Measures Of Information Processing Speed Research Articles

Functional gradients reveal cortical hierarchy changes in multiple sclerosis

AbstractFunctional gradient (FG) analysis represents an increasingly popular methodological perspective for investigating brain hierarchical organization but whether and how network hierarchy changes concomitant with functional connectivity alterations in multiple sclerosis (MS) has remained elusive. Here, we analyzed FG components to uncover possible alterations in cortical hierarchy using resting‐state functional MRI (rs‐fMRI) data acquired in 122 MS patients and 97 healthy control (HC) subjects. Cortical hierarchy was assessed by deriving regional FG scores from rs‐fMRI connectivity matrices using a functional parcellation of the cerebral cortex. The FG analysis identified a primary (visual‐to‐sensorimotor) and a secondary (sensory‐to‐transmodal) component. Results showed a significant alteration in cortical hierarchy as indexed by regional changes in FG scores in MS patients within the sensorimotor network and a compression (i.e., a reduced standard deviation across all cortical parcels) of the sensory‐transmodal gradient axis, suggesting disrupted segregation between sensory and cognitive processing. Moreover, FG scores within limbic and default mode networks were significantly correlated (, p < .005 after Bonferroni correction for both) with the symbol digit modality test (SDMT) score, a measure of information processing speed commonly used in MS neuropsychological assessments. Finally, leveraging supervised machine learning, we tested the predictive value of network‐level FG features, highlighting the prominent role of the FG scores within the default mode network in the accurate prediction of SDMT scores in MS patients (average mean absolute error of 1.22 ± 0.07 points on a hold‐out set of 24 patients). Our work provides a comprehensive evaluation of FG alterations in MS, shedding light on the hierarchical organization of the MS brain and suggesting that FG connectivity analysis can be regarded as a valuable approach in rs‐fMRI studies across different MS populations.

Cancer-related cognitive impairment and wellbeing in patients with newly diagnosed aggressive lymphoma compared to population norms and healthy controls: an exploratory study

PurposeThere has been little dedicated research on cancer-related cognitive impairment in patients with aggressive lymphoma. We describe and compare patients’ cognitive function with that of healthy controls and patients’ wellbeing and distress with general population values. We also explore associations between patients’ neuropsychological test performance and self-reported cognitive function and distress.MethodsSecondary analysis of data from a feasibility study of 30 patients with newly diagnosed aggressive lymphoma and 72 healthy controls. Patients completed neuropsychological tests and self-report measures before and 6–8 weeks after chemotherapy. Healthy controls completed neuropsychological tests and the FACT-Cog at enrolment and 6 months later. Mixed models were used to analyze neuropsychological test and FACT-Cog scores. One-sample t-tests were used to compare patients’ self-reported wellbeing and distress with population norms. Associations were explored with Kendall’s Tau b.ResultsPatients and healthy controls were well matched on socio-demographics. Differences between neuropsychological test scores were mostly large-sized; on average, patients’ scores on measures of information processing speed, executive function, and learning and memory were worse both before and after chemotherapy (all p ≤ 0.003). The same pattern was observed for impact of perceived cognitive impairment on quality-of-life (both p < 0.001). Patients’ physical and emotional wellbeing scores were lower than population norms both before and after chemotherapy (all p ≤ 0.018). Associations between neuropsychological performance and other measures were mostly trivial (all p > 0.10).ConclusionFor many patients with aggressive lymphoma, impaired neuropsychological test performance and impact of perceived impairments on quality-of-life precede chemotherapy and are sustained after chemotherapy. Findings support the need for large-scale longitudinal studies with this population to better understand targets for interventions to address cognitive impairments.

Cognitive rehabilitation program in patients with multiple sclerosis: A pilot study

IntroductionIn recent years, there has been an increase of studies dedicated to cognitive rehabilitation in patients with multiple sclerosis (MS); however, few of these analyze the impact on such variables as cognitive reserve. The study aims to explore the effects of a cognitive rehabilitation program comprising a combination of cognitive and physical exercises, as well as group sessions to improve cognitive performance, emotional state, and cognitive reserve index. MethodFifty patients with MS were subdivided into 2 groups: the control group, which performed aerobic exercise (n=25), and the experimental group (n=25), which participated in the integrated cognitive rehabilitation program (ICRP). All participants were evaluated 3 times (baseline, post-treatment, and long-term) with the Brief Repeatable Battery of Neuropsychological Tests, Cognitive Reserve Scale, Beck Depression Inventory, and a scale evaluating trait and state anxiety. ResultsCompared with the control group, patients in the experimental group showed improvements in cognitive function, with significant changes in measures of information processing speed, attention, memory, cognitive reserve index, and long-term mood. ConclusionsThe ICRP was effective in improving cognitive and emotional function in MS, and increased the cognitive reserve index.

Prodromal Cognitive Changes as a Prognostic Indicator of Forthcoming Huntington's Disease Severity: A Retrospective Longitudinal Study.

Cognitive changes in Huntington's disease (HD) precede motor manifestations. ENROLL-HD platform includes four cognitive measures of information processing speed (IPS). Our group is eager to seek clinical markers in the life stage that is as close as possible to the age of onset (ie, the so called prodromal HD phase) because this is the best time for therapeutic interventions. Our study aimed to test whether cognitive scores in prodromal ENROLL-HD mutation carriers show the potential to predict the severity of motor and behavioral changes once HD became fully manifested. From the global ENROLL-HD cohort of 21,343 participants, we first selected a premanifest Cohort#1 (ie, subjects with Total Motor Score (TMS) <10 and Diagnostic Confidence Level (DCL) <4, N = 1.222). From this cohort, we then focused on a prodromal Cohort#2 of subjects who were ascertained to phenoconvert into manifest HD at follow-up visits (ie, subjects from 6 ≤ TMS≤9 and DCL <4 to TMS≥10 and DCL = 4, n = 206). The main results of our study showed that low IPS before phenoconversion in Cohort#2 predicted the severity of motor and behavioral manifestations. By combining the four IPS cognitive measures (eg, the Categorical Verbal Fluency Test; Stroop Color Naming Test; Stroop Word Reading; Symbol Digit Modalities Test), we generated a Composite Cognition Score (CCS). The lower the CCS score the higher the TMS and the apathy scores in the same longitudinally followed-up patients after phenoconversion. CCS might represent a clinical instrument to predict the prognosis of mutation carriers who are close to manifesting HD.

Investigating the link between regional oxygen metabolism and cognitive speed in multiple sclerosis: Implications for fatigue

BackgroundMost multiple sclerosis (MS) patients experience fatigue and cognitive decline but the underlying mechanisms remain unknown. Previous work has shown whole brain resting cerebral metabolic rate of oxygen (CMRO2) is associated with the extent of these symptoms. However, it is not known if the association between global CMRO2 and MS-related cognitive speed and fatigue can be localized to specific brain regions. Based upon previous research suggesting prefrontal involvement in MS-related changes in cognitive speed and fatigue, we hypothesized that oxygen metabolic changes within prefrontal cortex (PFC) might form the pathophysiologic basis of cognitive performance and fatigue in MS patients. ObjectiveInvestigate whether PFC ΔCMRO2 is associated with cognitive speed and fatigue in MS. MethodsMS and healthy control (HC) participants were scanned using a dual-­echo fMRI sequence and underwent a hypercapnia calibration experiment that permitted estimation of ΔCMRO2 while performing a scanner version of symbol-digit modalities task, a measure of information processing speed and utilized in the clinic as a reliable sentinel biomarker for global cognitive impairment in MS. Participants then completed the Modified Fatigue Impact Scale (MFIS) to measure fatigue. ResultsMS patients exhibited significant reductions in cognitive performance relative to HCs (p < 0.04). Prefrontal ΔCMRO2 explained significant variability (ΔR2 = 0.11) in cognitive speed, over and above disease and demographic variables, for the MS group only. Prefrontal ΔCMRO2 was not associated with fatigue across groups. ΔCMRO2 in visual and motor areas were not associated with cognitive performance or fatigue for either group. ConclusionPrefrontal oxygen metabolism may be a sensitive measure of MS-related cognitive decline.

Associations of prenatal exposure to per- and polyfluoroalkyl substances (PFAS) with measures of cognition in 7.5-month-old infants: An exploratory study

BackgroundPrenatal exposure to per- and polyfluoroalkyl substances (PFAS) has been linked to a wide array of adverse maternal and child health outcomes. However, studies examining PFAS in relation to offspring cognition have been inconclusive. ObjectiveWe examined whether prenatal exposure to a mixture of PFAS was related to cognition in 7.5-month-old infants. MethodsOur analytic sample included participants enrolled in the Chemicals in Our Bodies (CIOB) and Illinois Kids Development Study (IKIDS) cohorts (N = 163). Seven PFAS were measured in 2nd trimester maternal serum samples and were detected in >65% of participants. Infant cognition was measured with a visual recognition memory task using an infrared eye tracker when infants were 7.5 months old. This task included familiarization trials where each infant was shown two identical faces and test trials where each infant was shown the familiar face paired with a novel face. In familiarization, we assessed average run duration (time looking at familiarization stimuli before looking away) as a measure of information processing speed, in addition to time to familiarization (time to reach 20 s of looking at stimuli) and shift rate (the number of times infants looked between stimuli), both as measures of attention. In test trials, we assessed novelty preference (proportion of time looking to the novel face) to measure recognition memory. Linear regression was used to estimate associations of individual PFAS with cognitive outcomes, while Bayesian kernel machine regression (BKMR) was used to estimate mixture effects. ResultsIn adjusted single-PFAS linear regression models, an interquartile range increase in PFNA, PFOA, PFOS, PFHxS, PFDeA, and PFUdA was associated with an increase in shift rate, reflecting better visual attention. Using BKMR, increasing quartiles of the PFAS mixture was similarly associated with a modest increase in shift rate. There were no significant associations between PFAS exposure and time to reach familiarization (another measure of attention), average run duration (information processing speed), or novelty preference (visual recognition memory). ConclusionIn our study population, prenatal PFAS exposure was modestly associated with an increase in shift rate and was not strongly associated with any adverse cognitive outcomes in 7.5-month-old infants.

Psychomotor Side Effects of Carbamazepine in an Elderly Patient With Bipolar Disorder and Cognitive Impairment

AbstractIntroductionThe management of elderly bipolar patients can become very complex due to higher prevalence of medical comorbidities and sensitivity to treatment-related adverse effects. One of the antiepileptic drugs used for their treatment, carbamazepine, has had a number of cognitive and psychomotor effects linked to it: deterioration in measures of information processing speed, and attention and faster motor skills after discontinuation, among others. The literature concerning them is quite sparse.MethodologyWe report the case of a 75-year-old woman with bipolar disorder and unspecified cognitive impairment who was brought to the emergency department by her family due to global functional decline dating 3 weeks back.ResultsThe patient had been diagnosed and in treatment with bipolar disorder for 40 years. About 2 months before the current episode, because of the presence of tremor and family reports of marked functional decline (from being independent for daily life activities to being bound to a wheelchair and with worsening cognitive symptoms), the psychiatrist opted for a gradual switch from valproate to carbamazepine. During our interview, her husband pointed to the complete dose of 100 mg of carbamazepine 3 weeks ago as the onset of her current symptoms. The patient demonstrated clear psychomotor inhibition, with an absence of spontaneous movement and sporadic, almost monosyllabic, responses to only the simplest questions. Although aware that she was in a hospital, she could not recall its name and was completely disoriented in regards to time. Barely capable of emoting with her facial muscles, she denied feeling depressed and only acknowledged a stomachache. After spending the night in observation, and the suspension of carbamazepine, the patient experienced an improvement of her cognitive functions: although still not fully oriented in space and time, she could now speak in sentences and answer most of our questions. Even though she still maintained not being depressed, when pressed about any weird sensations she admitted to the feeling of being dead inside. The decision was made to transfer her to the psychogeriatric hospitalization unit.DiscussionThe initial assessment of the patient was complicated due to a variety of factors. Beyond the physical comorbidities, the psychomotor inhibition impeded a thorough examination of her emotional state. Only the suppression of her evening dose of carbamazepine allowed for the diagnosis of Cotard-like major depressive symptoms. Even though the cognitive impairment was apparent before, the state of the patient was markedly improved with just the removal of carbamazepine and was confirmed by her family to be a lot closer to her base state of more than a month ago.ConclusionThe use of anticonvulsant therapy in elderly bipolar patients with cognitive impairment can have important side effects. Further evidence of the prevalence and specific nature and frequency of its side effects is needed.FundingNo Funding

Cognitive functions and symptoms predicting later use of psychiatric services following mild traumatic brain injury in school-age

ABSTRACT Objective To investigate whether neuropsychological test performance or presence of some specific injury symptoms at 1–3 months following pediatric mild traumatic brain injury (mTBI) can help to identify the children at risk for developing post-traumatic psychiatric symptoms. Methods Data from 120 children and adolescents aged 7–15 years, treated at Turku University Hospital between 2010 and 2016 due to mTBI, and who had undergone neuropsychological evaluation at 1–3 months following injury, were enrolled from the hospital records. Neuropsychological test performancesand injury symptom reports were retrospectively retrieved from the patient files. Results Slow information processing speed (p = 0.044), emotion regulation deficit (p = 0.014), impulsivity (p = 0.013), verbal processing difficulties (p = 0.042) and headache (p = 0.026) were independent predictors for having later contact in psychiatric care. Conclusions Neuropsychological examination containing measure of information processing speed, injury symptom interview, and parental questionnaires on behavioural issues of the child at 1–3 months following mTBI seems to be useful in detecting children with risk for post traumatic psychiatric symptoms. Targeted support and guidance for this group of children and adolescents and their families are recommended to prevent the development of an unfavorable psychosocial outcome.

Abstract 10087: Cognitive Evaluation During Pregnancy Among Women With Preeclampsia: A Pilot Feasibility Study

Introduction: Previous research has shown cognitive decline related to preeclampsia (preE) in women after pregnancy when using neurocognitive assessments; however, it is not known if changes in cognition occur antenatally (e.g., in the third trimester of pregnancy). This pilot study investigated if the cerebrovascular effect of preE can manifest as cognitive decline antenatally. Hypothesis: Pregnant preE women will score lower on cognitive tests in the executive and memory function domains compared with pregnant normotensive women. Methods: This was a prospective observational study in a single institution. We included women more than 28 weeks of gestation with preE or normotension. We excluded women with chronic hypertension, neurologic and developmental disabilities, and current substance use. Neurocognitive test battery included subjective (Everyday Cognition) and objective assessment of executive function (Stroop test, Trail Making), attention and working memory (Digit Span Subtest), and information processing speed (Digit Symbol Substitution) evaluated as z-scores. Baseline characteristics (e.g. pre-pregnancy Body mass index [BMI]) characteristics were collected. Results: We enrolled 1 to 2 women weekly over 4 months. Thirty pregnant women were included (16 preE; 14 normotensive). Those with preE had higher pre-pregnancy BMI, delivered at earlier gestational age and reported higher history of migraines. PreE vs. normotensive women had more memory complaints (p&lt;0.001) and scored lower on objective measures of information processing speed, attention, and the executive function of inhibition ( Table ). Conclusions: Assessment of cognition in pregnant preE and normotensive women is feasible. PreE women reported worse subjective memory, and had lower scores in attention, information processing speed, and the executive function. Future work to determine if these cognitive differences persist postpartum is warranted.

Personality factors and cognitive functioning in patients with somatic symptom and related disorders

ObjectiveSomatic symptom and related disorders (SSRD) are often complicated by cognitive symptoms, including reduced information processing speed, memory, and planning. Depression has been related to poor cognitive functioning in SSRD, but the role of underlying personality factors is poorly understood. This study investigates the association between personality factors (neuroticism, extraversion, openness, agreeableness, and conscientiousness) with cognitive functioning in patients with SSRD. MethodsData from 366 patients with SSRD from a tertiary care expert center (mean age = 42.1 years (SD = 13.4), 59.6% women) were analyzed using a cross-sectional design. Neuropsychological assessments included measures of information processing speed, memory, attention, and executive function. Personality factors were assessed using the NEO-FFI and depressive symptoms using the PHQ-9. ResultsRegression analyses showed associations between neuroticism with poorer performance on visual memory (B = −0.09, SE = 0.04, β = −0.14, p = .019), and planning (B = −0.09. SE = 0.02, β = −0.23, p < .001). Extraversion was also inversely associated with visual memory (B = −0.13, SE = 0.05, β = −0.18, p = .011) and planning (B = −0.07, SE = 0.03, β = −0.17, p = .021) and openness was associated with better visual memory (B = 0.17, SE = 0.05, β = 0.19, p = .002). These associations were attenuated but remained significant after adjusting for depressive symptoms. ConclusionNeuroticism, extraversion, and low openness were associated with lower cognitive functioning (particularly planning and visual memory) in patients with SSRD, which remained significant after taking depressive symptoms into account.

Ex-Gaussian analysis of simple response time as a measure of information processing speed and the relationship with brain morphometry in multiple sclerosis

BackgroundThe polyfactorial nature of the widely used symbol digit modalities test (SDMT) introduces significant measurement challenges in characterizing information processing speed (IPS) deficits in multiple sclerosis (MS). Measures with high psychometric IPS-specificity and less contamination from other cognitive domains are necessary to fully understand IPS changes. ObjectiveInvestigate how three mathematical modeling ex-Gaussian parameter estimates (mu, sigma, tau) derived from a simple response time (RT) task (1) differentiate MS from healthy control participants and (2) correspond to structural brain changes, to evaluate a novel IPS measurement approach. MethodsPersons with and without MS completed a two-minute behavioral simple RT task, structural MRI and the MS functional composite. RT distributions were deconvolved into ex-Gaussian parameter estimates using mathematical modeling. Group differences and brain-behavior relationships were statistically evaluated. ResultsPersons with MS experienced a general pattern of slowing as evidenced by a shift in the Gaussian (mu) component of the distribution. This correlated with whole brain volume and white matter specifically. Additionally, persons with MS had larger values of tau (elongated positively skewed tail) that may reflect attentional lapses. ConclusionThe ex-Gaussian approach is sensitive to disease-related IPS changes and provides nuanced information about IPS slowing in MS.

Association of low-frequency and rare coding variants with information processing speed

Measures of information processing speed vary between individuals and decline with age. Studies of aging twins suggest heritability may be as high as 67%. The Illumina HumanExome Bead Chip genotyping array was used to examine the association of rare coding variants with performance on the Digit-Symbol Substitution Test (DSST) in community-dwelling adults participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. DSST scores were available for 30,576 individuals of European ancestry from nine cohorts and for 5758 individuals of African ancestry from four cohorts who were older than 45 years and free of dementia and clinical stroke. Linear regression models adjusted for age and gender were used for analysis of single genetic variants, and the T5, T1, and T01 burden tests that aggregate the number of rare alleles by gene were also applied. Secondary analyses included further adjustment for education. Meta-analyses to combine cohort-specific results were carried out separately for each ancestry group. Variants in RNF19A reached the threshold for statistical significance (p = 2.01 × 10−6) using the T01 test in individuals of European descent. RNF19A belongs to the class of E3 ubiquitin ligases that confer substrate specificity when proteins are ubiquitinated and targeted for degradation through the 26S proteasome. Variants in SLC22A7 and OR51A7 were suggestively associated with DSST scores after adjustment for education for African-American participants and in the European cohorts, respectively. Further functional characterization of its substrates will be required to confirm the role of RNF19A in cognitive function.

Cognitive rehabilitation program in patients with multiple sclerosis: A pilot study

IntroductionIn recent years, there has been an increase of studies dedicated to cognitive rehabilitation in patients with multiple sclerosis (MS); however, few of these analyze the impact on such variables as cognitive reserve. The study aims to explore the effects of a cognitive rehabilitation program comprising a combination of cognitive and physical exercises, as well as group sessions to improve cognitive performance, emotional state, and cognitive reserve index. MethodFifty patients with MS were subdivided into 2 groups: the control group, which performed aerobic exercise (n=25), and the experimental group (n=25), which participated in the integrated cognitive rehabilitation program (ICRP). All participants were evaluated 3 times (baseline, post-treatment, and long-term) with the Brief Repeatable Battery of Neuropsychological Tests, Cognitive Reserve Scale, Beck Depression Inventory, and a scale evaluating trait and state anxiety. ResultsCompared with the control group, patients in the experimental group showed improvements in cognitive function, with significant changes in measures of information processing speed, attention, memory, cognitive reserve index, and long-term mood. ConclusionsThe ICRP was effective in improving cognitive and emotional function in MS, and increased the cognitive reserve index.

Computerized Symbol Digit Modalities Test in a Swiss Pediatric Cohort - Part 2: Clinical Implementation.

BackgroundInformation processing speed (IPS) is a marker for cognitive function. It is associated with neural maturation and increases during development. Traditionally, IPS is measured using paper and pencil tasks requiring fine motor skills. Such skills are often impaired in patients with neurological conditions. Therefore, an alternative that does not need motor dexterity is desirable. One option is the computerized symbol digit modalities test (c-SDMT), which requires the patient to verbally associate numbers with symbols.MethodsEighty-six participants (8–16 years old; 45 male; 48 inpatients) were examined, 38 healthy and 48 hospitalized for a non-neurological disease. All participants performed the written SDMT, c-SDMT, and the Test of Non-verbal Intelligence Fourth Edition (TONI-4). Statistical analyses included a multivariate analysis of covariance (MANCOVA) for the effects of intelligence (IQ) and hospitalization on the performance of the SDMT and c-SDMT. A repeated measures analysis of variance (repeated measures ANOVA) was used to compare performance across c-SDMT trials between inpatients and outpatients.ResultsThe MANCOVA showed that hospitalization had a significant effect on IPS when measured with the SDMT (p = 0.04) but not with the c-SDMT (p = 0.68), while IQ (p = 0.92) had no effect on IPS. Age (p < 0.001) was the best predictor of performance of both tests. The repeated measures ANOVA revealed no significant difference in within-test performance (p = 0.06) between outpatient and inpatient participants in the c-SDMT.ConclusionPerformance of the c-SDMT is not confounded by hospitalization and gives within-test information. As a valid and reliable measure of IPS for children and adolescents, it is suitable for use in both inpatient and outpatient populations.

The Symbol Digit Modalities Test (SDMT) is sensitive but non-specific in MS: Lexical access speed, memory, and information processing speed independently contribute to SDMT performance

BackgroundThe Symbol Digit Modalities Test (SDMT) is the most sensitive metric of neurocognitive function in multiple sclerosis (MS), and is consistently interpreted as a measure of information processing speed (IPS). ObjectiveTo evaluate the cognitive psychometric profile captured by the SDMT to identify whether different cognitive processes independently underlie performance. MethodsThree samples of MS patients (total n=661; 185 research patients at MS center; 370 clinical patients at MS center; 106 persons with MS from the community) completed objective assessments of neuropsychological function across cognitive domains. Exploratory factor analysis (EFA) was used to derive latent cognitive factor scores, and operationalize cognitive domain composite scores, to understand the unique, shared and redundant contribution of different cognitive domains to SDMT performance using hierarchical multiple regression and commonality analysis. ResultsAcross three independent samples we provide converging strong evidence that the cognitive domains of Memory, IPS and Rapid Automatized Naming (lexical access speed) jointly and uniquely contribute to SDMT performance. ConclusionThe SDMT measures multiple cognitive processes, which likely explains the high degree of sensitivity to cognitive change in MS. Researchers and clinicians should interpret the SDMT as a multifarious measure of general cognition rather than a specific test of IPS.

Cognitive complaint and objective cognition during the post-acute period after mild traumatic brain injury in pre-morbidly healthy adults

ABSTRACT Primary Objective: The most widely used proxies of cognitive complaint after mTBI are post-concussion syndrome (PCS) symptom checklists, which do not have a clear relationship with cognition. This study investigated whether an mTBI-specific cognitive complaint measure would have clearer associations with objective cognition than a widely used PCS symptom checklist. Research Design: An observational design was used. A sample of 109 participants (52 mTBI and 57 healthy controls) completed a PCS symptom checklist, a cognitive complaint measure, and measures of information processing speed, attention, memory, executive function, depression and anxiety. Main Outcomes and Results: In the healthy control group, cognitive complaint was significantly associated with objective cognitive performance and was not associated with psychological status. In contrast, PCS endorsement was unrelated to objective cognition but was associated with psychological status. For the mTBI group, neither PCS endorsement nor cognitive complaint was associated with cognitive performance, but both measures were associated with psychological status. Conclusions: This study indicates that neither cognitive nor PCS symptom measures are reliable indicators of underlying cognitive function in the post-acute period after mTBI. Further, suffering an mTBI may affect the linear relationship that exists between cognitive symptom endorsement and cognitive function in healthy adults.

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.

Hemoglobin A1c and 10-year information processing speed in Japanese community dwellers

BackgroundHyperglycemia is believed to be a risk factor for cognitive decline, but the longitudinal relationship between hyperglycemia and cognitive decline in the Japanese population is unclear. The present study aimed to clarify the association between blood glucose levels and information processing ability in middle-aged and older adults.MethodsThe subjects were 866 men and 815 women aged 40–79 years not taking medication for diabetes who participated in the first study wave (1997–2000) and then participated at least once in the subsequent six study waves (2000–2012) of the National Institute for Longevity Sciences—Longitudinal Study of Aging, Japan. Hemoglobin A1c (HbA1c) levels were categorized into four groups (< 5.6, 5.6 to < 6.0, 6.0 to < 6.5, ≥ 6.5%), and a mixed-effects model was used to evaluate the effects of the HbA1c level (four groups) on repeated measures of information processing speed. The models also included baseline age, body mass index, ethanol intake, smoking status, educational level, family income, and history of stroke, hypertension, heart disease, and dyslipidemia as covariates.ResultsMean (standard deviation) HbA1c and follow-up time in participants were 5.2 (0.5) % and 10.0 (3.6) years, respectively. A linear mixed model showed that the main effect of the four HbA1c groups on information processing ability was not significant in either men or women, but the interaction of HbA1c and time with information processing speed in the higher HbA1c level groups (≥ 6.5% group in men, 6.0 to < 6.5% and ≥ 6.5% groups in women) was significant compared to the lower HbA1c level (< 5.6%) group (P < 0.05). When the slope of information processing speed by HbA1c level at baseline was examined, the slope of information processing speed in the higher HbA1c level (≥ 6.5%) group was higher than in the lower HbA1c level (< 5.6%) group, both in men (− 0.31/year) and in women (− 0.30/year), as well as in women with an HbA1c level of 6.0 to < 6.5% (− 0.40/year).ConclusionsHigher baseline HbA1c was associated with greater subsequent decline in information processing ability in Japanese community dwellers, even with the pre-clinical HbA1c level (6.0 to < 6.5%) in women. The results suggest that good glycemic control or prevention of hyperglycemia may contribute to maintaining information processing ability.

Patterns of cognitive deficits in persons with spinal cord injury as compared with both age-matched and older individuals without spinal cord injury

Context/Objective: Cognitive deficits can impact as many as 60% of individuals with spinal cord injury (SCI). In an effort to identify the nature of cognitive deficits in SCI, we examined neuropsychological test performance in individuals with SCI, age matched healthy controls and older healthy controls.Design: Participants completed a motor-free neuropsychological test battery assessing attention, working memory, information processing speed, new learning /memory and executive control.Setting: Outpatient rehabilitation research facility.Participants: Participants included 60 individuals with chronic spinal cord injury [SCI; 32 with paraplegia (T2-T12) and 28 with tetraplegia (C3-T1)], 30 age-matched healthy controls (AMHC; 30–40 years old) and 20 older healthy controls (OHC; 50–60 years old).Outcome Measures: Wechsler Intelligence Scale – 3rd edition (WAIS-III) Digit Span and Letter-Number Sequencing; Symbol Digit Modalities Test (SDMT) – oral version; California Verbal Learning Test-II; Paced Auditory Serial Addition Test (PASAT); Wechsler Abbreviated Scale of Intelligence (WASI); Delis-Kaplan Executive Function System; Verbal Fluency subtest.Results: Significant differences were noted between the SCI and AMHC groups on measures of information processing speed, new learning and memory, and verbal fluency. No significant differences were noted between the groups on tests of attention or working memory.Conclusion: The current study documented differences in specific realms of cognitive functioning between a chronic SCI sample and AMHC. Implications for cognitive rehabilitation and overall quality of life are discussed. Additional research is needed utilizing a more comprehensive battery of motor-free neuropsychological tests that avoid the confound of upper limb motor limitations on cognitive performance.

Role of positive lifestyle activities on mood, cognition, well-being, and disease characteristics in multiple sclerosis

ABSTRACTMultiple sclerosis (MS) is a neurological condition associated with a wide variety of physical, cognitive, and mood-related symptoms. While disease-modifying treatment has been shown to reduce the severity and frequency of MS symptom relapses, engagement in certain daily activities holds promise as an adjunctive treatment to better manage disease sequelae. The present study sought to determine whether healthy nutritional choices, exercise, and social/intellectual engagement impacts functioning in individuals with MS. Two hundred and forty-eight (248) MS participants completed a questionnaire assessing factors related to cognitive health (Cognitive Health Questionnaire; CHQ). They also endorsed measures assessing disease symptoms and management, mood, and well-being/quality of life. A measure of information processing speed was administered to a subset of participants. Findings indicated that a previously derived CHQ factor comprised of healthy nutritional habits and exercise items was associated with less fatigue, better sleep, reduced pain, and improved mood and disease management. A factor with items assessing social and intellectual engagement correlated with mood, disease management, and well-being. Endorsement of items in both CHQ factors was associated with better information processing speed. Subsequent regression analyses indicated that education and mood were most predictive of nutritional habits and exercise, while MS self-efficacy was particularly associated with engagement in social and intellectual activities. In sum, these findings suggest that self-reported engagement in healthy lifestyle habits has far-reaching effects on multiple aspects of daily living and disease management in MS.