Dual Task of Fine Motor Skill and Problem Solving in Individuals With Multiple Sclerosis: A Pilot Study

OBJECTIVES

To (1) examine and compare dual-task performance in patients with multiple sclerosis (MS) and healthy controls (HCs) using mathematical problem-solving questions that included an everyday competence component while performing an upper extremity fine motor task; and (2) examine whether difficulties in dual-task performance are associated with problems in performing an everyday internet task.

DESIGN

Pilot study, mixed-design with both a within and between subjects' factor.

SETTING

A nonprofit rehabilitation research institution and the community.

PARTICIPANTS

Participants (N=38) included persons with MS (n=19) and HCs (n=19) who were recruited from a nonprofit rehabilitation research institution and from the community.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Participant were presented with 2 testing conditions: (1) solving mathematical everyday problems or placing bolts into divots (single-task condition); and (2) solving problems while putting bolts into divots (dual-task condition). Additionally, participants were required to perform a test of everyday internet competence.

RESULTS

As expected, dual-task performance was significantly worse than either of the single-task tasks (ie, number of bolts into divots or correct answers, and time to answer the questions). Cognitive but not motor dual-task cost was associated with worse performance in activities of everyday internet tasks.

CONCLUSIONS

Cognitive dual-task cost is significantly associated with worse performance of everyday technology. This was not observed in the motor dual-task cost. The implications of dual-task costs on everyday activity are discussed.

Cognitive fatigue in individuals with traumatic brain injury is associated with caudate activation

We investigated differences in brain activation associated with cognitive fatigue between persons with traumatic brain injury (TBI) and healthy controls (HCs). Twenty-two participants with moderate-severe TBI and 20 HCs performed four blocks of a difficult working memory task and four blocks of a control task during fMRI imaging. Cognitive fatigue, assessed before and after each block, was used as a covariate to assess fatigue-related brain activation. The TBI group reported more fatigue than the HCs, though their performance was comparable. Regarding brain activation, the TBI group showed a Task X Fatigue interaction in the caudate tail resulting from a positive correlation between fatigue and brain activation for the difficult task and a negative relationship for the control task. The HC group showed the same Task X Fatigue interaction in the caudate head. Because we had prior hypotheses about the caudate, we performed a confirmatory analysis of a separate dataset in which the same subjects performed a processing speed task. A relationship between Fatigue and brain activation was evident in the caudate for this task as well. These results underscore the importance of the caudate nucleus in relation to cognitive fatigue.

The MSOAC approach to developing performance outcomes to measure and monitor multiple sclerosis disability

Background:

The Multiple Sclerosis Outcome Assessments Consortium (MSOAC) was formed by the National MS Society to develop improved measures of multiple sclerosis (MS)-related disability.

Objectives:

(1) To assess the current literature and available data on functional performance outcome measures (PerfOs) and (2) to determine suitability of using PerfOs to quantify MS disability in MS clinical trials.

Methods:

(1) Identify disability dimensions common in MS; (2) conduct a comprehensive literature review of measures for those dimensions; (3) develop an MS Clinical Data Interchange Standards Consortium (CDISC) data standard; (4) create a database of standardized, pooled clinical trial data; (5) analyze the pooled data to assess psychometric properties of candidate measures; and (6) work with regulatory agencies to use the measures as primary or secondary outcomes in MS clinical trials.

Conclusion:

Considerable data exist supporting measures of the functional domains ambulation, manual dexterity, vision, and cognition. A CDISC standard for MS (http://www.cdisc.org/therapeutic#MS) was published, allowing pooling of clinical trial data. MSOAC member organizations contributed clinical data from 16 trials, including 14,370 subjects. Data from placebo-arm subjects are available to qualified researchers. This integrated, standardized dataset is being analyzed to support qualification of disability endpoints by regulatory agencies.

Older and Happier? Associations Among Age, Affective Symptomatology, and Quality of Life in Persons With Multiple Sclerosis

Date Presented 3/31/2017

This study identifies a relationship between age and quality of life in persons with multiple sclerosis. It highlights the role of promoting coping in younger adults to prevent or decrease symptoms of depression or anxiety as a means of increasing quality of life.

Primary Author and Speaker: Brocha Stern

Contributing Authors: John DeLuca, Yael Goverover

Fronto-striatal network activation leads to less fatigue in multiple sclerosis

BACKGROUND

The fronto-striatal network has been implicated in both fatigue, a common multiple sclerosis (MS) symptom, and goal attainment, which has been shown to reduce fatigue in healthy individuals.

OBJECTIVES

To investigate whether stimulation of the fronto-striatal network through goal attainment (potential monetary gain) leads to fatigue reduction in MS and healthy control (HC) participants.

METHODS

In all, 14 healthy and 19 MS participants performed a gambling task during functional magnetic resonance imaging (fMRI). Participants were presented with an opportunity to receive monetary reward during the outcome condition of the task but not during the no outcome condition. Self-reported fatigue measures were obtained after each condition and outside of the scanner. Structural alterations were also examined.

RESULTS

A significant decrease in fatigue was observed after the outcome condition compared to the no outcome condition in both groups. Significantly greater activation was observed in the ventral striatum in association with the outcome condition compared to the no outcome condition in both groups. Ventromedial prefrontal cortex showed significantly greater activation during the no outcome condition compared to the outcome condition with greater difference between conditions in the HC group.

CONCLUSION

This is the first functional neuroimaging study showing that stimulation of the fronto-striatal network through goal attainment leads to decreased on-task fatigue in MS and healthy participants.

A randomized controlled trial to treat impaired learning and memory in multiple sclerosis: The self-GEN trial

Background:

Difficulties in learning and memory are among the most persistent and frequently reported cognitive symptoms in individuals with multiple sclerosis (MS).

Objective:

To examine the efficacy of the self-generation learning program ( self-GEN trial) that consist of behavioral intervention sessions, teaching self-generation technique while using metacognitive strategies to improve learning and memory abilities in persons with MS. Additionally, the treatment aimed to address generalization of the treatment to activities of daily living.

Methods:

This double-blind, placebo-controlled, randomized clinical trial included 35 participants with clinically definite MS, 19 in the treatment group and 16 in the placebo control group. Participants completed a baseline neuropsychological assessment, including questionnaires assessing everyday memory and a repeat assessment immediately post-treatment.

Results:

The treatment group showed significantly improved learning and memory, self-regulation, and metacognition relative to the placebo post-treatment. Similar results were noted on measures of depression, functional status, and quality of life (QOL).

Conclusion:

This study provides initial Class I evidence that the self-GEN behavioral intervention improves memory, self-regulation, functional status, affective symptomatology, and QOL in patients with MS.

Altered neural mechanisms of cognitive control in patients with primary progressive multiple sclerosis: An effective connectivity study

Primary progressive multiple sclerosis (PPMS) leads to physical and cognitive disability. Specifically, cognitive deficits in PPMS have been explained by both grey matter atrophy and white matter lesions. However, existing research still lacks in the understanding of how the brain of a patient with PPMS functions under cognitive control demands. Thus, the aim of the current study was to examine information integration in patients with PPMS using a search-based effective connectivity method. Fourteen patients with PPMS and 22 age- and gender-matched healthy controls (HC) performed the Stroop task, a cognitively demanding interference task that taxes neural resources required for cognitive control and response inhibition. Results showed that compared to HC, PPMS patients exhibited poor behavioral performance and alterations in information flow, manifested in the form of the loss of top-down connections, reversal of connections, and hyperconnectivity. Significant correlations were observed between connection strengths and behavioral measures. The connection between the posterior parietal cortex (PCC) and left posterior parietal lobule, which was present in both groups, showed a negative correlation with performance accuracy on incongruent trials. The connection between the left dorsolateral prefrontal cortex and PCC showed a positive correlation with performance accuracy on incongruent trials. However, the adaptive nature of this connection was not significant on a behavioral level as the PPMS group performed significantly worse compared to the HC group during the Stroop task. Thus, the current study provides important evidence about effective connectivity patterns that can be characterized as maladaptive cerebral re-organization in the PPMS brain. Hum Brain Mapp 38:2580-2588, 2017. © 2017 Wiley Periodicals, Inc.

Validity of the Symbol Digit Modalities Test as a cognition performance outcome measure for multiple sclerosis

Cognitive and motor performance measures are commonly employed in multiple sclerosis (MS) research, particularly when the purpose is to determine the efficacy of treatment. The increasing focus of new therapies on slowing progression or reversing neurological disability makes the utilization of sensitive, reproducible, and valid measures essential. Processing speed is a basic elemental cognitive function that likely influences downstream processes such as memory. The Multiple Sclerosis Outcome Assessments Consortium (MSOAC) includes representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with MS. Among the MSOAC goals is acceptance and qualification by regulators of performance outcomes that are highly reliable and valid, practical, cost-effective, and meaningful to persons with MS. A critical step for these neuroperformance metrics is elucidation of clinically relevant benchmarks, well-defined degrees of disability, and gradients of change that are deemed clinically meaningful. This topical review provides an overview of research on one particular cognitive measure, the Symbol Digit Modalities Test (SDMT), recognized as being particularly sensitive to slowed processing of information that is commonly seen in MS. The research in MS clearly supports the reliability and validity of this test and recently has supported a responder definition of SDMT change approximating 4 points or 10% in magnitude.

Retention in buprenorphine treatment is associated with improved HCV care outcomes

Persons who inject drugs, most of whom are opioid dependent, comprise the majority of the HCV infected in the United States. As the national opioid epidemic unfolds, increasing numbers of people are entering the medical system to access treatment for opioid use disorder, specifically with buprenorphine. Yet little is known about HCV care in patients accessing buprenorphine-based opioid treatment. We sought to determine the HCV prevalence, cascade of care, and the association between patient characteristics and completion of HCV cascade of care milestones for patients initiating buprenorphine treatment. We reviewed electronic health records of all patients who initiated buprenorphine treatment at a primary-care clinic in the Bronx, NY between January 2009 and January 2014. Of the 390 patients who initiated buprenorphine treatment, 123 were confirmed to have chronic HCV infection. The only patient characteristic associated with achieving HCV care milestones was retention in opioid treatment. Patients retained (vs. not retained) in buprenorphine treatment were more likely to be referred for HCV specialty care (63.1% vs. 34.0%, p<0.01), achieve an HCV-specific evaluation (40.8% vs. 21.3%, p<0.05), be offered HCV treatment (22.4% vs. 8.5%, p<0.05), and initiate HCV treatment (9.2% vs. 6.4%, p=0.6). Given the current opioid epidemic in the US and the growing number of people receiving buprenorphine treatment, there is an unprecedented opportunity to access and treat persons with HCV, reducing HCV transmission, morbidity and mortality. Retention in opioid treatment may improve linkage and retention in HCV care; innovative models of care that integrate opioid drug treatment with HCV treatment are essential.

Systematically developed pilot randomized controlled trial of exercise and cognition in persons with multiple sclerosis

Cognitive impairment is common and debilitating among persons with multiple sclerosis (MS) and might be managed with exercise training. The present pilot study adopted a single-blind randomized controlled trial (RCT) design and is the first to examine the effect of a systematically developed, progressive treadmill walking exercise training intervention on cognition among fully ambulatory persons with MS. Ten fully ambulatory females with MS were randomly assigned into exercise training intervention or waitlist control conditions. The intervention condition involved 12 weeks of supervised, progressive chronic treadmill walking exercise training. Participants underwent measures of cognition (i.e., cognitive processing speed (CPS), executive function), walking performance, and cardiorespiratory fitness before and after the 12-week period; baseline and follow-up assessments were performed by blinded assessors. Overall, there were large intervention effects on CPS (d = 0.95), walking performance (d = 0.76), and cardiorespiratory fitness (d > 1.08). The change in cardiorespiratory fitness was significantly associated with change in CPS (r = .60), but not walking performance. This small pilot RCT provides preliminary proof-of-concept data supporting progressive treadmill walking exercise training for potentially improving CPS, walking performance, and cardiorespiratory fitness in fully ambulatory persons with MS, and that improved fitness might be a possible mechanism for improved CPS.

The Perceived Deficits Questionnaire: Perception, Deficit, or Distress?

BACKGROUND

Cognitive dysfunction affects approximately 43% to 70% of individuals with multiple sclerosis (MS) and is an important determinant of several functional outcomes in MS and quality of life. Brief neuropsychological test batteries have been developed specifically for use in MS and are widely used to aid clinicians in assessing levels of cognitive impairment in MS. Neuropsychologists and neurologists also frequently use briefer screening measures, such as the Perceived Deficits Questionnaire (PDQ), to assist in determining whether a more extensive neuropsychological evaluation is warranted. However, despite the ease of such measures, the relationship between self-report and objective cognitive impairment has been inconsistent, at best. Moreover, factors such as depression, fatigue, anxiety, and personality have been found to be more related to reports of cognitive difficulties. The purpose of the present study was to clarify the relationship between subjective cognitive concerns and objective cognitive impairment while accounting for related symptoms.

METHODS

We examined the association of self-reported cognitive concerns on the PDQ with objective cognitive measures, as well as depression, anxiety, fatigue, and self-efficacy.

RESULTS

There was no relationship between self-reported cognitive concerns and objective performance. Rather, reports on the PDQ were more correlated with reports of depression, anxiety, fatigue, and self-efficacy.

CONCLUSIONS

Depression and poor self-efficacy can contribute to reports of cognitive difficulties. Effective treatment to improve these factors seems warranted given the impact of perceived cognitive impairment on outcomes in MS and the potential for more accurate self-reports.

Systematic, Evidence-Based Review of Exercise, Physical Activity, and Physical Fitness Effects on Cognition in Persons with Multiple Sclerosis

Cognitive dysfunction is highly prevalent, disabling, and poorly-managed in persons with multiple sclerosis (MS). Recent evidence suggests that exercise might have beneficial effects on cognition in this population. The current systematic, evidence-based review examined the existing literature on exercise, physical activity, and physical fitness effects on cognition in MS to accurately describe the current status of the field, offer recommendations for clinicians, and identify study-specific and participant-specific characteristics for providing future direction for ongoing MS research. We performed an open-dated search of Medline, PsychInfo, and CINAHL in December 2015. The search strategy involved using the terms 'exercise' OR 'physical activity' OR 'physical fitness' OR 'aerobic' OR 'resistance' OR 'balance' OR 'walking' OR 'yoga' OR 'training' OR 'rehabilitation' AND 'multiple sclerosis'. Articles were eliminated from the systematic review if it was a review article, theoretical paper, or textbook chapter; did not involve persons with MS; involved only persons with pediatric-onset MS; did not involve neuropsychological outcomes; did not include empirical data to evaluate outcomes; involved pharmacological interventions; or was not available in English. The selected articles were first classified as examining exercise, physical activity, or physical fitness, and were then randomly assigned to 2 independent reviewers who rated each article for level of evidence based on American Academy of Neurology criteria. Reviewers further completed a table to characterize important elements of each study (i.e., intervention characteristics), the cognitive domain(s) that were targeted, participant-specific characteristics, outcome measures, and study results. The present review resulted in 26 studies on the effects of exercise, physical activity, and physical fitness on cognition in persons with MS. This included 1 Class I study, 3 Class II studies, 8 Class III studies, and 14 Class IV studies. Of the 26 total studies, 6 were randomized controlled trials. Overall, there is conflicting evidence for the effects of exercise on cognition in MS, and overall positive, but not definitive evidence for the effects of physical activity and physical fitness, respectively, on cognition in this population. Collectively, there is insufficient well-designed research to definitively conclude that exercise, physical activity, and physical fitness are effective for improving cognition in MS. This is based, in part, on methodological issues of Class I and II studies, such as inclusion of cognition as a secondary outcome (35 % of reviewed studies), poorly-developed exercise interventions, and paucity of research that included cognitively-impaired MS samples. However, promising evidence from Class III and Class IV studies may be useful for informing the development of better intervention research.

Cognitive rehabilitation of working memory in juvenile multiple sclerosis-effects on cognitive functioning, functional MRI and network related connectivity

PURPOSE

To assess possible effects of working memory (WM) training on cognitive functionality, functional MRI and brain connectivity in patients with juvenile MS.

METHODS

Cognitive status, fMRI and inter-network connectivity were assessed in 5 cases with juvenile MS aged between 12 and 18 years. Afterwards they received a computerized WM training for four weeks. Primary cognitive outcome measures were WM (visual and verbal) and alertness. Activation patterns related to WM were assessed during fMRI using an N-Back task with increasing difficulty. Inter-network connectivity analyses were focused on fronto-parietal (left and right), default-mode (dorsal and ventral) and the anterior salience network. Cognitive functioning, fMRI and inter-network connectivity were reassessed directly after the training and again nine months following training.

RESULTS

Response to treatment was seen in two patients. These patients showed increased performance in WM and alertness after the training. These behavioural changes were accompanied by increased WM network activation and systematic changes in inter-network connectivity. The remaining participants were non-responders to treatment. Effects on cognitive performance were maintained up to nine months after training, whereas effects observed by fMRI disappeared.

CONCLUSIONS

Responders revealed training effects on all applied outcome measures. Disease activity and general intelligence may be factors associated with response to treatment.

A Phase Ib Study of BEZ235, a Dual Inhibitor of Phosphatidylinositol 3-Kinase (PI3K) and Mammalian Target of Rapamycin (mTOR), in Patients With Advanced Renal Cell Carcinoma

Lessons Learned

Our results highlight additional toxicities of dual PI3K/mTOR inhibition in the clinical setting that were unforeseen from preclinical models.

Because of toxicity and lack of efficacy, BEZ235 should not be further developed in the current formulation for patients with renal cell carcinoma.

Background.

Allosteric inhibitors of the mammalian target of rapamycin complex 1 (mTORC1) are approved for advanced renal cell carcinoma (RCC). Preclinical models have suggested that dual inhibition of phosphatidylinositol 3-kinase (PI3K) and mTOR kinase may establish superior anticancer effect. We aimed to establish safety for BEZ235, a potent inhibitor of both PI3K and mTOR, in advanced RCC.

Methods.

Patients with advanced RCC who had previously failed standard therapy received escalating doses of BEZ235 in sachet formulation twice daily until progression or unacceptable toxicity. Primary endpoints were to identify the maximally tolerated dose (MTD) and to determine the recommended dose for the phase II study.

Results.

The study was terminated early because of high incidence of dose-limiting toxicities (DLTs) across all dose levels tested. Ten patients were treated with BEZ235—six with clear cell and four with non-clear cell subtypes. Five of these patients suffered DLTs: 2 of 2 patients in the original 400 mg b.i.d. cohort, 1 of 6 in the 200 mg b.i.d. cohort, and 2 of 2 in the 300 mg b.i.d. cohort. DLTs included fatigue, rash, nausea and vomiting, diarrhea, mucositis, anorexia, and dysgeusia. Five patients were evaluable for response: Two had stable disease as best response, and three had progressive disease.

Conclusion.

BEZ235 twice daily resulted in significant toxicity without objective responses; further development of this compound will not be pursued in this disease.

Assessing the criterion validity of four highly abbreviated measures from the Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS)

OBJECTIVE

Cognitive dysfunction is prevalent in multiple sclerosis. As self-reported cognitive functioning is unreliable, brief objective screening measures are needed. Utilizing widely used full-length neuropsychological tests, this study aimed to establish the criterion validity of highly abbreviated versions of the Brief Visuospatial Memory Test - Revised (BVMT-R), Symbol Digit Modalities Test (SDMT), Delis-Kaplan Executive Function System (D-KEFS) Sorting Test, and Controlled Oral Word Association Test (COWAT) in order to begin developing an MS-specific screening battery.

METHOD

Participants from Holy Name Medical Center and the Kessler Foundation were administered one or more of these four measures. Using test-specific criterion to identify impairment at both -1.5 and -2.0 SD, receiver-operating-characteristic (ROC) analyses of BVMT-R Trial 1, Trial 2, and Trial 1 + 2 raw data (N = 286) were run to calculate the classification accuracy of the abbreviated version, as well as the sensitivity and specificity. The same methods were used for SDMT 30-s and 60-s (N = 321), D-KEFS Sorting Free Card Sort 1 (N = 120), and COWAT letters F and A (N = 298).

RESULTS

Using these definitions of impairment, each analysis yielded high classification accuracy (89.3 to 94.3%).

CONCLUSIONS

BVMT-R Trial 1, SDMT 30-s, D-KEFS Free Card Sort 1, and COWAT F possess good criterion validity in detecting impairment on their respective overall measure, capturing much of the same information as the full version. Along with the first two trials of the California Verbal Learning Test - Second Edition (CVLT-II), these five highly abbreviated measures may be used to develop a brief screening battery.

Money Management Activities in Persons With Multiple Sclerosis

OBJECTIVES

To examine whether participants with multiple sclerosis (MS) have more problems in managing finances compared with persons without MS, and to examine the variables that may contribute to these problems.

DESIGN

A cross-sectional study.

SETTING

Nonprofit rehabilitation research institution and the community.

PARTICIPANTS

Participants (N=53) comprised adults with MS (n=30) and persons without MS (n=23) who were recruited from a nonprofit rehabilitation research institution and from the community.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Participants were administered a battery of neuropsychological tests, a money management survey, and a functional test to assess money management skills.

RESULTS

Individuals with MS reported and demonstrated more problems managing money than persons without MS. Impaired cognitive functioning was significantly correlated with difficulties in money management. Self-report of functional status (Functional Behavior Profile) was significantly correlated with self-reported money management skills.

CONCLUSIONS

To our knowledge, this is the first study to examine money management in MS. Money management is an important activity of daily living that presents problems for individuals with MS. Managing one's own money requires adequate processing speed abilities as well as executive-attentional abilities. Additional studies are needed to explore this area and understand the nature of the problem.

Information processing speed in multiple sclerosis: Past, present, and future

BACKGROUND

Information processing speed (IPS) is a prevalent cognitive impairment in multiple sclerosis (MS).

OBJECTIVES

This review aims to summarize the methods applied to assess IPS in MS and its theoretical conceptualization. A PubMed search was performed to select articles published between 1 January 2004 and 31 December 2013, resulting in 157 articles included.

RESULTS

The majority (54%) of studies assessed IPS with heterogeneous samples (several disease courses). Studies often report controlling for presence of other neurological disorders (60.5%), age (58.6%), education (51.6%), alcohol history (47.8%), or use of steroids (39.5%). Potential confounding variables, such as recent relapses (50.3%), history of developmental disorders (19.1%), and visual problems (29.9%), were often neglected. Assessments used to study IPS were heterogeneous (ranging from simple to complex tasks) among the studies under review, with 62 different tasks used. Only 9.6% of articles defined the construct of IPS and 22.3% discussed IPS in relation to a theoretical model.

FUTURE DIRECTIONS

The challenges for the upcoming decade include clarification of the definition of IPS as well as its theoretical conceptualization and a consensus on assessment. Based on the results obtained, we propose a new theoretical model, the tri-factor model of IPS.

A pilot study of changes in functional brain activity during a working memory task after mSMT treatment: The MEMREHAB trial

BACKGROUND

Working memory deficits are common in multiple sclerosis (MS). The modified Story Memory Technique (mSMT) has been shown to improve new learning and memory in MS, but its effects on working memory (WM) are currently unknown.

OBJECTIVE

The present study presents a secondary analysis of data from a larger double-blind, placebo-controlled, randomized clinical trial and examines changes in cerebral activation on a WM task following mSMT treatment.

METHODS

Sixteen participants with clinically definite MS were randomly assigned to treatment (n=7) or placebo-control groups (n=9) matched for gender, age and education. Baseline and immediate follow-up functional Magnetic Resonance Imaging (fMRI) was obtained for all subjects. During fMRI participants completed an N-back task, consisting of 0-, 1-and 2-back conditions.

RESULTS

Significant increases in cerebral activation were noted in the dorsolateral prefrontal cortex, supplementary motor area and inferior parietal lobule at follow-up in the treatment group. No significant changes were noted in the placebo control group.

CONCLUSION

Due to the small sample size, results of the current study should be interpreted as preliminary. However, the observed pattern of activation of the frontoparietal network involved in WM found in the treatment group, suggests that mSMT training increases recruitment of attention- and WM-related neural networks. We conclude that mSMT treatment leads to changes in WM-related cerebral activation.

Abnormalities of the executive control network in multiple sclerosis phenotypes: An fMRI effective connectivity study

The Stroop interference task is a cognitively demanding task of executive control, a cognitive ability that is often impaired in patients with multiple sclerosis (MS). The aim of this study was to compare effective connectivity patterns within a network of brain regions involved in the Stroop task performance between MS patients with three disease clinical phenotypes [relapsing-remitting (RRMS), benign (BMS), and secondary progressive (SPMS)] and healthy subjects. Effective connectivity analysis was performed on Stroop task data using a novel method based on causal Bayes networks. Compared with controls, MS phenotypes were slower at performing the task and had reduced performance accuracy during incongruent trials that required increased cognitive control. MS phenotypes also exhibited connectivity abnormalities reflected as weaker shared connections, presence of extra connections (i.e., connections absent in the HC connectivity pattern), connection reversal, and loss. In SPMS and the BMS groups but not in the RRMS group, extra connections were associated with deficits in the Stroop task performance. In the BMS group, the response time associated with correct responses during the congruent condition showed a positive correlation with the left posterior parietal → dorsal anterior cingulate connection. In the SPMS group, performance accuracy during the congruent condition showed a negative correlation with the right insula → left insula connection. No associations between extra connections and behavioral performance measures were observed in the RRMS group. These results suggest that, depending on the phenotype, patients with MS use different strategies when cognitive control demands are high and rely on different network connections. Hum Brain Mapp, 37:2293-2304, 2016. © 2016 Wiley Periodicals, Inc.

Neuroimaging and cognition using functional near infrared spectroscopy (fNIRS) in multiple sclerosis

The present study utilized functional near infrared spectroscopy (fNIRS) to detect neural activation differences in the orbitofrontal brain region between individuals with multiple sclerosis (MS) and healthy controls (HCs) during a working memory (WM) task. Thirteen individuals with MS and 12 HCs underwent fNIRS recording while performing the n-back WM task with four levels of difficulty (0-, 1-, 2-, and 3-back). Subjects were fitted with the fNIRS cap consisting of 30 'optodes' positioned over the forehead. The results revealed different patterns of brain activation in MS and HCs. The MS group showed an increase in brain activation, as measured by the concentration of oxygenated hemoglobin (oxyHb), in the left superior frontal gyrus (LSFG) at lower task difficulty levels (i.e. 1-back), followed by a decrease at higher task difficulty (2- and 3-back) as compared with the HC group. HC group achieved higher accuracy than the MS group on the lower task loads (i.e. 0- and 1-back), however there were no performance differences between the groups at the higher task loads (i.e. 2- and 3-back). Taken together, the results suggest that individuals with MS experience a task with the lower cognitive load as more difficult than the HC group, and the brain activation patterns observed during the task confirm some of the previous findings from functional magnetic resonance imaging (fMRI) studies. This study is the first to investigate brain activation by utilizing the method of fNIRS in MS during the performance of a cognitive task.

Factors That Moderate Activity Limitation and Participation Restriction in People With Multiple Sclerosis

We examined the variables most associated with activity limitation (i.e., cooking) and participation restriction (i.e., employment) in 72 people with multiple sclerosis (MS). Participants underwent a comprehensive neuropsychological test battery assessing memory, executive functions, visual perception, and processing speed and completed questionnaires assessing activity, participation, fatigue, and affective symptoms. Results showed that processing speed was the only variable consistently significantly related to both activity and participation. When examining specific aspects of activity and participation in isolation, employment status was significantly associated with education level, visual memory, fatigue, and processing speed. Cooking ability was associated with performance on tasks of working memory, verbal memory, and processing speed. These findings suggest that processing speed is a primary cognitive factor in MS influencing quality of both activity and participation in everyday life.