Cognitive function in multiple sclerosis: A long-term look on the bright side

Exploring the relationship between manual dexterity and cognition in people with multiple sclerosis: 9-hole peg and multiple cognitive functions

AIM AND RATIONALE

Problems with manual dexterity and cognition impact the everyday performance of people with multiple sclerosis (PwMS). Accumulated findings point to the relationship between deficits in manual dexterity and auditory domains of cognition with a lack of evidence on visuospatial and verbal aspects of cognitive functioning. Therefore, this study explores the relationship between manual dexterity and cognition in a cohort of PwMS.

METHOD

This cross-sectional study collected data from 63 PwMS aged 22 to 55 through a convenient sampling method. Participants were diagnosed with relapsing-remitting multiple sclerosis (RRMS). Cognition was measured using a multi-domain computerized cognitive testing, NeuroTrax, and manual dexterity was measured using a 9-hole peg assessment. Spearman correlation was used to identify the correlation among cognition subtests as well as with manual dexterity. Linear regression analysis was also conducted to identify whether manual dexterity predicts cognitive functioning.

RESULTS

A significant negative correlation was found between 9-hole peg scores and global cognitive scores (GCS), r = -0.34, p = 006. The manual dexterity scores were also shown to predict GCS, R2= 0.165, p = 0.001.

CONCLUSION

Manual dexterity was found to not only predict cognitive dysfunction but was also associated with multiple cognitive domains. Understanding the relationship between manual dexterity and cognition and the inferred progression of deficits can assist clinicians to provide interventions at earlier stages of disease progression to potentially increase daily functioning and quality of life (QoL).

Attention Deficit/Hyperactivity Disorder in Children with Multiple Sclerosis

BACKGROUND

Multiple sclerosis (MS) is a chronic neurological autoimmune disease; pediatric-onset multiple sclerosis (POMS) represents 5% to 10% of total MS population. Children with POMS may experience attention difficulties due to the disease's impact on the central nervous system. However, little is known regarding Attention Deficit Hyperactivity Disorder (ADHD) in POMS, and its relation to cognitive performance.

METHODS

A retrospective case review was conducted using medical records of 66 children and adolescent patients diagnosed with POMS between 2012 and 2021 in a MS center of a tertiary medical center. All patients had undergone routine clinical neurological examinations and had been assessed for a diagnosis of ADHD by a department pediatric neurologist. In addition, sociodemographic data, disease-related variables, and cognitive performance were collected.

RESULTS

Of the 66 patients, 31 (47%) had a diagnosis of ADHD; 29 (44%) had cognitive impairment. Moreover, we identified four different profiles of POMS: those with only ADHD (17, 26%); only cognitive impairment (15, 23%), ADHD and cognitive impairment (14, 21%), and only POMS (20, 30%). A significant difference in disease duration was found among the four profiles [F(3,65) = 8.17, p < .001, η² = 0.29], indicating that patients with ADHD and cognitive impairment were characterized by longer disease duration.

CONCLUSIONS

ADHD may be prominently involved in POMS, even during the early stages of the disease and early diagnosis is crucial in order to provide appropriate interventions and support.

5 -Alpha-dihydroxyprogesterone may contribute to perceptual processing and attention of the cases with relapsing remitting multiple sclerosis

Neurosteroids (NSs) are endogenous steroid hormones, which are synthesised and metabolised within the central nervous system (CNS). NSs aid myelination and glial differentiation and modulate cognitive functions. Herein, we aim to investigate the relationship between NS levels, 5-alpha-dihydroxyprogesterone (5-α-DHP) and allopregnanolone (ALPG), and their relationship with cognitive changes in relapsing remitting MS patients.A total of 43 cases with well controlled, relapsing remitting MS composed the study group. The control group included 21 age and gender matched healthy controls (HC). MS patients were assessed by calculating Expanded Disability Status Scale (EDSS) scores, and the Brief Repeatable Battery of Neuropsychological Tests (BRBNT) was performed in both MS group and HC. Levels of 5-α-DHP and ALPG levels were also evaluated for each participant.The median level of 5-α-DHP was 48 [IQR: 39.2-144.2] pg/mcgL in the MS group and 68.4 [IQR: 57.1-365.9] pg/mcgL in HC (p = 0.02). The median ALPG level was found to be 56.5 [IQR: 37.7-75.4] pg/mcgL in the MS group and 43.9 [IQR: 29.4-70.2] pg/mcgL in HC (p = 0.1). In both groups 5-α-DHP levels were positively correlated with Symbol Digit Modalities Test (SDMT) scores (HC: p = 0.01, r = 0.3 and MS: p = 0.03, r = 0.3). In the MS group, higher EDSS scores were associated with lower scores on Spatial Recall Test (SPART)-Delayed (p = 0.009, r= -0.4) and SDMT (p = 0.01, r= -0.4). The disease duration was negatively correlated with the scores on SPART-Immediate, SPART-Delayed and SDMT (p = 0.02, r= -0.4; p = 0.005, r= -0.4 and p = 0.05, r= -0.3).5-α-DHP may be lower even in well-controlled cases. 5-α-DHP may contribute to better perceptual processing and attention in cases with MS.

Faster progression to multiple sclerosis disability is linked to neuronal pathways associated with neurodegeneration: An ethnicity study

Although the causes of multiple sclerosis are largely unknown, genetic and environmental components play an important role. Geographic distribution, varying with latitude, reflects both genetic and environmental influences. We conducted a retrospective exploratory observational study to characterize the disability progression of 2396 Jewish patients with relapsing-remitting multiple sclerosis, followed at the Sheba Multiple Sclerosis Center, Tel-Aviv, Israel; 188 patients who originated in Iraq and 2207 patients who originated in northern Europe. Peripheral blood microarray gene expression analysis was performed in a subgroup of patients to identify molecular pathways associated with faster disability progression. During a follow-up period of 18.8 and 19.8 years, respectively, 51.6% of patients with an Iraqi origin progressed to moderate disability defined as expanded disability status scale (EDSS) score of 3.0 to 5.5, compared to 44.2% of patients with a northern European origin (odds ratio 1.347, 95% CI 1.0-1.815, p = 0.049). An Iraqi origin was associated with increased risk of progression to moderate disability adjusted for sex, disease duration, age at onset, and treatment with immunomodulatory drugs (hazard ratio 1.323; 95% CI, 1.049-1.668, p = 0.02), but not to severe disability defined as EDSS score > = 6.0 (i.e., walking aids are required for a distance of 100 meters, (hazard ratio 1.311; 95% CI, 0.918-1.874, p = 0.136). Gene expression analysis disclosed 98 differentially expressed genes (79 over-expressed and 19 under-expressed) between relapsing-remitting multiple sclerosis patients of Iraqi origin (N = 17) and northern European (N = 34) origin. Interestingly, this gene expression was enriched with genes related to neuronal pathways associated with morphology of axons, branching of neurites, proliferation of neocortical neurons, and formation of myelin sheath, suggesting an augmented process of neurodegeneration in relapsing-remitting multiple sclerosis patients with an Iraqi origin. The study results suggest that relapsing-remitting multiple sclerosis patients with an Iraqi origin progress faster to disability possibly due to an enhanced process of neurodegeneration.

Association of cognitive impairment and quality of life in patients with multiple sclerosis: A cross-sectional study

Background: Cognitive impairments in patients with multiple sclerosis (MS) are suggested as a prognostic factor for disease development, and consequently higher disability and more deficits in daily and social activities. In this regard, we aimed to investigate the association between quality of life (QOL) and cognitive function in patients with MS. Methods: We conducted a cross-sectional study on patients with relapsing-remitting MS (RRMS). General characteristic variables were carried out, and then all patients underwent assessments such as Multiple Sclerosis Quality of Life-54 (MSQOL-54), Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS), Expanded Disability Status Scale (EDSS), Beck Depression Inventory-II (BDI-II), and North American Adult Reading Test (NAART). Results: In the present study, a total of 92 patients, including 76 women with a mean disease duration of 6.82 ± 4.80 years were involved. Results of simple Pearson correlation revealed a significant positive relation between California Verbal Learning Test (CVLT) total learning with MSQOL mental health (r = 0.267, P = 0.017) and physical health (r = 0.299, P = 0.007). After adjusting for potential confounders, there was a negative correlation between MSQOL mental health with Delis-Kaplan Executive Function System (D-KEFS) (r = -0.303, P = 0.015) and Judgment of Line Orientation (JLO) (r = -0.310, P = 0.013). Besides, MSQOL physical health was negatively associated with Brief Visuospatial Memory Test-Revised (BVMT-R) in the adjusted model (r = -0.270, P = 0.031). Conclusion: There is a statistically significant association between specific aspects of cognitive decline and QOL. Therefore, more attention should be paid to cognitive impairment in patients with MS as based on our findings, it is significantly associated with QOL.

Validation of the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) in the Russian Population

OBJECTIVE

Cognitive dysfunction is common in multiple sclerosis (MS). The Brief International Cognitive Assessment for MS (BICAMS) battery of tests has been suggested as a measure for the evaluation of the cognitive status of MS patients. This study aims to validate the BICAMS battery in the Russian population of MS patients.

METHODS

Age- and sex-matched MS patients (n = 98) and healthy individuals (n = 86) were included in the study. Symbol Digit Modalities Test (SDMT), California Verbal Learning Test, 2nd edition (CVLT-II) and the Brief Visuospatial Memory Test - Revised (BVMT-R) were administered to all participants. The battery was readministered 1 month later to 44 MS patients to investigate the test-retest reliability.

RESULTS

MS patients exhibited a significantly lower performance in testing with BICAMS than the control group in all three neuropsychological tests. Test-retest reliability was good for SDMT and CVLT-II (r = .82 and r = .85, respectively) and adequate for BVMT-R (r = .70). Based on the proposed criterion for impairment as z score below 1.5 SD the mean of the control group, we found that 34/98 (35%) of MS patients were found impaired at least in one cognitive domain. Patients with Expanded Disability Status Scale score ≥3.5 performed significantly worse than controls (SDMT, p < .0001; CVLT-II, p = .03; BVMT-R, p = .0004), while those with ≤3.0 scores did not.

CONCLUSION

This study demonstrates that the BICAMS battery is a valid instrument to identify cognitive impairment in MS patients and it can be recommended for routine use in the Russian Federation.

Optical Coherence Tomography Is Associated With Cognitive Impairment in Multiple Sclerosis

BACKGROUND

Optical coherence tomography (OCT) is a sensitive method for quantifying retinal neuronal and axonal structures. Reductions in retinal nerve fiber layer (RNFL) and ganglion cell inner plexiform layer (GCIPL) thicknesses have a reported association with white and grey matter atrophy in multiple sclerosis (MS). We hypothesized that the thinning of intraretinal layer measurements associates with cognitive decline in MS patients with no prior event of optic neuritis (ON).

METHODS

OCT and NeuroTrax computerized cognitive assessments were performed in 204 relapsing remitting MS patients with no history of ON or other conditions affecting the eye. Data were collected between 2010 and 2020 and retrospectively analyzed. Correlations were examined between cognitive performance and a lower RNFL or GCIPL thickness. A multilinear regression model was generated to assess the significance of these correlations regarding the disability score and disease duration.

RESULTS

The 204 study participants had a mean age of 40.52 ± 11.8 years (mean ± SD) and disease duration of 9.80 ± 9.40 years. The mean RNFL thickness in this whole cohort was 82.22 ± 10.85 μm and the global cognitive score was 95.32 ± 12.32. The mean GCIPL thickness measured in a subgroup of 104 patients was 74.27 ± 10.37 μm. The RNFL and GCIPL both correlated with the global cognitive score (r = 0.174, P = 0.013 and r = 0.29, P = 0.03, respectively), and with various cognitive domains. However, the GCIPL showed stronger correlations than RNFL, particularly with executive function (r = 0.29, P = 0.003), attention (r = 0.332, P = 0.001), and the information processing speed (r = 0.25, P = 0.012). These correlations remained significant after correcting for confounders.

CONCLUSION

OCT measurements correlate with cognitive performance in MS patients. OCT can thus be used to evaluate central nervous system neurodegeneration in MS, as reflected by cognitive decline.

Assessing Cognitive Function in Multiple Sclerosis With Digital Tools: Observational Study

Background

Cognitive impairment (CI) is one of the most prevalent symptoms of multiple sclerosis (MS). However, it is difficult to include cognitive assessment as part of MS standard care since the comprehensive neuropsychological examinations are usually time-consuming and extensive.

Objective

To improve access to CI assessment, we evaluated the feasibility and potential assessment sensitivity of a tablet-based cognitive battery in patients with MS.

Methods

In total, 53 participants with MS (24 [45%] with CI and 29 [55%] without CI) and 24 non-MS participants were assessed with a tablet-based cognitive battery (Adaptive Cognitive Evaluation [ACE]) and standard cognitive measures, including the Symbol Digit Modalities Test (SDMT) and the Paced Auditory Serial Addition Test (PASAT). Associations between performance in ACE and the SDMT/PASAT were explored, with group comparisons to evaluate whether ACE modules can capture group-level differences.

Results

Correlations between performance in ACE and the SDMT (R=–0.57, P<.001), as well as PASAT (R=–0.39, P=.01), were observed. Compared to non-MS and non-CI MS groups, the CI MS group showed a slower reaction time (CI MS vs non-MS: P<.001; CI MS vs non-CI MS: P=.004) and a higher attention cost (CI MS vs non-MS: P=.02; CI MS vs non-CI MS: P<.001).

Conclusions

These results provide preliminary evidence that ACE, a tablet-based cognitive assessment battery, provides modules that could potentially serve as a digital cognitive assessment for people with MS.

Trial Registration

ClinicalTrials.gov NCT03569618; https://clinicaltrials.gov/ct2/show/NCT03569618

Targeted cognitive game training enhances cognitive performance in multiple sclerosis patients treated with interferon beta 1-a

Background

Prevention of cognitive decline in Multiple Sclerosis (MS) is of major importance. We explored the effect of a 6 months computerized game training program on cognitive performance in MS patients with mild cognitive impairment.

Methods

This was a single-center, randomized prospective study. We enrolled in this study 100 eligible MS patients treated with Interferon-beta-1a (Rebif). All had mild cognitive impairment in either executive function or information processing speed. Patients were randomized 1:1 to either use the cognitive games platform by HappyNeuron (HN) or receive no intervention. Executive function and information processing speed scores were measured at 3 and 6 months from baseline to evaluate the effect of game training on cognitive scores.

Results

In both executive function and information processing speed, the game Training group showed significant improvement after 3 and 6 months. The Non-Training group showed mild deterioration in both domains at 3 months, and further deterioration that became significant at 6 months in executive function. Furthermore, at 6 months, the percent of patients in the Training group that improved or remained stable in both cognitive domains was significantly higher compared to the Non-Training group.

Conclusions

Our findings suggest that cognitive game training has a beneficial effect on cognitive performance in MS patients suffering from mild cognitive impairment. While further evaluation is required to assess the longevity of that effect, we nonetheless recommend to MS patients to be engaged in cognitive gaming practice as part of a holistic approach to treating their condition.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12984-021-00968-3.

Cognitive and Neuroimaging Correlates of the Insomnia Severity Index in Obstructive Sleep Apnea: A Pilot-Study

We aim to determine the sleep correlates of age-related brain loss in a sample of middle-aged to older males with obstructive sleep apnea (OSA). We recruited consecutive treatment naïve male patients with moderate to severe OSA from January to November of 2019. We excluded participants if they had dementia, stroke or heart disease. We collected demographic variables and vascular risk factors. We also obtained the insomnia severity index, the Epworth sleepiness scale and the Pittsburgh sleep quality index. We also obtained computerized neurocognitive testing with the go-no-go response inhibition test, Stroop interference test, catch game test, staged information processing speed test, verbal memory test and non-verbal memory test. We derived age and education adjusted domain-specific Z-scores for global cognition, memory, attention, processing speed and executive function. We used brain MRI T1-weighted images to derive total hippocampal and gray matter volumes. Partial correlations evaluated associations between variables from sleep questionnaires (e.g., insomnia severity index score), and polysomnographic variables (the apnea-hypopnea index, average oxygen levels during sleep) with cognitive domains and brain volumes. We examined 16 participants with an age range of 40–76 years, 73% Hispanic/Latino. The mean apnea-hypopnea index was 48.9 ± 25.5 and average oxygen saturation during sleep was 91.4% ± 6.9%. Hypertension was seen in 66% and diabetes mellitus in 27%. We found that the insomnia severity index score and average oxygen levels during sleep had the strongest correlations with brain volumes and cognition. These preliminary findings may aid in developing future strategies to improve age-related brain loss in patients with OSA.

Parity and disability progression in relapsing-remitting multiple sclerosis

AIM

It is unclear whether parity and increasing parity are risk factors for long-term disability progression in relapsing-remitting multiple sclerosis. Furthermore, data on the effects of immunomodulatory treatments in this context are limited.

OBJECTIVES

To examine the association between parity and long-term neurological sequela among relapsing-remitting multiple sclerosis patients.

METHODS

A cohort study including all women with relapsing-remitting multiple sclerosis in Israel registered in Sheba Medical Center Multiple Sclerosis data registry from 1995 to 2018. The risks of progression to moderate and severe disability according to parity after disease onset were evaluated. Cox regression models using childbirth as a time-dependent covariate were used to study the association between parity and disability progression.

RESULTS

During the 26,785 person-years of follow-up a total of 2281 women were included in the study. Parity was associated with decreased risk of progression to moderate (adj.HR, 0.68; 95% CI 0.54-0.85, P = 0.001) but not to severe disability (adj.HR, 0.88; 95% CI 0.68-1.14, P = 0.36). Hazard ratios for progression to moderate and severe disability were comparable between women with one, two, and three or more births. In a subgroup analysis of women who gave birth within 5 years of disease onset, immunomodulatory treatment did not affect moderate or severe disability-free survival.

CONCLUSION

This study suggests that childbirth after the onset of multiple sclerosis is associated with a decreased risk of progression to moderate neurological disability.

Cognitive Impairment and Brain Reorganization in MS: Underlying Mechanisms and the Role of Neurorehabilitation

Multiple sclerosis (MS) is a chronic, immune-mediated, inflammatory, and degenerative disease of the central nervous system (CNS) that affects both white and gray matter. Various mechanisms throughout its course, mainly regarding gray matter lesions and brain atrophy, result in cognitive network dysfunction and can cause clinically significant cognitive impairment in roughly half the persons living with MS. Altered cognition is responsible for many negative aspects of patients' lives, independently of physical disability, such as higher unemployment and divorce rates, reduced social activities, and an overall decrease in quality of life. Despite its devastating impact it is not included in clinical ratings and decision making in the way it should be. It is interesting that only half the persons with MS exhibit cognitive dysfunction, as this implies that the other half remain cognitively intact. It appears that a dynamic balance between brain destruction and brain reorganization is taking place. This balance acts in favor of keeping brain systems functioning effectively, but this is not so in all cases, and the effect does not last forever. When these systems collapse, functional brain reorganization is not effective anymore, and clinically apparent impairments are evident. It is therefore important to reveal which factors could make provision for the subpopulation of patients in whom cognitive impairment occurs. Even if we manage to detect this subpopulation earlier, effective pharmaceutical treatments will still be lacking. Nevertheless, recent evidence shows that cognitive rehabilitation and neuromodulation, using non-invasive techniques such as transcranial magnetic or direct current stimulation, could be effective in cognitively impaired patients with MS. In this Mini Review, we discuss the mechanisms underlying cognitive impairment in MS. We also focus on mechanisms of reorganization of cognitive networks, which occur throughout the disease course. Finally, we review theoretical and practical issues of neurorehabilitation and neuromodulation for cognition in MS as well as factors that influence them and prevent them from being widely applied in clinical settings.