A cross-sectional and longitudinal study evaluating brain volumes, RNFL, and cognitive functions in MS patients and healthy controls

Effectiveness of anti-psychiatric treatment on visual and haptic perceptual disorder for a patient with Alzheimer’s disease: A case report

BACKGROUND

Perception is frequently impaired in patients with Alzheimer’s disease (AD). Several patients exhibit visual or haptic hallucinations.

CASE SUMMARY

A 71-year-old Chinese man presented with visual and haptic hallucinations he had been experiencing for 2 weeks. The clinical manifestations were the feeling of insects crawling and biting the limbs and geison. He looked for the insects while itching and scratching, which led to skin breakage on the limbs. He was treated with topical and anti-allergic drugs in several dermatology departments without any significant improvement. After admission, the patient was administered risperidone (0.5 mg) and duloxetine (2 mg/day). One week later, the dose of risperidone was increased to 2 mg/day, and that of duloxetine was increased to 60 mg/day. After 2 weeks of treatment, the patient’s sensation of insects crawling and biting disappeared, and his mood stabilized.

CONCLUSION

This patient manifested psychiatric behavioral symptoms caused by AD brain atrophy. It was important to re-evaluate the patient’s cognitive-psychological status when the patient repeatedly went to the hospital for treatment. Follow-up attention to cognitive function and the consideration of perceptual deficits as early manifestations of AD should be considered.

Cognitive performance and magnetic resonance imaging in people with multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

Several studies have shown the different relationships between cognitive functions and structural magnetic resonance imaging (MRI) measurements in people with multiple sclerosis (pwMS). However, there is an ongoing debate regarding the magnitude of correlation between MRI measurements and specific cognitive function tests. This systematic review and meta-analysis aimed to synthesize the most consistent correlations between MRI measurements and cognitive function in pwMS.

METHODS

PubMed/MEDLINE, Embase, Scopus, and Web of Science databases were systematically searched up to February 2023, to find relevant data. The search utilized syntax and medical subject headings (MeSH) relevant to cognitive performance tests and MRI measurements in pwMS. The R software version 4.3.3 with random effect models was used to estimate the pooled effect sizes.

RESULTS

13,559 studies were reviewed, of which 136 were included. The meta-analyses showed that thalamic volume had the most significant correlations with Symbol Digit Modalities Test (SDMT) r = 0.47 (95 % CI: 0.39 to 0.56, p < 0.001, I2 = 88 %), Brief Visual Memory Test-Revised-Total Recall (BVMT-TR) r = 0.51 (95 % CI: 0.36 to 0.66, p < 0.001, I2 = 81 %), California Verbal Learning Test-II-Total Recall (CVLT-TR) r = 0.47 (95 % CI: 0.34 to 0.59, p < 0.001, I2 = 69 %,), and Delis-Kaplan Executive Function System (DKEFS) r = 0.48 (95 % CI: 0.34 to 0.63, p < 0.001, I2 = 22 %,).

CONCLUSION

We conclude that thalamic volume exhibits highest relationships with information processing speed (IPS), visuospatial learning-memory, verbal learning-memory, and executive function in pwMS. A comprehensive understanding of the intricacies of the mechanisms underpinning this association requires additional research.

Correlation between cognitive changes and neuroradiological changes over time in multiple sclerosis: a systematic review and meta-analysis

BACKGROUND

While many studies have examined relationships of neuroimaging variables to cognitive measures in multiple sclerosis (MS), longitudinal studies are lacking. The relationship of cognitive changes to neuroradiological changes in MS is thus incompletely understood. The present study systematically reviews all studies reporting a relationship between MRI changes and cognitive changes after at least one year of follow-up.

METHOD

An extensive and methodical search of online databases was conducted to identify qualified studies until August 2023. Among various cognitive tests and magnetic resonance imaging (MRI) measures, Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT), verbal fluency, T2 lesion volume (T2LV), white matter lesion volume (WML), and grey matter volume (GMV) qualified for inclusion in a meta-analysis investigating the association of cognitive changes to neuroradiological changes.

RESULTS

We identified 35 studies that explored the link between MRI changes and changes in cognitive outcomes. Of these, twenty studies (57.14%) investigated the association between SDMT/PASAT and MRI metrics. Eleven studies (31.42%) focused on the relationship between MRI metrics and verbal learning and memory, while ten studies (28.57%) reported associations with visuospatial learning and memory. Furthermore, eight studies (22.85%) analyzed the correlation between verbal fluency and MRI measures. Only 5 were eligible for inclusion in the meta-analysis. The meta-analysis evaluated correlations between SDMT/PASAT and GMV (rs = 0.67, 95% CI 0.44-0.91), and verbal fluency and T2LV (rs = 0.35, 95% CI 0.09-0.60).

CONCLUSION

In this rigorously conducted systematic review, we found a significant association of cognitive changes, specifically SDMT/PASAT and verbal fluency, to changes in T2LV and atrophy in individuals with MS. Findings should be interpreted cautiously due to the limited amount of high-quality research, small sample sizes, and variability in study methodologies.

Diagnosis of multiple sclerosis using optical coherence tomography supported by explainable artificial intelligence

BACKGROUND/OBJECTIVES

Study of retinal structure based on optical coherence tomography (OCT) data can facilitate early diagnosis of relapsing-remitting multiple sclerosis (RRMS). Although artificial intelligence can provide highly reliable diagnoses, the results obtained must be explainable.

SUBJECTS/METHODS

The study included 79 recently diagnosed RRMS patients and 69 age matched healthy control subjects. Thickness (Avg) and inter-eye difference (Diff) features are obtained in 4 retinal layers using the posterior pole protocol. Each layer is divided into six analysis zones. The Support Vector Machine plus Recursive Feature Elimination with Leave-One-Out Cross Validation (SVM-RFE-LOOCV) approach is used to find the subset of features that reduces dimensionality and optimises the performance of the classifier.

RESULTS

SVM-RFE-LOOCV was used to identify OCT features with greatest capacity for early diagnosis, determining the area of the papillomacular bundle to be the most influential. A correlation was observed between loss of layer thickness and increase in functional disability. There was also greater functional deterioration in patients with greater asymmetry between left and right eyes. The classifier based on the top-ranked features obtained sensitivity = 0.86 and specificity = 0.90.

CONCLUSIONS

There was consistency between the features identified as relevant by the SVM-RFE-LOOCV approach and the retinotopic distribution of the retinal nerve fibres and the optic nerve head. This simple method contributes to implementation of an assisted diagnosis system and its accuracy exceeds that achieved with magnetic resonance imaging of the central nervous system, the current gold standard. This paper provides novel insights into RRMS affectation of the neuroretina.

Optical coherence tomography as a potential surrogate marker of dopaminergic modulation across the life span

The retina has been considered a "window to the brain" and shares similar innervation by the dopaminergic system with the cortex in terms of an unequal distribution of D1 and D2 receptors. Here, we provide a comprehensive overview that Optical Coherence Tomography (OCT), a non-invasive imaging technique, which provides an "in vivo" representation of the retina, shows promise to be used as a surrogate marker of dopaminergic neuromodulation in cognition. Overall, most evidence supports reduced retinal thickness in individuals with dopaminergic dysregulation (e.g., patients with Parkinson's Disease, non-demented older adults) and with poor cognitive functioning. By using the theoretical framework of metacontrol, we derive hypotheses that retinal thinning associated to decreased dopamine (DA) levels affecting D1 families, might lead to a decrease in the signal-to-noise ratio (SNR) affecting cognitive persistence (depending on D1-modulated DA activity) but not cognitive flexibility (depending on D2-modulated DA activity). We argue that the use of OCT parameters might not only be an insightful for cognitive neuroscience research, but also a potentially effective tool for individualized medicine with a focus on cognition. As our society progressively ages in the forthcoming years and decades, the preservation of cognitive abilities and promoting healthy aging will hold of crucial significance. OCT has the potential to function as a swift, non-invasive, and economical method for promptly recognizing individuals with a heightened vulnerability to cognitive deterioration throughout all stages of life.

Interactions of optic radiation lesions with retinal and brain atrophy in early multiple sclerosis

OBJECTIVE

Retrograde trans-synaptic neuroaxonal degeneration is considered a key pathological factor of subclinical retinal neuroaxonal damage in multiple sclerosis (MS). We aim to evaluate the longitudinal association of optic radiation (OR) lesion activity with retinal neuroaxonal damage and its role in correlations between retinal and brain atrophy in people with clinically isolated syndrome and early MS (pweMS).

METHODS

Eighty-five pweMS were retrospectively screened from a prospective cohort (Berlin CIS cohort). Participants underwent 3T magnetic resonance imaging (MRI) for OR lesion volume and brain atrophy measurements and optical coherence tomography (OCT) for retinal layer thickness measurements. All pweMS were followed with serial OCT and MRI over a median follow-up of 2.9 (interquartile range: 2.6-3.4) years. Eyes with a history of optic neuritis prior to study enrollment were excluded. Linear mixed models were used to analyze the association of retinal layer thinning with changes in OR lesion volume and brain atrophy.

RESULTS

Macular ganglion cell-inner plexiform layer (GCIPL) thinning was more pronounced in pweMS with OR lesion volume increase during follow-up compared to those without (Difference: -0.82 μm [95% CI:-1.49 to -0.15], p = 0.018). Furthermore, GCIPL thinning correlated with both OR lesion volume increase (β [95% CI] = -0.27 [-0.50 to -0.03], p = 0.028) and brain atrophy (β [95% CI] = 0.47 [0.25 to 0.70], p < 0.001). Correlations of GCIPL changes with brain atrophy did not differ between pweMS with or without OR lesion increase (η p 2  = 5.92e-7 , p = 0.762).

INTERPRETATION

Faster GCIPL thinning rate is associated with increased OR lesion load. Our results support the value of GCIPL as a sensitive biomarker reflecting both posterior visual pathway pathology and global brain neurodegeneration.

The Evolvement of OCT and OCT-A in Identifying Multiple Sclerosis Biomarkers

The prevalence of multiple sclerosis (MS) has been increasing among young people in developing countries over the last years. With the continuous development of new technology, the diagnosis and follow-up of these patients has received new parameters that physicians may use in their practice. This paper reviews the main biomarkers identified through Optical Coherence Tomography Angiography (OCT-A) involved in the development and progression of MS and investigates the role it may have in detecting changes to the central nervous system (CNS).

Optical coherence tomography (OCT) measurements and cognitive performance in multiple sclerosis: a systematic review and meta-analysis

BACKGROUND

Several studies report mixed associations between the retinal nerve fiber layer (RNFL) thickness with cognitive and physical disability in persons with multiple sclerosis (PwMS). Systematic synthesis of these findings is crucial in deriving credible conclusions.

METHODS

Five databases were searched from their inception to March 2022. The inclusion criteria for studies were MS-specific and required RNFL and cognitive performance data in order to be analyzed. The selection processes followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

The systematic review yielded 31 studies that investigated the association between RNFL thickness and cognitive performance. Twenty-two studies reported positive associations, and nine did not. The meta-analysis included 11 studies with a total of 782 PwMS with mean age of 40.5 years, mean Expanded Disability Status Scale (EDSS) of 2.7, and disease duration of 11.3 years. RNFL thickness was significantly associated Symbol Digit Modalities Test (pooled r = 0.306, p < 0.001), Paced Auditory Serial Addition Test (pooled r = 0.374, p < 0.001) and Word List Generation (WLG, pooled r = 0.177, p < 0.001). RNFL was also significantly correlated with visuospatial learning and memory tests (pooled r = 0.148, p = 0.042) and verbal learning and memory tests (pooled r = 0.245, p = 0.005). Within three eligible studies, no significant association between ganglion cell inner-plexiform layer and SDMT 0.083 (95% CI - 0.186, 0.352) was noted. The heterogeneity was high in all correlation studies (I² > 63% and p < 0.008) except for the WLG and visuospatial memory findings.

CONCLUSION

RNFL thickness is associated with cognitive processing speed, verbal learning and memory, visual learning and memory, as well as verbal fluency in PwMS. The number of studies included in the meta-analyses were limited due to non-standardized reporting.

The relationship between retinal layer thickness and cognition in patients with multiple sclerosis: A systematic review of current literature

Background: This study was conducted to evaluate the relationship between retinal layer thickness (RLT) and cognition in patients with multiple sclerosis (MS). Methods: We searched PubMed, Scopus, Embase, Web of Science, and Google Scholar. The search strategy included the MeSH and text words as ["ora serrata" OR "retina" OR ("coherence tomography" AND "optical") OR "OCT tomography" OR (tomography AND OCT) OR "optical coherence tomography" OR "OCT" OR "retinal thickness" OR "inner plexiform layer" OR "nerve fiber layer" OR "ganglion cell layer" OR "inner nuclear layer" OR "outer plexiform layer" OR "outer nuclear layer" OR "external limiting membrane" OR "inner segment layer" OR "outer segment layer" OR "retinal pigment epithelium"] AND ["cognition"* OR "cognitive function"* OR (function* AND cognitive)] AND [(sclerosis AND multiple) OR (sclerosis AND disseminated) OR "disseminated sclerosis" OR "multiple sclerosis" OR "acute fulminating"]. Results: The literature search revealed 1090 articles; after deleting duplicates, 980 remained. Finally, 14 studies were included. Totally, 1081 patients were evaluated. Mean age ranged from 31 to 55 years. In some studies, there was a correlation between cognition and retinal thickness, while others did not confirm this finding. Some authors found cognitive impairment (CI) in patients with MS with RLT. Conclusion: The results of this systematic review show that there are discrepancies between the results of studies regarding the relationship between RLT and cognition status in patients with MS. Further studies with more included original studies and meta-analysis are recommended.

The correlation of retinal neurodegeneration and brain degeneration in patients with Alzheimer's disease using optical coherence tomography angiography and MRI

Introduction

Pathological changes in Alzheimer's disease can cause retina and optic nerve degeneration. The retinal changes are correlated with cognitive function. This study aimed to explore the relationship of retinal differences with neuroimaging in patients with Alzheimer's disease, analyze the association of cognitive function with retinal structure and vascular density, and identify potential additional biomarkers for early diagnosis of Alzheimer's disease.

Method

We performed magnetic resonance imaging (MRI) scans and neuropsychological assessments in 28 patients with mild Alzheimer's disease and 28 healthy controls. Retinal structure and vascular density were evaluated by optical coherence tomography angiography (OCTA). Furthermore, we analyzed the correlation between neuroimaging and OCTA parameters in patients with mild Alzheimer's disease with adjustment for age, gender, years of education, and hypertension.

Results

In patients with mild Alzheimer's disease, OCTA-detected retinal parameters were not significantly correlated with MRI-detected neuroimaging parameters after Bonferroni correction for multiple testing. Under multivariable analysis controlled for age, gender, years of education, and hypertension, the S-Hemi (0-3) sector of macular thickness was significantly associated with Mini-cog (β = 0.583, P = 0.002) with Bonferroni-corrected threshold at P < 0.003.

Conclusion

Our findings suggested decreased macular thickness might be associated with cognitive function in mild AD patients. However, the differences in retinal parameters didn't correspond to MRI-detected parameters in this study. Whether OCTA can be used as a new detection method mirroring MRI for evaluating the effect of neuronal degeneration in patients with mild Alzheimer's disease still needs to be investigated by more rigorous and larger studies in the future.

Relation between retina, cognition and brain volumes in MS: a consequence of asymptomatic optic nerve lesions

INTRODUCTION

Asymptomatic optic nerve lesions are frequent in multiple sclerosis (MS) and their impact on cognition and/or brain volume has never been taken into account.

PATIENTS AND METHODS

We used the data from the cross-sectional Visual Ways in MS (VWIMS) study including relapsing remitting MS. All patients underwent brain and optic nerve Magnetic Resonance Imaging (MRI) including Double Inversion Recuperation (DIR) sequence, retinal OCT, and cognitive evaluation with the Brief International Cognitive Assessment in MS (BICAMS). We measured the association between OCT findings (thickness/volume of retinal layers) and extra-visual parameters (cerebral volumes and BICAMS scores) in optic nerves with and/or without the presence of DIR asymptomatic optic nerve hypersignal.

RESULTS

Between March and December 2017, we included 98 patients. Two patients were excluded. Over the 192 eyes, 73 had at least one clinical history of optic neuritis (ON-eyes) whereas 119 were asymptomatic (NON-eyes). Among the 119 NON-eyes, 58 had 3D-DIR optic nerve hypersignal (48.7%). We confirmed significant associations between some retinal OCT measures and some extra-visual parameters (cerebral volumes, cognitive scores) in NON-eyes. Unexpectedly, these associations were found when an asymptomatic optic nerve DIR-hypersignal was present on MRI, but not when it was absent.

CONCLUSION

Our study showed a relation between OCT measures and extra-visual parameters in NON-eyes MS patients. As a confusion factor, asymptomatic optic nerve lesions may be the explanation of the relation between OCT measures and extra-visual parameters. Retinal OCT seems to be far more a "window over the optic nerve" than a "window over the brain".

Serum and CSF Biomarkers Predict Active Early Cognitive Decline Rather Than Established Cognitive Impairment at the Moment of RRMS Diagnosis

(1) Background: Cognitive impairment (CI) begins early in the evolution of multiple sclerosis (MS) but may only become obvious in the later stages of the disease. Little data is available regarding predictive biomarkers for early, active cognitive decline in relapse remitting MS (RRMS) patients. (2) Methods: 50 RRMS patients in the first 6 months following diagnosis were included. The minimum follow-up was one year. Biomarker samples were collected at baseline, 3-, 6- and 12-month follow-up. Cognitive performance was assessed at baseline and 12-month follow-up; (3) Results: Statistically significant differences were found for patients undergoing active cognitive decline for sNfL z-scores at baseline and 3 months, CSF NfL baseline values, CSF Aβ42 and the Bremso score as well. The logistic regression model based on these 5 variables was statistically significant, χ2(4) = 22.335, p < 0.0001, R2 = 0.671, with a sensitivity of 57.1%, specificity of 97.4%, a positive predictive value of 80% and a negative predictive value of 92.6%. (4) Conclusions: Our study shows that serum biomarkers (adjusted sNfL z-scores at baseline and 3 months) and CSF biomarkers (CSF NfL baseline values, CSF Aβ42), combined with a clinical score (BREMSO), can accurately predict an early cognitive decline for RRMS patients at the moment of diagnosis.

Choroidal Thickness in Multiple Sclerosis: An Optical Coherence Tomography Study

Background and Purpose

To identify changes in the choroidal thickness (CT) in multiple sclerosis (MS) patients with and without optic neuritis (ON) using enhanced-depth-imaging optical coherence tomography (EDI-OCT).

Methods

This cross-sectional study included 96 eyes with MS and 28 eyes of healthy controls. All participants underwent an ophthalmologic examination and EDI-OCT scanning (Spectralis, Heidelberg Engineering, Germany) to assess the CT and the retinal nerve fiber layer (RNFL) thickness. MS patients were divided into two groups: 1) with and 2) without a history of ON. The CT was evaluated in the fovea and at six horizontal and six vertical points at 500, 1,000, and 1,500 µm from the fovea. Paired t-tests were used to compare the groups, and p-value<0.05 was considered as significant.

Results

At all 13 measurements points, the CT was thicker in MS patients than in the healthy controls and was thinner in eyes with ON than in the contralateral eyes, but these differences were not statistically significant. However, the CT was always larger in all points in eyes with a history of ON than in the control eyes. The RNFL was significantly thinner (p<0.05) in both MS and ON eyes than in the control eyes.

Conclusions

The CT did not differ between MS and control eyes, but it was significantly larger in patients with a history of ON, in whom the RNFL was thinner. Further studies are necessary to establish the possible role of the choroid in MS.

Spectral-domain OCT measurements in obesity: A systematic review and meta-analysis

Background

Previous studies proposed possible applications of spectral-domain optical coherence tomography (SD-OCT) measurements in prognosticating pathologies observed in overweight/obesity, including ocular, vascular, and neurologic consequences. Therefore, we conducted a systematic review and meta-analysis to investigate the changes in the in SD-OCT measurements of the patients with higher body mass index (BMI) compared to normal weight individuals.

Materials and methods

We conducted a systematic search on PubMed, Scopus, and Embase. The search results underwent two-phase title/abstract and full-text screenings. We then analyzed SD-OCT measurements differences in patients with high BMI and controls, and performed meta-regression, sub-group analysis, quality assessment, and publication bias assessment. The measurements included macular thickness, cup to disc ratio, ganglion cell-inner plexiform layer (GC-IPL) and its sub-sectors, RNFL and peripapillary RNFL (pRNFL) and their sub-layers, and choroidal thickness and its sub-sectors.

Results

19 studies were included in this meta-analysis accounting for 1813 individuals, 989 cases and 824 controls. There was an overall trend towards decreased thickness in high BMI patients, but only two measurements reached statistical significance: temporal retinal nerve fiber layer (RNFL) (Standardized mean difference (SMD): -0.33, 95% confidence interval (CI): -0.53 to -0.14, p<0.01) and the choroidal region 1.0 mm nasal to fovea (SMD: -0.38, 95% CI: -0.60 to -0.16, p<0.01).

Conclusion

Some ocular layers are thinner in patients with higher BMI than the controls. These SD-OCT measurements might correlate with adverse events related to increased body weight and have prognostic abilities. As SD-OCT is a robust, rapid and non-invasive tool, future guidelines and studies are needed to evaluate the possibility of their integration into care of the patients with obesity.

Connection between microstructural alterations detected by diffusion MRI and cognitive dysfunction in MS: A model-free analysis approach

BACKGROUND

Cognitive decline is a prominent symptom of MS. Clear connection between cognitive status and white matter microstructural changes has not been unequivocally observed to date.

OBJECTIVE

To characterise the relationship between white matter microstructure and cognitive performance a partial least squares (PLS) approach was used.

METHODS

53 RR MS patients' T1 and DTI images and BICAMS subtests were used in our analysis. Standard FSL pipeline was used to obtain diffusion parameters. A PLS approach was applied to reveal the diffusion parameter patterns responsible for the cognitive dysfunction.

RESULTS

The first latent variable (LV) was mainly associated with demyelination, while the second and third explained axonal damage. While the first two LV represented mainly Brief Visuospatial Memory Test (BVMT) and Single Digit Modality Test (SDMT), the third LV depicted diffusion alterations mainly the verbal subtest. The first LVs spatial map showed demyelination in the corpus callosum. The second LVs spatial map showed the diffusion alterations in the thalamus. The third LV depicted diffusion alterations in the putative left superior longitudinal fascicle.

CONCLUSION

Visual memory demanding tasks versus language functions depend on distinct patterns of diffusion parameters and the spatial organisation. Axial diffusivity alterations, a putative marker of irreversible axonal loss explained around 20% of variability in the cognitive functions.

Optical coherence tomography in multiple sclerosis: A 3-year prospective multicenter study

Objective

To evaluate changes over 3 years in the thickness of inner retinal layers including the peripapillary retinal nerve fiber layer (pRNFL), and combined macular ganglion cell and inner plexiform layers (mGCIPL), in individuals with relapsing‐remitting multiple sclerosis (RRMS) versus healthy controls; to determine whether optical coherence tomography (OCT) is sufficiently sensitive and reproducible to detect small degrees of neuroaxonal loss over time that correlate with changes in brain volume and disability progression as measured by the Expanded Disability Status Scale (EDSS).

Methods

Individuals with RRMS from 28 centers (n = 333) were matched with 64 healthy participants. OCT scans were performed on Heidelberg Spectralis machines (at baseline; 1 month; 6 months; 6‐monthly thereafter).

Results

OCT measurements were highly reproducible between baseline and 1 month (intraclass correlation coefficient >0.98). Significant inner retinal layer thinning was observed in individuals with multiple sclerosis (MS) compared with controls regardless of previous MS‐associated optic neuritis––group differences (95% CI) over 3 years: pRNFL: −1.86 (−2.54, −1.17) µm; mGCIPL: −2.03 (−2.78, −1.28) µm (both p < 0.0001; effect sizes 0.39 and 0.34). Greater inner retinal layer atrophy was observed in individuals diagnosed with RRMS <3 years versus >5 years (pRNFL: p < 0.05; mGCIPL: p < 0.01). Brain volume decreased by 1.3% in individuals with MS over 3 years compared to 0.5% in control subjects (effect size 0.76). mGCIPL atrophy correlated with brain atrophy (p < 0.0001). There was no correlation of OCT data with disability progression.

Interpretation

OCT has potential to estimate rates of neurodegeneration in the retina and brain. The effect size for OCT, smaller than for magnetic resonance imaging based on Heidelberg Spectralis data acquired in this study, was increased in early disease.

Cognitive Decline in Multiple Sclerosis Is Related to the Progression of Retinal Atrophy and Presence of Oligoclonal Bands: A 5-Year Follow-Up Study

Background: Brain atrophy, which is associated with cognitive impairment and retinal nerve fiber layer (RNFL) atrophy, is the main biomarker of neurodegeneration in multiple sclerosis (MS). However, data on the relationship between inflammatory markers, such as oligoclonal bands (OCBs) in the cerebrospinal fluid (CSF), and cognition, RNFL atrophy, and brain atrophy are scarce. The aim of this study was to assess the influence of RNFL thickness, brain atrophy markers, intrathecal OCBs, and the immunoglobulin G (IgG) index on cognitive decline over a 5-year period in patients with MS. Methods: This prospective, single-center, observational cohort study included 49 patients with relapsing MS followed up over 5 years. At baseline, the patients underwent brain magnetic resonance imaging (MRI). Cognitive evaluation was performed using the Brief International Cognitive Assessment for MS (BICAMS), and RNFL thickness was assessed using optical coherence tomography (OCT). OCBs and IgG levels in the CSF were evaluated at baseline. The BICAMS, OCT, and MRI findings were re-evaluated after 5 years. Results: A significant reduction in information processing speed, visual learning, temporal RNFL thickness, the Huckman index, and third ventricle mean diameter was found in all 49 patients with relapsing MS over the observation period (p < 0.05). Of the patients, 63.3% had positive OCBs and 59.2% had elevated IgG indices. The atrophy of the temporal segment and papillomacular bundle and the presence of OCBs were significantly related to a decline in information processing speed in these patients (p < 0.05). However, brain atrophy markers were not found to be significant on the general linear models. Conclusions: RNFL atrophy and the presence of OCBs were related to cognitive decline in patients with MS over a 5-year follow-up period, thereby suggesting their utility as potential biomarkers of cognitive decline in MS.

Association of Retinal Layer Thickness With Cognition in Patients With Multiple Sclerosis

Objective

Retinal layer thickness (RLT) measured by optical coherence tomography (OCT) is considered a noninvasive, cost-efficient marker of neurodegeneration in multiple sclerosis (MS). We aimed to investigate associations of RLT with cognitive performance and its potential as indicator of cognitive status in patients with MS by performing generalized estimating equation (GEE) analyses.

Methods

In this cross-sectional study, patients with at least mild signs of cognitive impairment were examined by OCT as well as by the Brief International Cognitive Assessment for MS and tests assessing attention and executive functions (Trail Making Test [TMT] A and B). Associations of these factors were investigated using GEE models controlling for demographic and disease-related factors and correcting for multiple testing.

Results

A total of 64 patients entered the study. In the final sample (n = 50 [n = 14 excluded due to missing data or drop-outs]; n = 44 relapsing-remitting MS and n = 6 secondary progressive MS, mean Expanded Disability Status Scale score = 2.59 [SD = 1.17], disease duration [median] = 7.34 [interquartile range = 12.1]), 36.0% were cognitively impaired. RLT of the macular retinal nerve fiber layer was associated with performance in TMT-B (β = −0.259). Analyses focusing on the upper and lower tertile of RLT additionally revealed associations between macular ganglion cell-inner plexiform layer and TMT-B and verbal short-term memory and learning, respectively.

Conclusion

In patients with MS, at less advanced disease stages, RLT was especially associated with cognitive flexibility promoting OCT as a potential marker advocating further extensive neuropsychological examination.

Progressive Loss of Corneal and Retinal Nerve Fibers in Patients With Multiple Sclerosis: A 2-Year Follow-up Study

Purpose

To determine longitudinal alterations in corneal nerve fiber morphology, dendritic cell (DC) density, and retinal nerve fiber layer (RNFL) thickness over 2 years in patients with multiple sclerosis (MS).

Methods

Thirty-one consecutive patients with relapsing-remitting MS (RRMS) underwent assessment of the Kurtzke Expanded Disability Status Scale (EDSS), Multiple Sclerosis Severity Score (MSSS), corneal confocal microscopy to quantify corneal subbasal nerve morphology and DC density, and spectral-domain optical coherence tomography to quantify RNFL thickness at baseline and after 2 years.

Results

There was a significant reduction in corneal nerve fiber area (CNFA) (P = 0.003), nerve fiber width (CNFW) (P = 0.005), and RNFL thickness (P = 0.004) with an increase in EDSS (P = 0.01) over 2 years. The change in corneal nerve fiber density (CNFD) correlated with the change in EDSS (ρ = -0.468; P = 0.008), MSSS (ρ = -0.442; P = 0.01), DC density (ρ = -0.550; P = 0.001), and RNFL (ρ = 0.472; P = 0.007). The change in corneal nerve fiber length (CNFL) correlated with the change in EDSS (ρ = -0.445; P = 0.01) and MSSS (ρ = -0.490; P = 0.005). Furthermore, there was a significant decrease in CNFL (P < 0.001), CNFA (P = 0.02), CNFW (P = 0.04), corneal total branch density (P = 0.01), and RNFL thickness (P = 0.02) and a significant increase in DC density (P = 0.04) in patients with worsening EDSS (n = 15).

Conclusions

Corneal confocal microscopy can be used to detect progressive corneal nerve fiber loss that relates to a progression of disability in patients with RRMS.

Translational Relevance

Corneal confocal microscopy acts as a sensitive imaging biomarker for progressive nerve degeneration in patients with MS.

A two-year longitudinal follow-up of cognitive performance assessed by BICAMS in newly diagnosed patients with MS

BACKGROUND

Cognitive impairment is common in patients with multiple sclerosis (MS) and may occur at any stage and with any subtype of the disease. Screening and monitoring of cognitive function should therefore be implemented into everyday clinical neurology practice. The Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) was developed for this purpose. Although several cross-sectional studies have validated BICAMS, longitudinal studies evaluating its use as part of a clinical follow-up routine are still lacking.

OBJECTIVE

To investigate cognitive function and trajectories of change assessed by the BICAMS test battery in a cohort of newly diagnosed relapsing-remitting MS (RRMS) patients examined at baseline and after 12 and 24 months.

METHODS

BICAMS was used to assess cognitive function in 58 RRMS patients, who also filled in the Hospital Anxiety and Depression Scale (HADS) and the Fatigue Scale for Motor and Cognitive Functions (FSMC), and underwent standard neurological evaluations at baseline and at the two follow-ups.

RESULTS

A total of 27 patients (46.6%) were defined as cognitively impaired at baseline on at least one test, and 22 (37.9%) were defined as impaired at follow-up after 24 months. Throughout the study, 8 (13.8%) and 4 (6.9%) patients were consistently defined as impaired on two or three tests, respectively. The mean raw scores on two BICAMS subtests (SDMT and CVLT-II) improved significantly from baseline to the first follow-up, and then remained stable the next year, whereas the visual memory test (BVMT-R) were overall unchanged from baseline to the end of the study. The correlations between the scores on HADS, FSMC and the BICAMS subtests were non-significant at baseline, but weak to moderate negative correlations were found at the one- and two-year follow-ups.

CONCLUSION

The patients showed improved test results from baseline to the first follow-up examination, indicating that an effect of previous practise should be taken into account when interpreting the results. With results showing both trajectories of stability and change, our study supported the validity of including BICAMS as part of a clinical follow-up routine of RRMS patients. Anxiety, depression, fatigue and cognition should always be assessed at the same time to reveal interaction effects that are expected to affect the daily-life functioning of at least some of the RRMS patients.

Correlations between retinal nerve fiber layer thickness and cognitive progression in Parkinson's disease: A longitudinal study

BACKGROUND

Retinal abnormalities measured by optical coherence tomography (OCT) have been detected in both Parkinson's disease (PD) and Alzheimer's disease (AD). Cognitive impairment is not only found in AD, but 75-90% of PD patients will also develop dementia in the late stage of disease. We assessed whether baseline retinal nerve fiber layer (RNFL) thickness predicted worsening of cognitive status over time and the correlation between RNFL thickness and the detailed impaired cognitive domains in PD.

METHODS

RNFL thickness was measured using high-definition OCT in 78 non-dementia PD patients. Clinical and cognitive assessments were performed at baseline and at 3.61 ± 0.65 years follow-up. Linear mixed-effects models were used to examine associations between RNFL thickness and the changes in cognitive test scores, after adjusting for age, sex, disease duration and education.

RESULTS

Analysis of outcomes according to baseline RNFL tertiles showed worse performance in global cognitive tests, delayed memory, and executive functions in patients with a thin RNFL. During follow-up, greater cognitive deterioration was found in thin RNFL tertile patients. Lower baseline average RNFL thickness was associated with greater annualized decline in Mini-Mental State Examination and Montreal Cognitive Assessment.

CONCLUSION

The correlation between RNFL thickness and cognitive dysfunction suggests that OCT may be useful for predicting cognitive dysfunction in PD patients.

Retinal Levels of Amyloid Beta Correlate with Cerebral Levels of Amyloid Beta in Young APPswe/PS1dE9 Transgenic Mice before Onset of Alzheimer's Disease

Objectives

Retina abnormalities are related to cognitive disorders in patients with Alzheimer's disease (AD). Retinal amyloid beta (Aβ) can be labeled by curcumin. We measured Aβ content in the cerebrum and retina of APPswe/PS1dE9 (APP) transgenic mice with early age to investigate the correlation between cerebrum and retina.

Methods

APP mice and age-matched wild-type mice were investigated every month from age 2 months to 6 months to assess changes in Aβ content in the retina and cerebrum. At the beginning of each month, mice were fed a curcumin diet (50 mg/kg/day) for 7 consecutive days. The Aβ levels in the retina and cerebrum were measured by ELISAs. Correlations were identified between retinal and cerebral Aβ contents using Pearson's correlation.

Results

In the absence of curcumin, there was a significant correlation between Aβ contents in the retina and cerebrum of APP mice (r = 0.7291, P = 0.0014). With increasing age, Aβ-mediated degenerative change in the cerebrum (P < 0.001 in 5 months) and retina (P < 0.01 in 5 months) increased significantly. The inhibitory effect of curcumin on the Aβ level was significant in the cerebrum (P < 0.001) and retina (P < 0.01) of older APP mice in the early stage of life.

Conclusion

We observed a significant correlation between the Aβ content in the retina and Aβ content in the cerebrum of APP mice. Our data suggest an appropriate time to measure retinal Aβ. Although curcumin can label Aβ in the retina, it also suppresses Aβ levels and weakens the degree of correlation between Aβ in cerebrum and retina tissues.

Transbulbar B-mode sonography in multiple sclerosis without optic neuritis; clinical relevance

OBJECTIVE

Trans bulbar B-mode sonography (TBS) is a recently proposed method but there is little known about its diagnostic accuracy in patients with multiple sclerosis without acute optic neuritis. Therefore we assessed the correlation between OND, ONSD and OND/ONSD ratio with clinical/para clinical parameters.

METHODS

In a comparative study, we intended to examine possible differences in optic nerve diameter (OND) and optic nerve sheath diameter (ONSD) between 60 patients with multiple sclerosis (MS) and 60 individuals as matched healthy controls.

RESULTS

The OND, ONSD and OND/ONSD ratio in both eyes showed significantly lower amounts in patients compared to healthy controls (p < 0.05). There were no correlations, between either OND or ONSD and factors including gender, age, P100 amplitude, disease duration, history of optic neuritis and number of T2 lesions in MRI (P ≥ 0.05). Expanded disability status scale (EDSS) and p100 Latency were correlated with both OND and ONSD values (P < 0.05).

CONCLUSIONS

TBS showed significantly lower amounts of OND, ONSD and OND/ONSD ratio in MS patients without current attack compared to their healthy controls indicating a subclinical axonal loss over time. It is suggested that TBS could be an applicable tool for early detection of optic nerve damages along with clinical and para-clinical findings.

Retinal Nerve Fiber Layer Thickness Decrease in Obesity as a Marker of Neurodegeneration

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a serious condition that is frequently associated with irreversibly vision loss, having a higher incidence among obese women. Our aims were to screen subclinical IIH in obese patients scheduled to bariatric surgery using peripapillary retinal nerve fiber layer (RNFL) thickness and to evaluate if the findings demand the possible need of a preoperative evaluation in this population.

METHODS

This study included 111 eyes from 36 obese patients (86% female, body mass index > 35 kg/m²) scheduled to bariatric surgery and 20 non-obese (body mass index < 25 kg/m²) age-matched controls. We measured sectorial and mean RNFL thickness in a 3.5-mm-diameter circular scan centered on the optic nerve head, using optical coherence tomography (Heidelberg Spectralis SD-OCT) in all participants. Multivariate linear regression was used for adjustments.

RESULTS

No patient had subclinical IIH corresponding to increased RNFL thickness. However, in obese individuals, global peripapillary RNFL was thinner than in controls (104 ± 6 μm versus 99 ± 12 μm, p = 0.005). Overall, RNFL thickness was superior in the control group for all sectors. The differences reached significance for the nasal, temporal, superior temporal, and inferior temporal sectors. These differences remained even after adjusting for possible confounders (hypertension, dyslipidemia, diabetes, age, sleep apnea syndrome, and sex).

CONCLUSIONS

Routine screening asymptomatic obese patients undergoing bariatric surgery for IIH using RNFL thickness was not clinically relevant in our study. However, we found that severe obesity is associated with neurodegeneration independently of the other components of the metabolic syndrome, what may justify future investigation on the need of monitoring these patients.

In MS: Immunosuppression is passé

IMPORTANCE

Prolonged and significant alterations of the immune system by immunosuppression makes multiple sclerosis (MS) patients susceptible to opportunistic infections and malignancies over long periods of treatment.

OBSERVATIONS

A reasonable clinical and practical definition of immunosuppression is a temporary or permanent alteration of the body's immune system and subsequent lack of ability to fight infections and malignancies. Immunosurveillance is the sine qua non of the immune system. Immunosurveillance is the constant process by which the immune system looks for and recognizes foreign pathogens such as bacteria and viruses or pre-cancerous or cancerous cells in the body. Immunomodulation (a decrease or increase in pitch or tone - in this case a decrease) maintains immunosurveillance. Immunosuppression (quashing, stamping out) impedes immunosurveillance by one mechanism or another. Immunosuppressive agents need to be administered continually in order to maintain effectiveness. In contrast, immune reconstitution therapies (IRTs) are short course agents that are initially immunosuppressive but ultimately immunomodulatory and can provide significant decreased disease activity over time without retreatment.

CONCLUSIONS AND RELEVANCE

The goal of disease modifying therapies in MS is effectiveness over long periods of time with minimal risk. The preservation, reduction or elimination of immunosurveillance should be an important consideration in deciding on the optimal disease modifying treatments (DMT) for an individual MS patient. IRTs have the advantage of providing long term control of disease activity with short term immunosuppression followed by long term immunomodulation without retreatment. For most MS patients with mild or modest disease activity, initial immunomodulation followed by IRT for breakthrough disease may be the best option. In MS, immunosuppression may be passé.

Early detection of cognitive dysfunction in patients with multiple sclerosis: Implications on outcome

Objective:

Cognitive impairment in multiple sclerosis (MS) has a complex relationship with disease progression and neurodegeneration. The aim of this study was to shed light on the importance of early detection of cognitive impairment in MS patients.

Methods:

The study comprised two groups of definite MS patients, relapsing remitting multiple sclerosis (RRMS) and secondary progressive multiple sclerosis (SPMS), each with 25 patients. Physical disability was assessed using the Expanded Disability Status Scale (EDSS), while the risk of secondary progression was assessed using the Bayesian Risk Estimate for Multiple Sclerosis (BREMS). Cognitive functions were assessed using the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) and Controlled Oral Word Association Test (COWAT). Assessment of neurodegeneration was done using optical coherence tomography (OCT) via quantification of retinal nerve fiber layer (RNFL).

Results:

MS patients with higher RNFL thickness demonstrated a larger learning effect size than patients who had lower values in RNFL thickness regardless of MS type. RRMS patients showed significant improvement in delayed recall after giving cues than SPMS. The symbol digit modalities test was the only neuropsychological test that showed a significant negative correlation with EDSS (P = 0.009). There was a statistically significant negative correlation between BREMS scores and performance in all neuropsychological tests.

Conclusion:

Inclusion of neurocognitive evaluation in the periodic assessment of MS patients is mandatory to detect patients at increased risk of secondary progression. The thickness of RNFL is suggested as a method to estimate the expected benefit of cognitive rehabilitation, regardless of MS type.