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.
Objective
The current study examines the efficacy of speed of processing training (SOPT) to improve processing speed (PS) in individuals with multiple sclerosis (MS). Outcomes included changes in the ...useful field of view (UFOV) and neuropsychological evaluation (NPE).
Methods
This double-blind, placebo-controlled randomized clinical trial included 84 participants with clinically definite MS and impaired PS, 43 in the treatment group and 41 in the placebo control group. Participants completed a baseline NPE and a repeat NPE post-treatment. The treatment group was randomized to booster sessions or no contact. Long-term follow-up assessments were completed 6 months after treatment.
Results
A significant effect of SOPT was observed on both the UFOV (large effect) and pattern comparison with a similar pattern of results noted on letter comparison, albeit at a trend level. The treatment effect was maintained 6 months later. The impact of booster sessions was not significant. Correlations between degree of improvement on the UFOV and the number of levels completed within each training task were significant for both speed and divided attention indicating that completion of more levels of training correlated with greater benefit.
Conclusion
SOPT is effective for treating PS deficits in MS with benefit documented on both the UFOV and a neuropsychological measure of PS. Less benefit was observed as the outcome measures became more distinct in cognitive demands from the treatment. Long-term maintenance was observed. The number of training levels completed within the 10-sessions exerted a significant impact on treatment benefit, with more levels completed resulting in greater benefit.
This study examined the influence of processing speed (PS) on benefit from treatment with the Kessler Foundation modified Story Memory Technique® (KF-mSMT®), a cognitive rehabilitation intervention ...shown to improve new learning and memory in traumatic brain injury (TBI).
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62 participants with moderate-to-severe TBI were included, 31 assigned to the treatment group and 31 to the placebo-control group.
Double-blind, placebo-controlled, randomized clinical trial. The present study represents a post-hoc analysis to examine the role of PS on treatment efficacy.
Baseline and follow-up neuropsychological assessment including the California Verbal Learning Test, Second Edition (CVLT-II), Memory Assessment Scales - Prose Memory (MAS-PM) and the Symbol Digit Modalities Test (SDMT).
A treatment effect was not observed on the CVLT-II learning slope in the treatment group relative to the placebo group post-treatment, after co-varying for education, baseline CVLT slope and PS performance. However, performance on a measure of PS, the SDMT, was a significant predictor of post-treatment change following KF-mSMT® treatment. PS was not a significant predictor of benefit from treatment as documented by the MAS-PM immediate or delayed recall score, both of which showed a significant treatment effect.
Performance on measures of cognitive dysfunction aside from learning and memory impact the benefit from KF-mSMT® treatment. Implications for cognitive rehabilitation for individuals with TBI are discussed.
Introduction Individuals with multiple sclerosis (MS) frequently experience visual and oculomotor symptoms that may impact and confound neuropsychological assessments of information processing speed ...(IPS). In this study, we examined the effect of the psychostimulant methylphenidate on oculomotor function and the association between change in oculomotor speed and change in information processing speed. Methods We used a repeated measures crossover design in which a sample of 11 participants with MS were randomly assigned to one of two treatment arms: one that received methylphenidate for 4 weeks and another that received a placebo for 4 weeks. After a 7-day washout period, the treatments were crossed over. The King Devick test, the Symbol Digit Modalities Test, and the Paced Auditory Serial Addition Test were administered at baseline and after each of the two study arms. Results We found a significant improvement in oculomotor speed in the methylphenidate condition as compared to placebo. This improvement was significantly correlated with improvement on a visuomotor assessment of IPS (Symbol Digit Modalities Test), but no such association was found for an auditory-verbal assessment of IPS (Paced Auditory Serial Addition Test). Discussion These findings suggest that individuals with MS experience improved oculomotor speed while taking methylphenidate, which may, in turn, improve performance on assessments of IPS with visuomotor demands.
Individuals with Multiple Sclerosis (MS) have significant impairments in processing speed (PS) and such impairments may underlie other cognitive deficits common in MS and limit performance of ...everyday life activities.
To examine the efficacy of a computerized PS intervention, Speed of Processing Training (SPT), in persons with MS on PS, memory and everyday activities.
Twenty-one individuals with clinically definite MS and an objectively assessed impairment in PS were included in a controlled randomized clinical trial, randomly assigned to a treatment group or a control group. Participants were assessed prior to and within 1 week of completing the treatment. Outcome measures included traditional neuropsychological tests measuring PS and memory, and an assessment of PS in daily life activities.
The treatment group showed a significant improvement on neuropsychological tests of PS and new learning and memory. A significant improvement was additionally noted in the treatment group on measures of PS in everyday life. These changes were not observed in the control group.
Results provide preliminary data in support of SPT in treating PS deficits in persons with MS. Additional research is needed with larger samples and more comprehensive outcome measures.
Introduction: Learning and memory deficits are prevalent following moderate to severe traumatic brain injury (TBI), affecting between 54% and 84% of impacted individuals.
Objective: The current study ...examined learning performance on two tests of verbal memory: the OT-SRT and the CVLT-II.
Methods: Sixty-eight participants with TBI performed the OT-SRT and the CVLT-II on two different days. Additionally, all participants completed cognitive tests assessing processing speed, working memory and executive functions. By definition, all participants with TBI were identified as having impaired learning on the OT-SRT, however only 38 were also identified as impaired on the CVLT-II. The sample was thus divided into two groups, those who failed both tests (Fail-2) and those who failed only the OT-SRT (Fail-1).
Results: The Failed-1 group showed significantly better performance in processing speed, working memory and executive functions compared to the Fail-2 group. On the CVLT-II, the Fail-1 group performed significantly better on the number of words recalled on trials 1 and 5 compared to the Fail-2 group. Both groups performed similarly the OT-SRT.
Discussion: The CVLT-II and the OT-SRT are not equivalent tests and should not be used interchangeably.
•Brevetoxin exposure leads to human and wildlife health risks.•Adverse outcome pathway for brevetoxin-induced immunotoxicity in marine fauna.•The adverse outcome pathway can be implemented to guide ...future brevetoxin research.
Red tide events, caused by a toxin producing dinoflagellate, Karenia brevis, occur annually in Florida and Texas. These events lead to health risks for both humans and wildlife that utilize coastal environments. Brevetoxins, potent lipophilic neurotoxins produced by K. brevis, modulate immune responses in laboratory studies with model organisms and in the natural environment in both humans and wildlife. Studies show that brevetoxins activate immune cells, stimulate production of gamma-globulins, cytokines, and neutrophils, modulate lysozyme activity, induce apoptosis, and modulate lymphocyte proliferation in marine species. The objective of this review was to summarize brevetoxin-induced immunotoxicity in marine animals based on available peer-reviewed literature about K. brevis blooms and associated health concerns and propose putative toxicity pathways. This review identifies knowledge gaps within current brevetoxin induced immunotoxicity research, including assessing the long-term impacts of brevetoxin exposure, elucidating the mechanistic linkages between brevetoxins and immune cells, and evaluating repeated and chronic versus acute brevetoxin exposure implications on overall organismal health. The putative immunotoxicity pathways based on evidence from brevetoxin-exposure in marine fauna described in this review represent a useful tool and resource for researchers, wildlife managers, and policy makers. This review and proposed putative immunotoxicity pathways will inform decisions regarding the risks of algal blooms, as it pertains to marine animal health.
We compared the California Learning Verbal Test II (CVLT II) and the Open Trial-Selective Reminding Test (OT-SRT) in assessing learning in persons with Multiple Sclerosis. One-hundred and twelve ...participants with multiple sclerosis performed the OT-SRT and the CVLT II on two different days. All participants completed additional cognitive tests assessing information processing speed (IPS), working memory (WM), and executive functions (EF). By definition, all participants were identified as having impaired learning on the OT-SRT (i.e., z score <−1.0); however, only 38 participants (33.9%) were identified as having impaired learning on the CVLT II (i.e., a z score <−1 total correct responses trials 1-5). The sample was thus divided into two groups, those who failed both tests (Fail-2) and those who failed only one (Fail-1). The Fail-2 group showed poorer performance on EF, WM and IPS in comparison with the Fail-1 group. On the CVLT II, the Fail-1 group showed a significantly greater improvement between trials 1 and 5, as compared with the Fail-2 group. However, the two groups performed similarly on the OT-SRT. Correlation analysis showed that EF is positively correlated with CVLT II learning slope but not with OT-SRT learning slope. The CVLT II and the OT-SRT are not equivalent tests: while the CVLT II appears to be sensitive to overall cognitive dysfunction, the OT-SRT is more sensitive to focal learning and memory impairments.
•Olfactory functions are impaired in MS.•Olfactory dysfunction is associated with worse cognitive and everyday life performance and as well as with lower quality of life.•Olfactory function should be ...considered as a clinical marker related to MS disability.
Olfactory dysfunction is a common symptom of multiple sclerosis (MS). The questions of whether and to what degree olfactory dysfunction can serve as a clinical marker of MS disability (i.e. cognitive impairments and functional limitations) are not yet answered. The current study aimed to explore associations between olfactory function (i.e. smell identification) with cognitive capacities, functional performance and quality of life (QOL) in persons with MS.
Olfactory function was measured by the University of Pennsylvania Smell Identification Test (UPSIT). Functional ability was assessed by the Actual RealityTM (AR) task. QOL was assessed by the Multiple Sclerosis Quality of Life-54 (MSQOL-54). Cognition was assessed by the Brief International Cognitive Assessment for MS (BICAMS) in 23 MS patients and 15 matched healthy controls.
MS patients had lower UPSIT scores than healthy controls. Worse UPSIT scores were associated with reduced performances on the BICAMS and AR task as well as lower MSQOL-54 scores. Specifically, UPSIT scores were related to MSQOL-54 scores independent of BICAMS composite scores, while the relationship between UPSIT score and AR performance was mediated by BICAMS composite score.
This study confirms previous studies which concluded that olfactory function is impaired in MS. Furthermore, olfactory dysfunction is related to limitations in activity performance and QOL. Taken together with previous studies, olfactory function may be considered as a clinical marker related to MS disability. Longitudinal studies are needed to confirm these results.
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