Verbal episodic memory in 426 multiple sclerosis patients: impairment in encoding, retrieval or both?

Genetically Engineered Artificial Microvesicles Carrying Nerve Growth Factor Restrains the Progression of Autoimmune Encephalomyelitis in an Experimental Mouse Model

Multiple sclerosis (MS) is an incurable, progressive chronic autoimmune demyelinating disease. Therapy for MS is based on slowing down the processes of neurodegeneration and suppressing the immune system of patients. MS is accompanied by inflammation, axon-degeneration and neurogliosis in the central nervous system. One of the directions for a new effective treatment for MS is cellular, subcellular, as well as gene therapy. We investigated the therapeutic potential of adipose mesenchymal stem cell (ADMSC) derived, cytochalasin B induced artificial microvesicles (MVs) expressing nerve growth factor (NGF) on a mouse model of multiple sclerosis experimental autoimmune encephalomyelitis (EAE). These ADMSC-MVs-NGF were tested using histological, immunocytochemical and molecular genetic methods after being injected into the tail vein of animals on the 14th and 21st days post EAE induction. ADMSC-MVs-NGF contained the target protein inside the cytoplasm. Their injection into the caudal vein led to a significant decrease in neurogliosis at the 14th and 21st days post EAE induction. Artificial ADMSC-MVs-NGF stimulate axon regeneration and can modulate gliosis in the EAE model.

Relationship between subjective report and objective assessment of neurocognitive functioning in persons with multiple sclerosis

OBJECTIVE

Persons with multiple sclerosis (PwMS) are at increased risk for cognitive dysfunction. Considering the impact and potential ramifications of cognitive dysfunction, it is important that cognition is routinely assessed in PwMS. Thus, it is also important to identify a screener that is accurate and sensitive to MS-related cognitive difficulties, which can inform decisions for more resource-intensive neuropsychological testing. However, research focused on available self-report screeners has been mixed, such as with the Multiple Sclerosis Neuropsychological Screening Questionnaire (MSNQ). This study aims to clarify the relationship between subjective and objective assessment of cognitive functioning in MS by examining domain-specific performance and intraindividual variability (IIV).

METHODS

87 PwMS (F = 65, M = 22) completed a comprehensive neuropsychological battery which included self- and informant-report measures of neurocognitive functioning. Scores were examined in relation to mean performance on five domains of cognitive functioning and two measures of IIV.

RESULTS

The MSNQ-Self was inversely associated with executive function, verbal memory, and visual memory; it was not associated with IIV. The MSNQ-Informant was inversely associated with executive function and verbal memory, and positively associated with one measure of IIV. The MSNQ-Self showed a correlation of moderate effect size with depression (r = .39) while the MSNQ-Informant did not.

CONCLUSIONS

Results suggest that the MSNQ-Self and MSNQ-Informant show similar utility. Our findings also suggest that domains of executive function and memory may be most salient, thus more reflected in subjective reports of cognitive functioning. Future work should further examine the impact of mood disturbance with cognitive performance and IIV.

Effects of age, sex, and education on California Verbal Learning Test-II performance in a Chinese-speaking population

The California Verbal Learning Test-Second Edition (CVLT-II), is a commonly used tool to assess episodic memory. This study analyzed learning and memory characteristics in a cognitively healthy Chinese population, as well as the effects of age, sex and education on CVLT-II factors. In total, 246 healthy people aged 20–80 years and 29 persons with multiple sclerosis (MS) were included in this study and completed the CVLT-II. Factors including total learning, learning strategy, serial position effects, short-delay free and cued recall, long-delay free and cued recall, repetitions and intrusions during recall, hits and false positives of recognition, and total recognition discriminability were calculated. The effects of age, sex and education on these factors were analyzed using ANCOVA or independent two-sample t-tests and further confirmed by multiple regression analysis. The regression-based normative data were then computed by the equivalent scores method. Moreover, differences in learning and memory were compared between persons with MS and age-, sex- and education-matched healthy individuals. Most CVLT-II factors significantly differed between different age and education groups; in particular, better performance in total learning, recall, semantic clustering and recognition was observed in the younger and more educated groups than in the older and less educated groups. Male participants showed higher recency effect scores, more repetitions and fewer hits than female participants. Compared with healthy individuals, persons with MS showed extensive impairments in memory processes, such as learning, recall, learning strategy and recognition (p < 0.05). These findings indicated that verbal learning and memory were highly dependent on age and educational level but not strongly affected by sex. The CVLT-II effectively assesses episodic memory impairment in the Chinese-speaking population.

Quantitative Meta-analyses of Cognitive Abilities in Children With Pediatric-onset Multiple Sclerosis

Pediatric-onset multiple sclerosis (POMS), is the manifestation of multiple sclerosis in individuals before 18 years of age. About a third of children with POMS show some form of lower cognitive performance. The purpose of this study is to examine using quantitative meta-analyses the effect size of altered performance between children with and without POMS on overall intelligence quotient (IQ), information processing speed, and language functions. We searched the literature for studies that reported scores on cognitive tests administered to children with and without POMS. Studies were systematically reviewed using PRISMA guidelines. We analyzed data from 14 studies that examined 1283 children with and without POMS when cognitive categories consisted of five or more studies. Effect sizes, publication bias and potential confounds were considered. Significant cognitive differences are revealed for all categories with the strongest effect observed for overall IQ. A moderate effect is observed for information processing speed, and small effects for verbal fluency and verbal memory. Cognitive abilities present differently in children with POMS and a better understanding of this manifestation will inform intervention and remediation tools that can improve clinical and educational practice for the benefit of children with POMS.

Predicting Neuropsychological Impairment in Relapsing Remitting Multiple Sclerosis: The Role of Clinical Measures, Treatment, and Neuropsychiatry Symptoms

OBJECTIVE

This retrospective observational study aimed to define neuropsychological impairment (NI) profiles and determine the influence of clinical, demographic, and neuropsychiatric measures in specific cognitive domains in a cohort of relapsing-remitting multiple sclerosis (RRMS) patients.

METHODS

Ninety-one RRMS patients underwent a neurological examination and a brief neuropsychological assessment. Patients were classified according to the disease-modifying therapies (DMTs) received (platform or high-efficacy). Differences between groups and multiple regression analyses were performed to determine the predictive value of the assessed measures in cognitive performance.

RESULTS

More than two-thirds of the patients showed NI. Specifically, mild to moderate NI was presented in approximately half of the participants. Paced Auditory Serial Addition Test (PASAT-3) and Symbol Digit Modalities Test (SDMT) were the most frequently impaired cognitive tests (45.3% and 41.3%, respectively) followed by phonemic verbal fluency (PVF) (27.8%). Expanded Disability Status Scale (EDSS), age, depressive symptoms, and disease duration were the best predictors of SDMT (R2 = .34; p < .01), whereas disease duration, EDSS, and anxiety-state levels predicted PASAT-3 (R2 = .33, p < .01). Educational level, age, EDSS, and depressive symptoms demonstrated the strongest association with PVF (R2 = .31, p < .01).

CONCLUSIONS

Our results indicated a significant prevalence of NI in RRMS patients that was not dependent on the DMT type. In addition to the meaningful working memory (PASAT-3) and information processing speed (SDMT) impairments found, PVF deficits may also be an important marker of cognitive impairment in RRMS patients. This study supports the relevance of standard clinical measures and reinforces the importance of quantifying clinical and neuropsychiatric symptoms to predict subsequent cognitive performance on a similar multiple sclerosis phenotype and disease stage.

Memory in multiple sclerosis: A reappraisal using the item specific deficit approach

OBJECTIVE

As many as 65% of people with multiple sclerosis (MS) have clinically significant memory impairment, but the nature of this deficit is controversial. Some investigations suggest that an inability to retrieve newly learned information from memory is prominent, whereas others imply that compromised acquisition accounts for impairment. Prior research has not simultaneously evaluated acquisition and retrieval processes in MS, and fewer have attempted to account for initial acquisition when studying retrieval. The Item Specific Deficit Approach (ISDA) offers a method of quantifying acquisition, retrieval, and retention processes, with the latter two mechanisms being adjusted for initial acquisition. To simultaneously quantify acquisition and retrieval abilities, the ISDA was applied to list learning performance in two independent samples of people with MS and corresponding healthy comparison groups.

PARTICIPANTS AND METHODS

Study 1 included 85 people with MS and 47 healthy individuals. Study 2 involved a separate sample of 79 people with MS and 22 healthy people. They were administered neuropsychological batteries, and participants with MS were classified as globally impaired or unimpaired. The California Verbal Learning Test-II was administered to assess new-learning in both studies, and responses were scored using the ISDA.

RESULTS

Both studies revealed that cognitively impaired people with MS manifest weaknesses involving acquisition and retrieval. Nearly identical effect sizes emerged across samples, with cognitive impairment achieving a medium effect upon acquisition and a large effect upon retrieval.

CONCLUSIONS

These findings accord well with previous research showing diminished acquisition and retrieval among people with MS. The results may also reconcile contradictory findings in the extant literature by showing that memory impairment in MS is not exclusively attributable to either acquisition or retrieval. Rather, both processes may manifest across people with MS. The replication across samples with nearly identical effect sizes implies that these effects are reliable and possess external validity. These data hold implications for memory rehabilitation interventions involving people with MS, and suggest that acquisition and retrieval processes should be addressed in treatment. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Evaluating the relationship between working memory and information processing speed in multiple sclerosis

The aim of the present study was to evaluate the effect of information processing speed on the functioning of specific working memory components, i.e. phonological loop, visuospatial sketchpad, central executive and episodic buffer. Cognitive tasks that assess working memory ("word lists recall" for the phonological loop, "block recall" for the spatial component of visuospatial sketchpad, "listening recall" for the central executive and "immediate story recall" for the episodic buffer) and information processing speed (symbol digit modalities test- oral form) were administered to 38 patients with multiple sclerosis. Results showed that the central executive and episodic buffer components were significantly related to information processing speed. However, when age was included in the regression model, information processing speed significantly predicted only the episodic buffer scores. Further research on the relationship between the episodic buffer and information processing speed is recommended.

Memory improvement in multiple sclerosis after an extensive cognitive rehabilitation program in groups with a multicenter double-blind randomized trial

OBJECTIVE

The aim of this study is to determine the effectiveness of an extended cognitive rehabilitation program in group's sessions in multiple sclerosis.

DESIGN

Double-blind multicenter randomized trial.

PARTICIPANTS

People with multiple sclerosis of 18 to 60 years, Expanded Disability Status Scale ⩽6.0, mild to moderate cognitive impairment.

INTERVENTIONS

They were randomized into cognitive rehabilitation program (ProCog-SEP) or in a placebo program. ProCog-SEP comprises 13 group's sessions over 6 months and includes psychoeducational advices and cognitive exercises. Placebo program included non-cognitive exercises. No strategy and no cognitive advice were provided.

MAIN MEASURES

The primary endpoint was the percentage of verbal memory learning measured by the Selective Reminding Test. A comprehensive neuropsychological assessment is carried out before and after interventions by a neuropsychologist blinded to intervention. Effectiveness of the ProCog-SEP versus Placebo has been verified using linear regression models.

RESULTS

In total, 128 participants were randomized and 110 were included in the study after planning session in groups; 101 completed this trial (77.2% females); mean age: 46.1 years (±9.6); disease duration: 11.8 years (±7.5). ProCog-SEP was more effective in increasing in learning index (9.21 (95% confidence interval (CI): 1.43, 16.99); p = 0.02) and in working memory on manipulation (0.63 (95% CI: 0.17, 1.09); p = 0.01), and updating capacities (-1.1 (95% CI: -2.13, -0.06); p = 0.04). No difference was observed for other neuropsychological outcomes. Regarding quality of life outcomes, no change was observed between the two groups.

CONCLUSION

These findings suggest that ProCog-SEP could improve verbal learning abilities and working memory in people with multiple sclerosis. These improvements were observed with 13 group sessions over 6 months.

Memory Impairment in Relapsing-Remitting Multiple Sclerosis Using a Challenging Semantic Interference Task

Objective: Episodic memory is frequently impaired in Multiple Sclerosis (MS), but the cognitive characteristics and neuropsychological processes involved remain controversial. Our aim was to study episodic memory dysfunction in MS, using the LASSI-L, a novel memory-based cognitive stress test that uses a new paradigm that capitalizes on semantic interference. Methods: Cross-sectional study in which 93 patients with MS (relapsing-remitting) and 124 healthy controls were included. The LASSI-L test was administered to all participants, as well as a comprehensive neuropsychological battery including a selective reminding test. MS patients were divided into two groups, with cognitive impairment (CI-MS) and cognitively preserved (CP-MS). Results: Reliability of the LASSI-L test was high (Cronbach's alpha 0.892) and there were less ceiling effects. MS patients scored lower than controls on all LASSI-L subtests, except for maximum storage of the initial target items (CRA2). Effect sizes were moderate-large. A delay in learning, difficulties in retroactive semantic interference, failure to recover from proactive semantic interference, and delayed recall were the most frequent findings in MS patients. Scores associated with maximum storage capacity, and retroactive semantic interference were the most strongly associated with cognitive impairment and employment status. Conclusion: We found that deficits in maximum learning, difficulties in recovery from the effects of proactive semantic interference and retroactive semantic interference are three important breakdowns in episodic memory deficits among patients with MS. The LASSI-L showed good psychometric and diagnostic properties. Overall, our study supports the utility of the LASSI-L, as a new cognitive test, useful for neuropsychological assessment in MS in clinical and research settings.

False memories in relapsing remitting multiple sclerosis patients: A preliminary investigation with the DRM paradigm

BACKGROUND

Memory impairment is one of the most frequently and early detected impairment in multiple sclerosis (MS) patients. Several authors have argued that when a failure occurs in the retrieval of lexical information, this might be due to a reduction of the lexical pool, related to semantic memory. Here we further investigated memory alteration in MS patients, by focusing on memory distortions (i.e., false memories) for semantically-related material.

METHODS

A group of 40 consecutive relapsing remitting MS (RRMS) patients and a matched control group of 40 healthy controls performed the Deese-Roediger-McDermott (DRM), a false memory task for lists of associated words.

RESULTS

At recall, RRMS patients reported a reduced number of false recalls for semantically-related but non-presented items (i.e., critical false recalls) compared to HCs; at recognition, RRMS patients showed a reduced level of confidence for false recognitions of critical items.

CONCLUSION

We found a reduced susceptibility to false memories in RRMS patients compared to HCs. The potential mechanisms underlying this effect are discussed in light of the alterations in the structure of semantic memory.

Hippocampal structural and functional integrity in multiple sclerosis patients with or without memory impairment: a multimodal neuroimaging study

The increasing evidence for a pure amnestic-like profile in multiple sclerosis (MS) introduces the role of hippocampal formation in MS episodic memory function. The aim of the present study was to investigate structural and functional hippocampal changes in mildly-disabled MS patients with and without memory impairment. Thirty-one MS patients with or without memory impairment and 16 healthy controls (HC) underwent MRI in a 3.0 T MRI scanner. Patients were categorized as memory preserved (MP) and memory impaired (MI) based on verbal and visual memory scores extracted from the Brief Repeatable Neuropsychological Battery. The acquisition protocol included high-resolution 3D-T1-weighted, diffusion weighted imaging and echo-planar imaging sequences for the analysis of hippocampal gray matter (GM) density, perforant pathway area (PPA) tractography, and hippocampal functional connectivity (FC), respectively. Compared to HC, we found decreased left and bilateral hippocampal GM density in MP and MI patients, respectively, decreased fractional anisotropy and increased radial diffusivity on left PPA in MI patients, and reduced FC in MI between left hippocampus and left superior frontal gyrus, precuneus/posterior cingulated cortex and lateral occipital gyrus/angular gyrus. The only differences between MP and MI were found in FC. Specifically, MP patients showed FC changes between left hippocampus and right temporo-occipital fusiform/lingual gyrus (increased FC) as well as supramarginal gyrus (decreased FC). In conclusion, we highlight the early detection of structural hippocampal changes in MS without neuropsychologically-detected memory deficits and decreased hippocampal FC in MS patients with impaired memory performance, when both GM density and PPA integrity are affected.

Relationship Between Anxiety and Cognition in Multiple Sclerosis: Implications for Treatment

Background

Anxiety, which is very prevalent in multiple sclerosis (MS) but understudied, has been shown to negatively affect cognition in many different populations. Slowed information processing speed underlies most cognitive impairments in MS, including verbal learning. The aim of this study was to look at how anxiety influences cognition-specifically processing speed and verbal learning-in MS.

Methods

Eligibility criteria were adults (≥18 years) who had a diagnosis of clinically definite MS and had participated in neuropsychological research projects. A retrospective medical record review was conducted on the neuropsychological testing data. Two hierarchical multiple regressions were conducted to determine the unique contributions of processing speed and anxiety on verbal learning in MS, after adjusting for demographic and disability variables. Two separate mediation analyses were conducted to determine the relationship between processing speed, verbal learning, and anxiety.

Results

Participants (N = 141) ranged in age from 18-91 years. Based on the multiple regression analyses, processing speed (β = 0.55, ΔR ² = 0.27, P < .001) and anxiety (β = -0.34, ΔR ² = 0.11, P < .001) were uniquely significant predictors of verbal learning. Based on the mediation analyses, there was a significant indirect effect of anxiety on verbal learning through processing speed (ab = -0.31, 95% CI = -0.60 to -0.09). There was also a significant indirect effect of processing speed on verbal learning through anxiety (ab = -0.05, 95% CI = 0.01 to 0.12).

Conclusions

Results suggest a bidirectional relationship of anxiety and processing speed on verbal learning in MS. Anxiety has a significant effect on cognition and should not be overlooked. Interventions targeting anxiety may improve cognition in MS.

Working memory profiles of patients with multiple sclerosis: Where does the impairment lie?

Introduction: Previous studies have mostly provided general estimations regarding Working Memory impairment in patients with Multiple Sclerosis. The aim of the present study was to investigate the relative degree of impairment in the four Working Memory components in Multiple Sclerosis. Method: Thirty-eight patients diagnosed with MS and 27 matched controls were assessed using 12 different cognitive tasks of the four components, i.e. phonological loop, visuospatial sketchpad, central executive and episodic buffer. More precisely, Greek translated and adapted versions of the following tasks were administered: Digit recall, Word recall, Non-word recall, Block recall, Mazes recall, Visual Patterns recall, Backward Digit recall, Backward Block recall, Listening recall, Logical Memory I-Immediate Story recall and Greek Verbal Learning Test, which is based on the California Verbal Learning Test. Results: The phonological loop, the central executive and the spatial subcomponent of the visuospatial sketchpad were found to be equally disrupted in MS patients. The episodic buffer was found to be more heavily affected. On the other hand, the visual subcomponent of the visuospatial sketchpad proved to be preserved. Conclusions: WM subcomponents are differentially affected in patients with MS. This novel finding is discussed within the framework of existing knowledge regarding WM impairment in MS.

Relationship between episodic memory and volume of the brain regions of two functional cortical memory systems in multiple sclerosis

BACKGROUND/OBJECTIVE

Two functional networks are proposed as neuronal support for the complex processes of memory: the anterior temporal and the medial posterior systems. We examined the atrophy of hippocampus (HC) and of those areas constituting the two functional memory systems in multiple sclerosis (MS) patients with low disability.

METHODS

Episodic memory (EM) was assessed in 88 relapsing MS patients and in 40 healthy controls using Wechsler Memory Scale III (Spanish adaptation). FreeSurfer software was used to calculate normalized volume of total cortex, grey matter, white matter, subcortical grey matter (thalamus and striatum), HC and both the anterior temporal (entorhinal, ventral temporopolar, lateral orbitofrontal, amygdala) and posterior medial systems (thalamus, parahippocampal, posterior cingulate, precuneus, lateral parietal and medial prefrontal). Linear regression analysis was used to identify predictors of memory performance.

RESULTS

Total grey matter and cortex volumes correlated with all subtypes of EM, and the precuneus volume correlated with overall, immediate and delayed memories. Univariant regression analysis identified an association between the volumes of the posterior medial memory network regions and EM scores. The volume of the left precuneus area was the unique and independent predictor for all EM subtypes except for visual memory, for which left HC volume was also an independent predictor.

CONCLUSION

Left precuneus volume was the best predictor of memory in relapsing MS patients with low disability and mild deficits in EM.

Longitudinal analysis of verbal episodic memory in patients with relapsing-remitting multiple sclerosis

OBJECTIVE

A 4.5-year follow-up study was conducted to characterize baseline verbal episodic memory (VEM) and its behavior and to assess the effects of relapsing-remitting multiple sclerosis (RRMS) on this domain.

METHODS

Twenty-nine patients with RRMS underwent two neuropsychological assessments performed an average of 4.5 years apart. Twenty-six control participants underwent a single neuropsychological assessment. A significance level of p < 0.005 was adopted to denote a significant difference between the groups on the Mann Whitney and Wilcoxon paired statistical analyses.

RESULTS

No statistical difference was found in the results of the VEM tests between the first and second neuropsychological assessments of the patients. However, a statistical difference was evident between the patient and control groups in the results of the VEM tests.

CONCLUSION

The patient group showed changes in the VEM relative to the control group. After approximately 4.5 years of disease, the patient performance on the VEM stabilized or improved.

Cognitive impairment in multiple sclerosis - a review of current knowledge and recent research

Multiple sclerosis (MS) is a chronic, progressive disease of the central nervous system that is characterised by inflammatory damage to the myelin sheath. Though often neglected, cognitive impairment is a common feature of MS that affects 43-70% of patients. It has a sophisticated neuroanatomic and pathophysiologic background and disturbs such vital cognitive domains as speed of information processing, memory, attention, executive functions and visual perceptual functions. In recent years there has been growing interest in neuroimaging findings with regard to cognitive impairment in MS. The possible options of managing cognitive dysfunction in MS are pharmacologic interventions, cognitive rehabilitation and exercise training; however, not enough evidence has been presented in this field. The aim of our article is to provide current knowledge on cognitive impairment in MS based on the most recent scientific results and conclusions with regard to affected cognitive domains, neuropsychological assessment, underlying mechanisms of this disturbance, neuroimaging findings and therapeutic options.

The clinical utility of metacognitive beliefs and processes in emotional distress in people with multiple sclerosis

AIM

Multiple sclerosis (MS) is a chronic demyelinating disease that poses significant life challenges. Depression and anxiety often occur in people with MS (PwMS). An information processing model of psychopathology, the Self-Regulatory Executive Function (S-REF) model specifies that maladaptive metacognitive beliefs play a fundamental role in the development and maintenance of distress. The model also asserts that a style of thinking known as the cognitive attentional syndrome (CAS), which consists of worry and rumination, focusing on sources of threat, and unhelpful coping responses, is common across all psychological conditions. This study investigated for the first time whether metacognitive beliefs explained additional variance in distress in PwMS, after accounting for demographic, clinical, and illness appraisal variables.

METHOD

One hundred and thirty-two participants with MS completed self-report questionnaires measuring distress, fatigue, pain, metacognitive beliefs, illness appraisals, and the CAS. Hierarchical regression modelling was used to test whether metacognitive beliefs accounted for distress. Mediational modelling examined if the CAS mediated the association between metacognitive beliefs and distress.

RESULTS

Metacognitive beliefs made a unique contribution to distress, over and above demographic and clinical variables, and illness appraisals. The CAS fully mediated the relationship between positive metacognitive beliefs and distress, and partially mediated the relationship between negative metacognitive beliefs and distress.

CONCLUSIONS

Metacognitive beliefs are associated with emotional distress in PwMS, and the CAS mediates this relationship. Future studies should examine if modification of metacognitive beliefs and processes in PwMS will lead to effective alleviation of emotional distress.

Memory and selective attention in multiple sclerosis: cross-sectional computer-based assessment in a large outpatient sample

Cognitive impairments may have a severe impact on everyday functioning and quality of life of patients with multiple sclerosis (MS). However, there are some methodological problems in the assessment and only a few studies allow a representative estimate of the prevalence and severity of cognitive impairments in MS patients. We applied a computer-based method, the memory and attention test (MAT), in 531 outpatients with MS, who were assessed at nine neurological practices or specialized outpatient clinics. The findings were compared with those obtained in an age-, sex- and education-matched control group of 84 healthy subjects. Episodic short-term memory was substantially decreased in the MS patients. About 20% of them reached a score of only less than two standard deviations below the mean of the control group. The episodic short-term memory score was negatively correlated with the EDSS score. Minor but also significant impairments in the MS patients were found for verbal short-term memory, episodic working memory and selective attention. The computer-based MAT was found to be useful for a routine assessment of cognition in MS outpatients.

Clinical and cognitive implications of cerebrospinal fluid oligoclonal bands in multiple sclerosis patients

The presence of cerebrospinal fluid oligoclonal bands (CSF-OCB) in Caucasian patients with multiple sclerosis (MS) is supportive of diagnosis, though the relation with patients' clinical and specifically cognitive features has never been established or thoroughly examined. Thus, we investigated the clinical and for the first time the cognitive profile of MS patients in relation to CSF-OCB. We studied 108 patients with and without OCB and recorded demographic characteristics and detailed clinical data. A comprehensive neuropsychological battery covering different cognitive domains (attention/processing speed, memory, perception/constructions, reasoning, executive functions) was administered to MS patients and 142 demographically related healthy controls (HC). We did not find any significant differences between patients with and without OCB on demographic and clinical parameters (p > 0.05), including subtype and brain neuroimaging findings. Results revealed significantly higher cognitive scores in HC compared to both OCB subgroups, with more widespread cognitive changes in patients with OCB. Analysis between OCB subgroups showed significantly worse performance in patients with OCB on visual memory (Rey's complex figure test-recall; p = 0.006). Concluding, the presence of CSF-OCB in our MS patients tends to be related to more widespread cognitive changes, specifically worse visual memory. Future longitudinal studies in different populations are warranted to better clarify the clinical and cognitive characteristics related to CSF-OCB which could serve as early biomarker in disease monitoring.

Spatial reference memory deficits precede motor dysfunction in an experimental autoimmune encephalomyelitis model: the role of kallikrein-kinin system

Multiple sclerosis (MS) is a progressive T cell-mediated autoimmune demyelinating inflammatory disease of the central nervous system (CNS). Although it is recognized that cognitive deficits represent a manifestation of the disease, the underlying pathogenic mechanisms remain unknown. Here we provide evidence of spatial reference memory impairments during the pre-motor phase of experimental autoimmune encephalomyelitis (EAE) in mice. Specifically, these cognitive deficits were accompanied by down-regulation of choline acetyltransferase (ChAT) mRNA expression on day 5 and 11 post-immunization, and up-regulation of inflammatory cytokines in the hippocampus and prefrontal cortex. Moreover, a marked increase in B1R mRNA expression occurred selectively in the hippocampus, whereas protein level was up-regulated in both brain areas. Genetic deletion of kinin B1R attenuated cognitive deficits and cholinergic dysfunction, and blocked mRNA expression of both IL-17 and IFN-γ in the prefrontal cortex, lymph node and spleen of mice subjected to EAE. The discovery of kinin receptors, mainly B1R, as a target for controlling neuroinflammatory response, as well as the cognitive deficits induced by EAE may foster the therapeutic exploitation of the kallikrein-kinin system (KKS), in particular for the treatment of autoimmune disorders, such as MS, mainly during pre-symptomatic phase.

Cognitive impairment in multiple sclerosis

Cognitive impairment (CI) is a serious complication of multiple sclerosis (MS), and the domains affected are well established, but new affected domains such as theory of mind are still being identified. The evidence that disease-modifying therapies (DMTs) improve and prevent the development of CI in MS is not solid. Recent studies on the prevalence of CI in MS among people treated with DMT, although not as solid as studies completed prior to DMT introduction, suggest that CI remains a problem even among people on DMTs and that CI occurs frequently even at the very earliest stages of MS. Functional MRI studies and studies using diffusion tractography show that the impact of lesions on cognition depends on the particular cortical networks affected and their plasticity. Cognitive rehabilitation and L-amphetamine appear promising symptomatic treatments for CI in MS, while, cholinesterase inhibitors and memantine have failed, and data on Ginkgo and exercise are limited. We need more work to understand better CI in MS and develop treatments for this serious complication of MS.