320 HIV+, 363 HIV−) establishes demographically-adjusted norms for six SIP [Wechsler-Adult-Intelligence-Scale (WAIS)-III Digit Symbol (WAIS-IIIDS) and Symbol Search (WAIS-IIISS), Stroop Color-Naming, Stroop Word-Reading, Trail-Making Test-A (TMT-A), Color Trails-1 (CTT1)], and two motor function [Grooved Pegboard-dominant (GP-DH) and non-dominant (GP-NDH) hands] tests. We assessed viral effects on SIP and motor functions. HIV-infected persons had significantly lower (worse) T scores on GP-DH, WAIS-IIIDS, Stroop Word-Reading, TMT-A; lower motor and SIP summary T scores. Significantly higher proportion of cases (20.7%) than controls (10.3%) had impaired SIP. Male cases had better T scores than female cases on GP-NDH, WAIS-IIIDS, WAIS-IIISS, TMT-A, CTT1; better SIP summary T scores. Antiretroviral therapy (ART) was associated with significantly better T scores on GP-NDH, WAIS-IIIDS, Stroop Color-Naming; better motor and SIP summary T scores. Cases with higher CD4 had better T scores on WAIS-IIIDS, TMT-A, CTT1; better SIP summary T scores. Overall, we demonstrate that HIV infection in Cameroon is associated with deficits in SIP and motor functions; ART and higher CD4 are associated with better cognitive performance. We provide SIP and psychomotor functions normative standards, which will be useful for neurobehavioral studies in Cameroon of diseases affecting the brain.

Strategic white matter injury associated with long-term information processing speed deficits in mild traumatic brain injury.

Deficits in information processing speed (IPS) are among the earliest and most prominent cognitive manifestations in mild traumatic brain injury (mTBI). We investigated the impact of white matter fiber location on IPS outcome in an individual basis assessment. A total of 112 acute mild TBI with all CT negative underwent brain DTI and blood sampling for inflammation cytokines within 7 days postinjury and 72 age‐ and sex matched healthy controls with same assessments were enrolled. IPS outcome was assessed by the trail making test at 6–12 month postinjury in mild TBI. Fractional anisotropy (FA) features were extracted using a novel lesion‐load analytical strategy to capture spatially heterogeneous white matter injuries and minimize implicit assumptions of uniform injury across diverse clinical presentations. Acute mild TBI exhibited a general pattern of increased and decreased FA in specific white matter tracts. The power of acute FA measures to identify patients developing IPS deficits with 92% accuracy and further improved to 96% accuracy by adding inflammation cytokines. The classifiers predicted individual's IPS and working memory ratings (r = .74 and .80, respectively, p < .001). The thalamo‐cortical circuits and commissural tracts projecting or connecting frontal regions became important predictors. This prognostic model was also verified by an independent replicate sample. Our findings highlighted damage to frontal interhemispheric and thalamic projection fiber tracts harboring frontal‐subcortical neuronal circuits as a predictor for processing speed performance in mild TBI.

Slowed Information Processing Speed at Four Years Poststroke: Evidence and Predictors from a Population-Based Follow-up Study

Background and PurposeSlowed Information Processing Speed (IPS) is a commonly reported cognitive deficit following stroke, affecting up to 50% to 70 % of stroke survivors. IPS has a major influence on poststroke cognitive dysfunction, affecting quality of life and increasing dependence on others. Few studies have examined predictors of slow IPS after stroke, and there is a paucity of data in terms of long-term prevalence. This study examined baseline predictors associated with long-term slow IPS in a population-based stroke incidence cohort, 4 years after stroke onset. MethodsAdults with stroke (n = 133, m = 71.1 ± 13.5 years) completed the Symbol Digit Modalities Test (SDMT) at 4 years poststroke. Baseline predictors were obtained within 2 weeks of the acute event. Multivariate regression linear and logistic models were used to identify baseline predictors (reported as OR with 95%CI) and prevalence of impaired IPS at 4-years. Results51% of people with stroke had low scores on the SDMT as indicated by a score of −1.0 SD to −2.5 SD (ranging from low to very low respectively). There were significant associations between slow IPS at 4-years after controlling for age and education level and the following baseline factors: older age (>75 years) (OR 3.03, 95% CI .9-9.3,P = .05), previous stroke (OR 2.74, 95% CI 1.0-7.4,P = .05), high cholesterol (OR 2.72, 95% CI 1.3-5.4,p = .01), hypertension (OR 1.82, 95% CI 0.9-3.6,p = .05), and presence of coronary artery disease (OR 3.35, 95% CI 1.6-9.6,P = .01), or arrhythmia (OR 4.40, 95% CI 1.5-12.4,P = .01). ConclusionsEven after 4-years poststroke, slowed IPS is highly prevalent, with comorbid vascular risk factors significantly contributing to persistent impaired IPS. Early identification of adults who are at higher risk of deficits in IPS is vital to targeting the timely delivery of cognitive rehabilitation interventions, improving overall outcomes.

Cognitive processing speed deficits in multiple sclerosis: Dissociating sensorial and motor processing changes from cognitive processing speed

BackgroundThe assessment of cognitive information processing speed (IPS) is complicated in MS, with altered performance on tests such as the Symbol Digit Modalities Test (SDMT) potentially representing changes not only within cognitive networks but in the initial sensorial transmission of information to cognitive networks, and/or efferent transmission of the motor response. ObjectiveWe aimed to isolate and characterise cognitive IPS deficits in MS using ocular motor tasks; a prosaccade task (used to assess and control for sensorial and motor IPS) which was then used to adjust performance on the Simon task (cognitive IPS). MethodsAll participants (22 MS patients with early disease, 22 healthy controls) completed the ocular motor tasks and the SDMT. The Simon task assessed cognitive IPS by manipulating the relationship between a stimulus location and its associated response direction. Two trial types were interleaved: (1) congruent, where stimulus location = response direction; or (2) incongruent, where stimulus location ≠ response direction. RESULTS MS patients did not perform differently to controls on the SDMT. For OM tasks, when sensorial and motor IPS was controlled, MS patients had significantly slower cognitive IPS (incongruent trials only) and poorer conflict resolution. SDMT performance did not correlate with slower cognitive IPS in MS patients, highlighting the limitation of using SDMT performance to interpret cognitive IPS changes in patients with MS. ConclusionCognitive IPS deficits in MS patients are dissociable from changes in other processing stages, manifesting as impaired conflict resolution between automatic and non-automatic processes. Importantly, these results raise concerns about the SDMT as an accurate measure of cognitive IPS in MS.