Low-frequency MR elastography reveals altered deep gray matter viscoelasticity in multiple sclerosis.

INTRODUCTION: Brain viscoelasticity as assessed by magnetic resonance elastography (MRE) has been discussed as a promising surrogate of microstructural alterations due to neurodegenerative processes. Existing studies indicate that multiple sclerosis (MS) is associated with a global reduction in brain stiffness. However, no study to date systematically investigated the MS-related characteristics of brain viscoelasticity separately in normal-appearing white matter (NAWM), deep gray matter (DGM) and T2-hyperintense white matter (WM) lesions. METHODS: 70 MS patients and 42 healthy volunteers underwent whole-cerebral MRE using a stimulated echo sequence (DENSE) with a low-frequency mechanical excitation at 20 Hertz. The magnitude |G∗| (Pa) and phase angle φ (rad) of the complex shear modulus G∗ were reconstructed by multifrequency dual elasto-visco (MDEV) inversion and related to structural imaging and clinical parameters. RESULTS: We observed φ in the thalamus to be higher by 4.3 % in patients relative to healthy controls (1.11 ± 0.07 vs. 1.06 ± 0.07, p < 0.0001). Higher Expanded Disability Status Scale (EDSS) scores were negatively associated with φ in the basal ganglia (p = 0.01). We measured φ to be lower in MS lesions compared to surrounding NAWM (p = 0.001), which was most prominent for lesions in the temporal lobe (1.01 ± 0.22 vs. 1.06 ± 0.19, p = 0.003). Age was associated with lower values of |G∗| (p = 0.04) and φ (p = 0.004) in the thalamus of patients. No alteration in NAWM stiffness relative to WM in healthy controls was observed. CONCLUSION: Low-frequency elastography in MS patients reveals age-independent alterations in the viscoelasticity of deep gray matter at early stages of disease.

Evaluation of a self-administered iPad®-based processing speed assessment for people with multiple sclerosis in a clinical routine setting.

BACKGROUND: Limited resources often hinder regular cognitive assessment of people with multiple sclerosis (pwMS) in standard clinical care. A self-administered iPad®-based cognitive screening-tool (Processing Speed Test; PST) might mitigate this problem. OBJECTIVE: To evaluate the PST in clinical routine. METHODS: We investigated the feasibility of the PST in both a quiet and a waiting room setting. We assessed the validity of the PST in comparison with the established Symbol Digit Modalities Test (SDMT). We explored associations between processing speed assessments and the Brief International Cognitive Assessment for MS (BICAMS), magnetic resonance imaging (MRI) parameters, and psychological factors. Additionally, we explored the ability of the PST to detect impairment in processing speed compared to the SDMT. RESULTS: The PST was feasible in the waiting room setting. PST and SDMT correlated comparably with the BICAMS, MRI parameters, and psychological variables. Of 172 pwMS, 50 (30.8%) showed cognitive impairment according to the BICAMS; respective values were 47 (27.3%) for the SDMT and 9 (5.2%) for the PST. CONCLUSIONS: The PST performed in a waiting room setting correlates strongly with established cognitive tests. It thus may be used to assess processing speed in a resource-efficient manner and complement cognitive assessment in clinical routine. Despite comparable validity of the PST and SDMT, we identified more pwMS with impaired processing speed using normative data of the SDMT compared to the PST and advise caution, that the common cut-off score of - 1.5 SD from the current PST is not appropriate in Europe.

Psychological factors and brain magnetic resonance imaging metrics associated with fatigue in persons with multiple sclerosis.

BACKGROUND: Besides demographics and clinical factors, psychological variables and brain-tissue changes have been associated with fatigue in persons with multiple sclerosis (pwMS). Identifying predictors of fatigue could help to improve therapeutic approaches for pwMS. Therefore, we investigated predictors of fatigue using a multifactorial approach. METHODS: 136 pwMS and 49 normal controls (NC) underwent clinical, neuropsychological, and magnetic resonance imaging examinations. We assessed fatigue using the "Fatigue Scale for Motor and Cognitive Functions", yielding a total, motor, and cognitive fatigue score. We further analyzed global and subcortical brain volumes, white matter lesions and microstructural changes (examining fractional anisotropy; FA) along the cortico striatal thalamo cortical (CSTC) loop. Potential demographic, clinical, psychological, and magnetic resonance imaging predictors of total, motor, and cognitive fatigue were explored using multifactorial linear regression models. RESULTS: 53% of pwMS and 20% of NC demonstrated fatigue. Besides demographics and clinical data, total fatigue in pwMS was predicted by higher levels of depression and reduced microstructural tissue integrity in the CSTC loop (adjusted R2 = 0.52, p < 0.001). More specifically, motor fatigue was predicted by lower education, female sex, higher physical disability, higher levels of depression, and self-efficacy (adjusted R2 = 0.54, p < 0.001). Cognitive fatigue was also predicted by higher levels of depression and lower self-efficacy, but in addition by FA reductions in the CSTC loop (adjusted R2 = 0.45, p < 0.001). CONCLUSIONS: Our results indicate that depression and self-efficacy strongly predict fatigue in MS. Incremental variance in total and cognitive fatigue was explained by microstructural changes along the CSTC loop, beyond demographics, clinical, and psychological variables.

Immune profiling in multiple sclerosis: a single-center study of 65 cytokines, chemokines, and related molecules in cerebrospinal fluid and serum.

Introduction: The understanding of the pathophysiology of multiple sclerosis (MS) has evolved alongside the characterization of cytokines and chemokines in cerebrospinal fluid (CSF) and serum. However, the complex interplay of pro- and anti-inflammatory cytokines and chemokines in different body fluids in people with MS (pwMS) and their association with disease progression is still not well understood and needs further investigation. Therefore, the aim of this study was to profile a total of 65 cytokines, chemokines, and related molecules in paired serum and CSF samples of pwMS at disease onset. Methods: Multiplex bead-based assays were performed and baseline routine laboratory diagnostics, magnetic resonance imaging (MRI), and clinical characteristics were assessed. Of 44 participants included, 40 had a relapsing-remitting disease course and four a primary progressive MS. Results: There were 29 cytokines and chemokines that were significantly higher in CSF and 15 in serum. Statistically significant associations with moderate effect sizes were found for 34 of 65 analytes with sex, age, CSF, and MRI parameters and disease progression. Discussion: In conclusion, this study provides data on the distribution of 65 different cytokines, chemokines, and related molecules in CSF and serum in newly diagnosed pwMS.

Kappa free light chain and neurofilament light independently predict early multiple sclerosis disease activity-a cohort study.

BACKGROUND: Inter-individual courses of multiple sclerosis (MS) are extremely variable. The objective of this study was to investigate whether κ-free light chain (κ-FLC) index and serum neurofilament light (sNfL) have an additive predictive value for MS disease activity. METHODS: Patients with early MS who had cerebrospinal fluid (CSF) and serum sampling at disease onset were followed for four years. At baseline, age, sex, disease duration, number of T2-hyperintense (T2L), and contrast-enhancing T1 lesions (CEL) on MRI were determined. During follow-up, the occurrence of a second clinical attack and start of disease-modifying treatment (DMT) were registered. κ-FLC was measured by nephelometry, and κ-FLC index calculated as [CSF κ-FLC/serum κ-FLC]/albumin quotient. sNfL was determined by single-molecule array, and age- and body-mass-index adjusted Z scores were calculated. FINDINGS: A total of 86 patients at a mean age of 33 ± 10 years and with a female predominance of 67% were included; 36 (42%) patients experienced a second clinical attack during follow-up. Cox regression analysis adjusted for age, sex, T2L, CEL, disease and follow-up duration, and DMT use during follow-up revealed that both κ-FLC index as well as sNfL Z score independently predict time to second clinical attack. The chance for freedom of relapse within 12 months was 2% in patients with high levels of κ-FLC index (>100) and high sNfL Z score (>3), 30% in patients with high κ-FLC index (>100) and lower sNfL Z score (≤3), 70% in patients with lower κ-FLC index (≤100) but high sNfL Z score (>3), and 90% in patients with lower levels of κ-FLC index (≤100) and sNfL Z score (≤3). INTERPRETATION: κ-FLC index and sNfL Z score have an additive predictive value for early MS disease activity that is independent of known predictors. FUNDING: This study was funded by a grant of the charitable foundation of the Austrian Multiple Sclerosis Society.

Olfactory threshold predicts treatment response in relapsing multiple sclerosis.

BACKGROUND: Olfactory threshold (OT) is associated with short-term inflammatory activity in relapsing multiple sclerosis (RMS). OBJECTIVE: We aimed to investigate OT for prediction of treatment response in RMS. METHODS: In this 5-year prospective study on 123 RMS patients, OT was measured at disease-modifying treatment (DMT) initiation (M0), after 3 months (M3), and 12 months (M12) by Sniffin' Sticks test. Primary endpoint was defined as an absence of relapse during the observation period, with Expanded Disability Status Scale (EDSS) progression and magnetic resonance imaging (MRI) activity being the secondary endpoints. Optimal cutoff values were determined by receiver operating characteristic analyses and their predictive value assessed by multivariable Cox regression models. RESULTS: Higher OT scores at M0, M3, and M12 were independently associated with decreased relapse probability with the strongest risk reduction at M3 (hazard ratio (HR) = 0.44, p < 0.001). Improvement of OT scores from M0 to M3 (ΔOTM3) was also associated with reduced relapse risk (HR = 0.12, p < 0.001). OT score > 6.5 at M3 was the strongest predictor of relapse freedom (HR = 0.10, p < 0.001) with high diagnostic accuracy (positive predictive value (PPV) = 87%), closely followed by ΔOTM3 ⩾ 0.5 (HR = 0.12, p < 0.001, PPV = 86%). CONCLUSIONS: OT is an independent predictor of freedom of disease activity upon DMT initiation within 5 years and may be a useful biomarker of treatment response.

Experiences in treatment of multiple sclerosis with natalizumab from a real-life cohort over 15 years.

Natalizumab (NTZ) has been used for treatment of highly active relapsing-remitting multiple sclerosis (MS). When stopping NTZ the risk of severe rebound phenomenon has to be considered. We aimed to investigate the use of NTZ in clinical routine and focused on identification of potential risk factors for disease reactivation after treatment discontinuation. At the Medical University of Innsbruck, Austria, we identified all MS patients who were treated with NTZ and performed a retrospective analysis on therapeutic decision making, disease course before, during and after treatment with NTZ and on risk factors for disease reactivation after NTZ discontinuation. 235 NTZ treated MS patients were included, of whom 105 had discontinued treatment. At NTZ start disease duration was 5.09 (IQR 2.09-10.57) years, average number of total relapses was 4 (IQR 3-6) and median EDSS 2.0 (range 0-6.5), whereby these values significantly decreased over time. Reduction of annualized relapse rate (ARR) on treatment was 93% and EDSS remained stable in 64%. In multivariate regression models only conversion to secondary progressive MS (SPMS) on treatment was significantly associated with lower risk of disease reactivation after NTZ, while ARR before treatment was associated with earlier disease reactivation. We could confirm the high therapeutic efficacy of NTZ which trends to be used earlier in the disease course nowadays. Discontinuation of NTZ seems safe only in patients who convert to SPMS during treatment, while higher ARR before NTZ increases the risk of disease reactivation after treatment discontinuation.

Kappa-Free Light Chains in CSF Predict Early Multiple Sclerosis Disease Activity.

OBJECTIVE: To investigate whether κ-free light chain (κ-FLC) index predicts multiple sclerosis (MS) disease activity independent of demographics, clinical characteristics, and MRI findings. METHODS: Patients with early MS who had CSF and serum sampling at disease onset were followed for 4 years. At baseline, age, sex, type of symptoms, corticosteroid treatment, and number of T2 hyperintense (T2L) and contrast-enhancing T1 lesions (CELs) on MRI were determined. During follow-up, the occurrence of a second clinical attack and start of disease-modifying therapy (DMT) were registered. κ-FLCs were measured by nephelometry, and κ-FLC index calculated as [CSF κ-FLC/serum κ-FLC]/albumin quotient. RESULTS: A total of 88 patients at a mean age of 33 ± 10 years and female predominance of 68% were included; 38 (43%) patients experienced a second clinical attack during follow-up. In multivariate Cox regression analysis adjusting for age, sex, T2L, CEL, disease and follow-up duration, administration of corticosteroids at baseline and DMT during follow-up revealed that κ-FLC index predicts time to second clinical attack. Patients with κ-FLC index >100 (median value 147) at baseline had a twice as high probability for a second clinical attack within 12 months than patients with low κ-FLC index (median 28); within 24 months, the chance in patients with high κ-FLC index was 4 times as high as in patients with low κ-FLC index. The median time to second attack was 11 months in patients with high κ-FLC index whereas 36 months in those with low κ-FLC index. CONCLUSION: High κ-FLC index predicts early MS disease activity. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in patients with early MS, high κ-FLC index is an independent risk factor for early second clinical attack.

Retinal layer thinning predicts treatment failure in relapsing multiple sclerosis.

BACKGROUND AND PURPOSE: Peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell plus inner plexiform layer (GCIPL) thinning are markers of neuroaxonal degeneration in multiple sclerosis (MS), which is reduced by disease-modifying treatment (DMT). We aimed to investigate the potential of pRNFL and GCIPL thinning for prediction of DMT failure in relapsing MS (RMS). METHODS: In this 4-year prospective observational study on 113 RMS patients, pRNFL and GCIPL were measured at DMT initiation and after 12 months (M12) and 24 months (M24). Treatment failure was defined as 6-month confirmed Expanded Disability Status Scale (EDSS) progression and/or Symbol Digit Modalities Test (SDMT) worsening. Optimal cutoff values for predicting treatment failure were determined by receiver operating characteristic analyses and hazard ratios (HRs) by multivariable Cox regression adjusting for age, sex, disease duration, EDSS/SDMT, and DMT class. RESULTS: Thinning of GCIPL >0.5 µm/year at M24 showed superior value for treatment failure prediction (HR: 4.5, 95% confidence interval [CI]: 1.8-7.6, p < 0.001; specificity 91%, sensitivity 81%), followed by GCIPL >0.5 µm at M12 (odds ratio [OR]: 3.9, 95% CI: 1.4-6.9, p < 0.001; specificity 85%, sensitivity 78%), and pRNFL ≥2 µm/year at M24 (OR: 3.7, 95% CI: 1.1-6.5, p = 0.023; specificity 84%, sensitivity 69%), whereas pRNFL at M12 was not predictive. CONCLUSIONS: GCIPL, and to a lesser degree pRNFL, thinning predicts disability progression after DMT initiation and may be a useful and accessible biomarker of treatment failure in RMS.

Macular ganglion cell-inner plexiform layer thinning as a biomarker of disability progression in relapsing multiple sclerosis.

BACKGROUND: Macular ganglion cell-inner plexiform layer (mGCIPL) is an emerging biomarker of neuroaxonal degeneration in multiple sclerosis (MS). OBJECTIVE: We aimed to determine cut-off values of mGCIPL thinning for discriminating between progressing and stable patients in relapsing multiple sclerosis (RMS). METHODS: This is a 3-year prospective longitudinal study on 183 RMS patients with annual optical coherence tomography. Best possible cut-off values of baseline mGCIPL and annual loss of macular ganglion cell-inner plexiform layer (aLmGCIPL) for discriminating clinically progressing (physical progression or cognitive decline) from stable patients were defined by receiver operating characteristics analysis and tested using multivariate regression models. RESULTS: Baseline mGCIPL thickness <77 µm was associated with an increased risk (hazard ratio: 2.7, 95% confidence interval (CI): 1.5-4.7, p < 0.001) of disability progression. An aLmGCIPL cut-off ⩾1 µm accurately identified clinically progressing patients (87% sensitivity at 90% specificity) and was a strong predictor of clinical progression (odds ratio: 18.3, 95% CI: 8.8-50.3). CONCLUSION: We present evidence that cross-sectionally measured mGCIPL thickness and annualized thinning rates of mGCIPL are able to identify clinically progressing RMS with high accuracy.

Quantifying the risk of disease reactivation after interferon and glatiramer acetate discontinuation in multiple sclerosis: The VIAADISC score.

BACKGROUND AND PURPOSE: There is a lack of evidence guiding discontinuation of disease-modifying therapy (DMT) in relapsing multiple sclerosis (RMS). Thus, the objective of this study was to generate and validate a risk score for disease reactivation after DMT discontinuation in RMS. METHODS: We drew a generation and validation dataset from two separate prospectively collected observational databases including RMS patients who received interferon-ß or glatiramer acetate for ≥12 months, then discontinued DMT for ≥6 months and had ≥2 years of follow-up available. In the generation sample (n = 168), regression analysis was performed to identify clinical or magnetic resonance imaging (MRI) variables independently predicting disease reactivation after DMT discontinuation. A predictive score was calculated using the variables included in the multivariable model and applied to the validation sample (n = 98). RESULTS: The variables included in the final model as independent predictors of disease reactivation were age at discontinuation, MRI activity at discontinuation, and duration of clinical stability (all p < 0.001). The resulting score was able to robustly identify patients at high (83%-85%), moderate (36%-38%), and low risk (7%) of disease reactivation within 5 years after DMT discontinuation in both cohorts. CONCLUSIONS: The composite VIAADISC score is a valuable tool to inform and support patients and neurologists in the process of decision making to discontinue injectable DMTs.

Retinal layer thinning is reflecting disability progression independent of relapse activity in multiple sclerosis.

BACKGROUND: PIRA (progression independent of relapse) has emerged as a term to quantify the proportion of disability worsening due to non-inflammatory neurodegenerative processes in multiple sclerosis (MS). OBJECTIVE: To determine the impact of PIRA on retinal thinning, a biomarker of neuroaxonal degeneration in MS, in comparison to traditional disability worsening and relapse. METHODS: In a 4-year, prospective observational study including 171 relapsing MS (RMS) patients, retinal thinning was determined by annual spectral-domain optical coherence tomography measuring macular ganglion-cell-and-inner-plexiform-layer (GCIPL) and peripapillary-retinal-nerve-fibre-layer (pRNFL). PIRA was defined as an expanded disability status scale (EDSS) or symbol digit modalities test (SDMT) worsening confirmed after 24 weeks with no relapse in the 30 days before or after the disability worsening. RESULTS: Each PIRA event was associated with a mean additional loss of GCIPL (1.8 µm) and pRNFL (1.9 µm), similar to the impact of EDSS and SDMT worsening. Overall relapse and relapse without subsequent EDSS worsening did not influence retinal thinning, while a relapse with EDSS worsening was associated with an additional loss of GCIPL (1.3 µm) and pRNFL (1.4 µm). CONCLUSIONS: PIRA is associated with retinal thinning, likely reflecting neurodegenerative processes, not directly associated with focal inflammation. It might be a clinical measure to identify MS patients with ongoing MS-associated neurodegeneration.

Transverse myelitis as a rare presentation of antiphospholipid-antibody-associated disorders.

We report the case of a 35-year-old male patient suffering from a clinical and radiological manifestation of a transverse myelitis associated with antiphospholipid antibodies. After a challenging diagnosis the patient improved substantially due to immunosuppressive treatment. The demyelinating spinal cord lesion and the impressive therapeutic outcome may support the possibility of a direct binding of antiphospholipid antibodies to CNS antigens and consequently leading to a neuroimmunological pathomechanism distinct from the well-known pro-thrombotic effect of antiphospholipid antibodies. In terms of clinical routine diagnostic this case report highlights a rare but notable differential diagnosis of Multiple Sclerosis-like syndromes.

Influence of physical activity on serum vitamin D levels in people with multiple sclerosis.

In most cases, multiple sclerosis (MS) patients reduce physical activity with disease progression and many patients are found to be vitamin D deficient. The aim of this study was to explore correlations between daily physical activity in everyday life and 25-hydroxyvitamin-D3 (25(OH)D3) serum levels in mildly disabled patients with an Expanded Disability Status Scale (EDSS) ≤ 4. We analyzed serum 25(OH)D3 levels and recorded daily physical activity (activity duration, number of steps, distance, energy expenditure) using an activity tracker for 14-days in 25 women and 15 men. Participants recorded their daily sunlight exposure time by diary during the study period. We found a positive correlation between physical activity and 25(OH)D3 levels in both, Pearson correlation (r = 0.221) and multivariate regression analysis (ß = 0.236), which was stronger than correlation with sunlight exposure time (ß = -0.081). EDSS and physical activity were weakly correlated (r = -0.228), but no correlation between EDSS and 25(OH)D3 levels was found (r = -0.077). There were no relevant differences in physical activity (p = 0.803) and 25(OH)D3 concentrations (p = 0.385) between the EDSS groups 0 - 1.5 and 2.0 - 4.0. In conclusion, physical activity has an effect on vitamin D levels independent of sunlight exposure time in people with MS (pwMS) with low-grade disability.

Late-onset neutropenia in a multiple sclerosis patient after first dose ocrelizumab switched from rituximab.

Ocrelizumab is a humanized monoclonal anti-CD20 antibody approved for treatment of relapsing-remitting and primary progressive multiple sclerosis (MS). Before approval of this drug, the chimeric anti-CD20 antibody rituximab was used off-label for treatment of MS. On treatment with rituximab late-onset neutropenia (LON) was reported as a rare adverse event. Here we report the case of a patient with MS who first received rituximab without experiencing any hematologic abnormalities, but developed grade IV LON after switching to ocrelizumab. This first case of LON in a patient treated with different anti-CD20 antibodies highlights the necessity of regular hemogram examinations during ocrelizumab.

To treat or not to treat: Sequential individualized treatment evaluation in relapsing multiple sclerosis.

BACKGROUND: The frequency and long-term prognosis of relapsing multiple sclerosis (RMS) never receiving disease-modifying treatment (DMT) is unclear. METHODS: We included 1186 RMS patients with a mean of 17.4 years follow-up and divided them into patients treated with any DMT (DMT) and patients untreated by shared (USD) or patient-autonomous decision (UAD). RESULTS: The USD group displayed features, which significantly differed from the two other groups: higher age at onset, mainly sensory onset symptoms, complete remission of onset symptoms, less T2 and contrast-enhancing T1 lesions on initial brain MRI. In a multivariate cox regression, USD was associated with lower risk for secondary progression (SPMS) conversion (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.55-0.97, p = 0.011) compared to DMT, while UAD was associated with an increased SPMS conversion risk only in the "McDonald era" (HR 1.19, CI 1.02-1.58, p = 0.028). CONCLUSION: Apart from the doubtless substantial improvement of the overall prognosis of RMS by DMT, it seems likely that not every patient necessarily needs immediate or even "hard and early" treatment. A "watchful waiting" approach with continuous clinical evaluation might be instead a viable option in RMS patients with favorable prognostic features at onset.

Pregnancy and multiple sclerosis in the DMT era: A cohort study in Western Austria.

BACKGROUND: Multiple sclerosis (MS) predominantly affects women of child-bearing potential. Pregnancy in MS is still a controversial issue lacking standardized treatment recommendations. OBJECTIVE: To examine the reciprocal effects of pregnancy, MS, and disease-modifying treatment (DMT). METHODS: We analyzed 387 pregnancies in 239 women with relapsing remitting multiple sclerosis (RRMS) and ⩾1 pregnancy, establishment of diagnosis >1 year before conception, and ⩾2 years of follow-up after delivery. Relapse rates and Expanded Disability Status Scale (EDSS) scores were compared in the year before conception, during pregnancy, and 2 years postpartum. Binary logistic regression was used to investigate predictors of risk for relapses and disability progression during pregnancy and postpartum. RESULTS: Risk of relapse and disability progression during pregnancy was predicted by pre-conception relapse activity, higher EDSS score at conception, use of highly effective disease-modifying treatment (H-DMT) pre-conception, and prolonged washout period. Postpartum relapse and disability progression was associated with relapse activity pre-conception and during pregnancy and use of H-DMT pre-conception. Early restart of DMT reduced the risk of postpartum relapse. CONCLUSION: A personalized approach in planning pregnancy in women with MS while on H-DMT needs to be adopted. It seems reasonable maintaining natalizumab closer to conception and restarting the drug early postpartum to reduce the considerable risk of disease reactivation during early pregnancy and after delivery.

Impairment of odor discrimination and identification is associated with disability progression and gray matter atrophy of the olfactory system in MS.

BACKGROUND: Impairment of odor discrimination (D), identification (I), and threshold (T) are characteristic features of multiple sclerosis (MS). OBJECTIVE: To identify patterns of gray matter concentration (GMC) associated with different qualities of olfactory function. METHODS: Olfactory function (T and combined DI score) was measured by Sniffin' Sticks-Test over 2 years longitudinally, and T1-weighted 3-T magnetic resonance imaging (MRI) was performed in 37 MS patients and 18 matched healthy controls (HCs). Statistical parametric mapping (SPM) was applied to objectively identify changes of voxel-wise-GMC throughout the entire brain volume and to correlate image parameters with odor function. RESULTS: SPM localized significant GMC decreases in the anterior cingulum as well as temporomesial and frontobasal brain areas of the MS group compared with HCs, and revealed significant correlations between lower DI scores and GMC decreases in the olfactory gyrus, anterior cingulum, temporal regions including the parahippocampus, and putamen. Contrarily, no correlations were found between T and GMC. Patients with disability progression had significantly lower mean temporomesial/putamen GMC (0.782 vs 0.804, p = 0.004) compared to patients without Expanded Disability Status Scale (EDSS) progression. CONCLUSION: Impairment of DI, but not T is associated with GM atrophy in brain regions related to olfactory function. Further studies are warranted to investigate DI scores and temporomesial/putamen GMC as biomarkers for disability progression.

Serum neurofilament levels correlate with retinal nerve fiber layer thinning in multiple sclerosis.

BACKGROUND: Serum neurofilament light chain (sNfL) levels and peripapillary retinal nerve fiber layer (pRNFL) are both emerging biomarkers of neuro-axonal damage in multiple sclerosis (MS). However, data on the relation between sNfL and pRNFL are scarce. OBJECTIVE: We aimed to determine the relation of sNfL levels with pRNFL thinning in a large cohort of relapsing-remitting (RR) MS patients. METHODS: We identified 80 patients from a prospective, 3-year observational study on retinal changes in RRMS with annual blood samples available. sNfL levels were measured using single-molecule array (SimoaTM) assay. Annualized loss of pRNFL (aLpRNFL) was determined by individual linear regression models. Correlations between single and repeated sNfL levels and aLpRNFL were analyzed using multivariate linear regression and mixed-effect models. RESULTS: After correction for sex, age, and baseline sNfL, an sNfL increase of 10 pg/mL was associated with an aLpRNFL of -0.7 µm (95% confidence interval (CI): (-1.3, -0.2), p < 0.001). Patients with ⩾2 sNfL measurements >75th percentile displayed higher aLpRNFL (2.2 µm, standard deviation (SD) 0.6) compared to patients with no sNfL measure >75th percentile (0.4 µm, SD 0.2, p < 0.001). Between 15% and 20% of the aLpRNFL variance could be predicted from sNfL levels. CONCLUSION: sNfL levels contribute to the prediction of retinal thinning in patients with RRMS, strengthening its value as a biomarker of neuro-axonal damage.

Smelling multiple sclerosis: Different qualities of olfactory function reflect either inflammatory activity or neurodegeneration.

BACKGROUND: Peripapillary retinal nerve fiber layer (pRNFL) thickness and olfactory function are both emerging biomarkers in multiple sclerosis (MS). Impairment of odor identification and discrimination is an irreversible feature of more advanced MS suggested to be associated with neurodegeneration, while olfactory threshold is a transient feature of early, active MS possibly associated with short-term inflammatory disease activity. OBJECTIVE: The aim of this study was to validate the association of olfactory (dys)function and parameters of MS disease course in a large cohort of MS patients and to correlate olfactory function with pRNFL thickness as a surrogate biomarker of neurodegeneration. METHODS: In a cross-sectional design, olfactory function was assessed using the Sniffin' Sticks test, which quantifies three different qualities of olfactory function (threshold, discrimination, and identification). pRNFL thickness was measured by spectral-domain optical coherence tomography (OCT). Results were correlated with age, sex, disease duration, relapses, Expanded Disability Status Scale (EDSS), cognitive function, depression, smoking, and pRNFL thickness by multivariable linear regression models. RESULTS: We included 260 MS patients (mean age of 35.9 years, 68.7% female). Olfactory threshold correlated significantly with number of relapses in the year prior to assessment and shorter disease duration. Odor discrimination, identification, and their sum score were significantly correlated with longer disease duration, higher EDSS, and reduced cognitive function. pRNFL thickness was associated with identification and discrimination, but not with threshold. CONCLUSION: Olfactory threshold is a marker of short-term inflammatory relapse activity unrelated to parameters of neurodegeneration, while odor identification and discrimination are markers of neurodegeneration mostly independent of relapse activity. Assessment of olfactory function provides an opportunity to stratify MS patients with regard to inflammation and neurodegeneration.