Cognition in patients with myelin oligodendrocyte glycoprotein antibody-associated disease: a prospective, longitudinal, multicentre study of 113 patients (CogniMOG-Study).

BACKGROUND: Data on cognition in patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are limited to studies with small sample sizes. Therefore, we aimed to analyse the extent, characteristics and the longitudinal course of potential cognitive deficits in patients with MOGAD. METHODS: The CogniMOG-Study is a prospective, longitudinal and multicentre observational study of 113 patients with MOGAD. Individual cognitive performance was assessed using the Paced Auditory Serial Addition Task (PASAT), the Symbol Digit Modalities Test (SDMT) and the Multiple Sclerosis Inventory Cognition (MuSIC), which are standardised against normative data from healthy controls. Cognitive performance was assessed at baseline and at 1-year and 2-year follow-up assessments. Multiple linear regression was used to analyse demographic and clinical predictors of cognitive deficits identified in previous correlation analyses. RESULTS: At baseline, the study sample of MOGAD patients showed impaired standardised performance on MuSIC semantic fluency (mean=-0.29, 95% CI (-0.47 to -0.12)) and MuSIC congruent speed (mean=-0.73, 95% CI (-1.23 to -0.23)). Around 1 in 10 patients showed deficits in two or more cognitive measures (11%). No decline in cognition was observed during the 1-year and 2-year follow-up period. Cerebral lesions were found to be negatively predictive for SDMT (B=-8.85, 95% CI (-13.57 to -4.14)) and MuSIC semantic fluency (B=-4.17, 95% CI (-6.10 to -2.25)) test performance. CONCLUSIONS: Based on these data, we conclude that MOGAD patients show reduced visuomotor processing speed and semantic fluency to the extent that the disease burden includes cerebral lesions.

Cognition in patients with neuromyelitis optica spectrum disorders: A prospective multicentre study of 217 patients (CogniNMO-Study).

BACKGROUND: There is limited and inconsistent information on the prevalence of cognitive impairment in neuromyelitis optica spectrum disorders (NMOSD). OBJECTIVE: To assess cognitive performance and changes over time in NMOSD. METHODS: This study included data from 217 aquaporin-4-IgG-seropositive (80%) and double-seronegative NMOSD patients. Cognitive functions measured by Symbol Digit Modalities Test (SDMT), Paced Auditory Serial-Addition Task (PASAT), and/or Multiple Sclerosis Inventory Cognition (MuSIC) were standardized against normative data (N = 157). Intraindividual cognitive performance at 1- and 2-year follow-up was analyzed. Cognitive test scores were correlated with demographic and clinical variables and assessed with a multiple linear regression model. RESULTS: NMOSD patients were impaired in SDMT (p = 0.007), MuSIC semantic fluency (p < 0.001), and MuSIC congruent speed (p < 0.001). No significant cognitive deterioration was found at follow-up. SDMT scores were related to motor and visual disability (pBon < 0.05). No differences were found between aquaporin-4-IgG-seropositive and double-seronegative NMOSD. CONCLUSIONS: A subset of NMOSD patients shows impairment in visual processing speed and in semantic fluency regardless of serostatus, without noticeable changes during a 2-year observation period. Neuropsychological measurements should be adapted to physical and visual disabilities.

[Public health situation of CIDP patients in nine German centers-neuritis network Germany]. / Versorgungssituation von CIDP-Patienten in neun deutschen Zentren des Neuritis Netzes.

BACKGROUND: Diagnosis and treatment of patients with immune-mediated neuropathies is challenging due to the heterogeneity of the diseases. OBJECTIVES: To assess similarities and differences in the current care of patients with immune-mediated polyneuropathies in specialized centers in Germany within the German neuritis network "Neuritis Netz". MATERIAL AND METHODS: We conducted a cross-sectional survey of nine neurological departments in Germany that specialize in the care of patients with immune-mediated neuropathies. We assessed the diagnosis, the approach to diagnostic work-up and follow-up, typical symptoms at manifestation and progression of the disease, and treatment data. RESULTS: This report includes data from 1529 patients per year treated for immune-mediated neuropathies, of whom 1320 suffered from chronic inflammatory demyelinating polyneuropathy (CIDP). Diagnostic work-up almost always included nerve conduction studies, electromyography, and lumbar puncture in accordance with current guidelines. The use of ultrasound, biopsy, and MRI varied. The most important clinical parameter for therapy monitoring in all centers was motor function in the clinical follow-up examinations. A wide range of different immunosuppressants was used for maintenance therapy in about 15% of patients. CONCLUSIONS: These data provide important epidemiological insights into the care of patients with immune-mediated neuropathies in Germany. The further development of specific recommendations for treatment and follow-up examinations is necessary to ensure a uniform standard of patient care. This effort is greatly facilitated by a structured collaboration between expert centers such as Neuritis Netz.

Astroglial and oligodendroglial markers in the cuprizone animal model for de- and remyelination.

Myelin loss with consecutive axon degeneration and impaired remyelination are the underlying causes of progressive disease in patients with multiple sclerosis. Astrocytes are suggested to play a major role in these processes. The unmasking of distinct astrocyte identities in health and disease would help to understand the pathophysiological mechanisms in which astrocytes are involved. However, the number of specific astrocyte markers is limited. Therefore, we performed immunohistochemical studies and analyzed various markers including GFAP, vimentin, S100B, ALDH1L1, and LCN2 during de- and remyelination using the toxic murine cuprizone animal model. Applying this animal model, we were able to confirm overlapping expression of vimentin and GFAP and highlighted the potential of ALDH1L1 as a pan-astrocytic marker, in agreement with previous data. Only a small population of GFAP-positive astrocytes in the corpus callosum highly up-regulated LCN2 at the peak of demyelination and S100B expression was found in a subset of oligodendroglia as well, thus S100B turned out to have a limited use as a particular astroglial marker. Additionally, numerous GFAP-positive astrocytes in the lateral corpus callosum did not express S100B, further strengthening findings of heterogeneity in the astrocytic population. In conclusion, our results acknowledged that GFAP, vimentin, LCN2, and ALDH1L1 serve as reliable marker to identify activated astrocytes during cuprizone-induced de- and remyelination. Moreover, there were clear regional and temporal differences in protein and mRNA expression levels and patterns of the studied markers, generally between gray and white matter structures.

Cuprizone-induced demyelination triggers a CD8-pronounced T cell recruitment.

The loss of myelinating oligodendrocytes is a key characteristic of many neurological diseases, including Multiple Sclerosis (MS). In progressive MS, where effective treatment options are limited, peripheral immune cells can be found at the site of demyelination and are suggested to play a functional role during disease progression. In this study, we hypothesize that metabolic oligodendrocyte injury, caused by feeding the copper chelator cuprizone, is a potent trigger for peripheral immune cell recruitment into the central nervous system (CNS). We used immunohistochemistry and flow cytometry to evaluate the composition, density, and activation status of infiltrating T lymphocytes in cuprizone-intoxicated mice and post-mortem progressive MS tissues. Our results demonstrate a predominance of CD8+ T cells along with high proliferation rates and cytotoxic granule expression, indicating an antigenic and pro-inflammatory milieu in the CNS of cuprizone-intoxicated mice. Numbers of recruited T cells and the composition of lymphocytic infiltrates in cuprizone-intoxicated mice were found to be comparable to those found in progressive MS lesions. Finally, amelioration of the cuprizone-induced pathology by treating mice with laquinimod significantly reduces the number of recruited T cells. Overall, this study provides strong evidence that toxic demyelination is a sufficient trigger for T cells to infiltrate the demyelinated CNS. Further investigation of the mode of action and functional consequence of T cell recruitment might offer promising new therapeutic approaches for progressive MS.

Autoantibody-associated psychiatric syndromes in children: link to adult psychiatry.

Studies show that psychiatric symptoms in adults and children are sometimes associated with serum neural autoantibodies. The significance of serum neural autoantibodies associated with psychiatric symptoms in children remains often unclear, but might be relevant for the extent and occurrence of psychiatric disease manifestation in later life, as well as therapy and outcome. For this narrative review, we sought articles listed in PubMed and published between 1988 and 2020 addressing the maternal-fetal transfer of neural autoantibodies and psychiatric disorders associated with serum neural autoantibodies. We identified six major subgroups of psychiatric disorders in children that are associated with serum neural autoantibodies: patients with attentional deficit hyperactivity disorder, autism spectrum disorder, obsessive compulsive disorder, Gilles de la Tourette syndrome, psychosis and catatonia. Furthermore, we summarized study findings from maternal-fetal transfer of Contactin-associated protein-like 2, N-methyl-D-aspartate receptor and fetal brain autoantibodies associated with behavioral effects in animals and humans. We hypothesize that the maternal transfer of serum neuronal autoantibodies during or after birth could result (1) in the ignition of an autoimmune-mediated inflammation having neurodevelopmental consequences for their children (autoimmune-priming-attack hypothesis) and (2) has a potential impact on the later manifestation of psychiatric disorders. Through this narrative review, we propose a diagnostic pathway for the clinical diagnosis of a potentially autoimmune origin of psychiatric symptoms in children while considering recent guidelines.

Immunophenotyping of cerebrospinal fluid cells by Chipcytometry.

BACKGROUND: The gold standard in cerebrospinal fluid (CSF) cell immunophenotyping is flow cytometry. Nevertheless, the small amount of CSF cells and the invasive character of lumbar puncture limit the spectrum of possible investigation. Chipcytometry, a modified approach to slide-based cytometry, might be a useful tool for CSF analysis due to the possibility of iterative staining, imaging, and bleaching cycles. The aim of this study was to compare flow cytometric leukocyte subset analysis with Chipcytometry comparing the percentage distribution of distinct cell populations and the T-cell CD4:CD8 ratio. Moreover, this study investigated the interpretability of chips loaded with CSF cells and examined the applicability of Chipcytometry in clinical practice. METHODS: 375 CSF samples from 364 patients were analyzed by Chipcytometry using an automated upright microscope. Cell surface molecules were stained using fluorescence-labeled monoclonal antibodies. For cross-validation experiments, flow cytometry data of six patients were analyzed and matched with Chipcytometry data. RESULTS: Our experiments showed a better agreement examined by Bland-Altman analysis for samples with CSF pleocytosis than for normocellular CSF samples. Data were more consistent for B cells and CD4:CD8 ratio than for T cells and monocytes. Advantages of Chipcytometry compared to flow cytometry are that cells once fixated can be analyzed for up to 20 months with additional markers at any time. The clinical application of Chipcytometry is demonstrated by two illustrative case reports. However, the low amount of CSF cells limits the analysis of normocellular CSF samples, as in our cohort only 11.7% of respectively loaded chips had sufficient cell density for further investigation compared to 59.8% of all chips loaded with samples with elevated cell counts (≥ 5/µl). Varying centrifuge settings, tube materials and resuspension technique were not able to increase the cell yield. CONCLUSION: In summary, the results demonstrate the great potential of Chipcytometry of CSF cells for both scientific questions and routine diagnostic. A new chip design optimized to meet the requirements of CSF would greatly enhance the value of this method. Cross-validation results need to be confirmed in a larger cohort.

The Persisting Significance of Oligoclonal Bands in the Dawning Era of Kappa Free Light Chains for the Diagnosis of Multiple Sclerosis.

The latest revision of the McDonald criteria of 2017 considers the evidence of an intrathecal immunoglobulin (IgG) synthesis as a diagnostic criterion for dissemination in time in multiple sclerosis. While the detection of oligoclonal bands is considered as the gold standard, determination of kappa free light chains might be a promising tool as a less technically demanding and cost saving method. However, data on the direct comparison between kappa free light chains and oligoclonal bands are limited and no study to date has used the highly sensitive method of polyacrylamide gels with consecutive silver staining for the demonstration of oligoclonal bands. Furthermore, the impact of the revised McDonald criteria of 2017 on the role of kappa free light chains as a biomarker has not been investigated. Nephelometry was used to determine kappa free light chains in cerebrospinal fluid (CSF) and serum from 149 patients with their first demyelinating event between 2010 and 2015. Clinical data, kappa free light chains, and oligoclonal band status were compared at the time of initial diagnosis and after follow-up to identify converters from clinically isolated syndrome to multiple sclerosis. An elevated kappa free light chain index (>5.9) was found in 79/83 patients (95%) with multiple sclerosis diagnosed at baseline, slightly less frequent than oligoclonal bands (98.8%). 18/25 (72%) patients who converted from clinically isolated syndrome to multiple sclerosis showed an elevated kappa free light chain index compared to 20/25 (80%) patients with positive oligoclonal bands. In patients with stable clinically isolated syndrome 7/41 (17%) displayed an elevated kappa free light chain index against 11/41 (27%) oligoclonal band positive patients. Only two patients with stable clinically isolated syndrome showed an elevated kappa free light chain index but were oligoclonal bands negative. In conclusion, determination of the kappa free light chain index is a promising diagnostic approach to assess intrathecal immunoglobulin synthesis in multiple sclerosis. Nevertheless, oligoclonal bands are highly prevalent in multiple sclerosis and can detect an intrathecal synthesis of IgG even when the kappa free light chain index is below the threshold. We consider sequential use of both methods as reasonable.

Mesenchymal stem cells do not exert direct beneficial effects on CNS remyelination in the absence of the peripheral immune system.

Remyelination is the natural repair mechanism in demyelinating disorders such as multiple sclerosis (MS) and it was proposed that it might protect from axonal loss. For unknown reasons, remyelination is often incomplete or fails in MS lesions and therapeutic treatments to enhance remyelination are not available. Recently, the transplantation of exogenous mesenchymal stem cells (MSC) has emerged as a promising tool to enhance repair processes. This included the animal model experimental autoimmune encephalomyelitis (EAE), a commonly used model for the autoimmune mechanisms of MS. However, in EAE it is not clear if the beneficial effect of MSC derives from a direct influence on brain resident cells or if this is an indirect phenomenon via modulation of the peripheral immune system. The aim of this study was to determine potential regenerative functions of MSC in the toxic cuprizone model of demyelination that allows studying direct effects on de- and remyelination without the influence of the peripheral immune system. MSC from three different species (human, murine, canine) were transplanted either intraventricularly into the cerebrospinal fluid or directly into the lesion of the corpus callosum at two time points: at the onset of oligodendrocyte progenitor cell (OPC) proliferation or the peak of OPC proliferation during cuprizone induced demyelination. Our results show that MSC did not exert any regenerative effects after cuprizone induced demyelination and oligodendrocyte loss. During remyelination, MSC did not influence the dynamics of OPC proliferation and myelin formation. In conclusion, MSC did not exert direct regenerative functions in a mouse model where peripheral immune cells and especially T lymphocytes do not play a role. We thus suggest that the peripheral immune system is required for MSC to exert their effects and this is independent from a direct influence of the central nervous system.

Diagnostic value of neurofilaments in differentiating motor neuron disease from multifocal motor neuropathy.

OBJECTIVE: To evaluate the performance of serum neurofilament light chain (NfL) and cerebrospinal fluid (CSF) phosphorylated neurofilament heavy chain (pNfH) as diagnostic biomarkers for the differentiation between motor neuron disease (MND) and multifocal motor neuropathy (MMN). METHODS: This retrospective, monocentric study included 16 patients with MMN and 34 incident patients with MND. A subgroup of lower motor neuron (MN) dominant MND patients (n = 24) was analyzed separately. Serum NfL was measured using Ella automated immunoassay, and CSF pNfH was measured using enzyme-linked immunosorbent assay. Area under the curve (AUC), optimal cutoff values (Youden's index), and correlations with demographic characteristics were calculated. RESULTS: Neurofilament concentrations were significantly higher in MND compared to MMN (p < 0.001), and serum NfL and CSF pNfH correlated strongly with each other (Spearman's rho 0.68, p < 0.001). Serum NfL (AUC 0.946, sensitivity and specificity 94%) and CSF pNfH (AUC 0.937, sensitivity 90.0%, specificity 100%) performed excellent in differentiating MND from MMN. Optimal cutoff values were ≥ 44.15 pg/mL (serum NfL) and ≥ 715.5 pg/mL (CSF pNfH), respectively. Similar results were found when restricting the MND cohort to lower MN dominant patients. Only one MMN patient had serum NfL above the cutoff. Two MND patients presented with neurofilament concentrations below the cutoffs, both featuring a slowly progressive disease. CONCLUSION: Neurofilaments are valuable supportive biomarkers for the differentiation between MND and MMN. Serum NfL and CSF pNfH perform similarly well and elevated neurofilaments in case of diagnostic uncertainty underpin MND diagnosis.

Automated analysis of gray matter damage in aged mice reveals impaired remyelination in the cuprizone model.

Multiple sclerosis is a chronic autoimmune disease of the central nervous system characterized by myelin loss, axonal damage, and glial scar formation. Still, the underlying processes remain unclear, as numerous pathways and factors have been found to be involved in the development and progression of the disease. Therefore, it is of great importance to find suitable animal models as well as reliable methods for their precise and reproducible analysis. Here, we describe the impact of demyelination on clinically relevant gray matter regions of the hippocampus and cerebral cortex, using the previously established cuprizone model for aged mice. We could show that bioinformatic image analysis methods are not only suitable for quantification of cell populations, but also for the assessment of de- and remyelination processes, as numerous objective parameters can be considered for reproducible measurements. After cuprizone-induced demyelination, subsequent remyelination proceeded slowly and remained incomplete in all gray matter areas studied. There were regional differences in the number of mature oligodendrocytes during remyelination suggesting region-specific differences in the factors accounting for remyelination failure, as, even in the presence of oligodendrocytes, remyelination in the cortex was found to be impaired. Upon cuprizone administration, synaptic density and dendritic volume in the gray matter of aged mice decreased. The intensity of synaptophysin staining gradually restored during the subsequent remyelination phase, however the expression of MAP2 did not fully recover. Microgliosis persisted in the gray matter of aged animals throughout the remyelination period, whereas extensive astrogliosis was of short duration as compared to white matter structures. In conclusion, we demonstrate that the application of the cuprizone model in aged mice mimics the impaired regeneration ability seen in human pathogenesis more accurately than commonly used protocols with young mice and therefore provides an urgently needed animal model for the investigation of remyelination failure and remyelination-enhancing therapies.

Clinical and paraclinical characteristics of optic neuritis in the context of the McDonald criteria 2017.

Optic neuritis is often an initial symptom in multiple sclerosis (MS) or clinically isolated syndrome (CIS), yet comprehensive studies using the 2017 McDonald criteria for MS are scarce. Patient records from our academic centre (2010-2018) were reviewed. Using the 2017 McDonald criteria, three groups were formed: MS optic neuritis (optic neuritis with confirmed MS), CIS optic neuritis (optic neuritis without confirmed MS) and suspected optic neuritis (sON). We compared clinical and paraclinical findings among the groups to identify predictors for CIS- or MS-optic neuritis. The study included 129 MS, 108 CIS, and 44 sON cases. The combination of visual impairment, dyschromatopsia, and retrobulbar pain was observed in 47% of MS patients, 42% of CIS patients, and 30% of sON patients. Dyschromatopsia was the strongest indicator of MS or CIS diagnosis in the backward regression model. 56% of MS patients had relative afferent pupillary defect, 61% optic nerve anomalies within magnetic resonance imaging, and 81% abnormal visual evoked potentials. Our results emphasize the challenges in diagnosing optic neuritis, as not all patients with objectively diagnosed MS exhibit the triad of typical symptoms. To address potentially missing clinical features, incorporating additional paraclinical findings is proposed.

Serum glial fibrillary acidic protein and disability progression in progressive multiple sclerosis.

OBJECTIVE: Progression prediction is a significant unmet need in people with progressive multiple sclerosis (pwPMS). Studies on glial fibrillary acidic protein (GFAP) have either been limited to single center with relapsing MS or were based solely on Expanded Disability Status Scale (EDSS), which limits its generalizability to state-of-the-art clinical settings and trials applying combined outcome parameters. METHODS: Serum GFAP and NfL (neurofilament light chain) were investigated in EmBioProMS participants with primary (PP) or secondary progressive MS. Six months confirmed disability progression (CDP) was defined using combined outcome parameters (EDSS, timed-25-foot walk test (T25FW), and nine-hole-peg-test (9HPT)). RESULTS: 243 subjects (135 PPMS, 108 SPMS, age 55.5, IQR [49.7-61.2], 135 female, median follow-up: 29.3 months [17.9-40.9]) were included. NfL (age-) and GFAP (age- and sex-) adjusted Z scores were higher in pwPMS compared to HC (p < 0.001 for both). 111 (32.8%) CDP events were diagnosed in participants with ≥3 visits (n = 169). GFAP Z score >3 was associated with higher risk for CDP in participants with low NfL Z score (i.e., ≤1.0) (HR: 2.38 [1.12-5.08], p = 0.025). In PPMS, GFAP Z score >3 was associated with higher risk for CDP (HR: 2.88 [1.21-6.84], p = 0.016). Risk was further increased in PPMS subjects with high GFAP when NfL is low (HR: 4.31 [1.53-12.13], p = 0.006). INTERPRETATION: Blood GFAP may help identify pwPPMS at risk of progression. Combination of high GFAP and low NfL levels could distinguish non-active pwPMS with particularly high progression risk.

Patient-reported outcome parameters and disability worsening in progressive multiple sclerosis.

OBJECTIVES: Detection and prediction of disability progression is a significant unmet need in people with progressive multiple sclerosis (PwPMS). Government and health agencies have deemed the use of patient-reported outcomes measurements (PROMs) in clinical practice and clinical trials a major strategic priority. Nevertheless, data documenting the clinical utility of PROMs in neurological diseases is scarce. This study evaluates if assessment of PROMs could track progression in PwPMS. METHODS: Emerging blood Biomarkers in Progressive Multiple Sclerosis (EmBioProMS) investigated PROMs (Beck depression inventory-II (BDI-II), multiple sclerosis impact scale-29 (MSIS-29), fatigue scale for motor and cognition (FSMC)) in PwPMS (primary [PPMS] and secondary progressive MS [SPMS]). PROMs were evaluated longitudinally and compared between participants with disability progression (at baseline; retrospective evidence of disability progression (EDP), and during follow up (FU); prospective evidence of confirmed disability progression (CDP)) and those without progression. In an independent cohort of placebo participants of the phase III ORATORIO trial in PPMS, the diagnostic and prognostic value of another PROMs score (36-Item Short Form Survey [SF-36]) regarding CDP was evaluated. RESULTS: EmBioProMS participants with EDP in the two years prior to inclusion (n = 136/227), or who suffered from CDP during FU (number of events= 88) had worse BDI-II, MSIS-29, and FSMC scores compared to PwPMS without progression. In addition, baseline MSIS29physical above 70th, 80th, and 90th percentiles predicted future CDP/ progression independent of relapse activity in EmBioProMS PPMS participants (HR of 3.7, 6.9, 6.7, p = 0.002, <0.001, and 0.001, respectively). In the placebo arm of ORATORIO (n = 137), the physical component score (PCS) of SF-36 worsened at week 120 compared to baseline, in cases who experienced progression over the preceding trial period (P = 0.018). Worse PCS at baseline was associated with higher hazard ratios of disability accumulation over the subsequent 120 weeks (HR: 2.01 [30th-], 2.11 [20th-], and 2.8 [10th percentile], P = 0.007, 0.012 and 0.005, respectively). CONCLUSIONS: PROMs could provide additional, practical, cost-efficient, and remotely accessible insight about disability progression in PMS through standardized, structured, and quantifiable patient feedback.

Clinical and paraclinical features of small fiber neuropathy in Sjögren's syndrome.

Sjögren's syndrome is a potentially treatable cause of Small Fiber Neuropathy (SFN)-a condition that severely affects patients' quality of life. We therefore aimed to characterize patients with SFN and Sjögren's syndrome to raise awareness of this disease and facilitate its early recognition as an essential step for appropriate treatment. In 97 SFN patients (median age 48 years, 77% female), we studied the clinical features associated with Sjögren's syndrome compared to the idiopathic SFN subtype. According to the current ACR/EULAR classification criteria (Shiboski et al., Ann Rheum Dis 76:9-16, 2017), 24/97 individuals (25%, median age 48.5 years, 75% female) were diagnosed with Sjögren's syndrome. We did not observe any differences in SFN-defining sensory plus symptoms. Furthermore, intraepidermal nerve fiber densities (IENFD) were significantly lower in patients with SFN and Sjögren's syndrome (mean 2.6 ± 1.2/mm) compared to patients with idiopathic SFN (mean 3.2 ± 1.5/mm; p = 0.048). There were no significant group differences when analyzing cerebrospinal fluid (CSF) parameters. We conclude that Sjögren's syndrome-associated SFN is difficult to distinguish from idiopathic forms based on initial clinical symptoms and CSF results. However, lower IENFD values in patients with Sjögren's syndrome-associated SFN might indicate a distinct different pathomechanism in this entity compared to idiopathic SFN.

The relevance of NMDA receptor antibody-specific index for diagnosis and prognosis in patients with anti-NMDA receptor encephalitis.

The clinical implications of the presence of anti-N-methyl-D-aspartate receptor (NMDAR)-specific intrathecal immunoglobulin G synthesis and whether it determines the diagnosis of anti-NMDAR encephalitis have not been thoroughly investigated yet. Thus, the aim of this study was to investigate whether the detection of intrathecal anti-NMDAR-specific IgG synthesis contributes to the diagnostic confirmation of anti-NMDAR encephalitis, to disease severity, and to prognosis in patients with positive serum anti-NMDAR-IgG. In this study, patients with detectable anti-NMDAR IgG in serum and/or cerebrospinal fluid (CSF) were included and separated into two groups that either met the 2016 criteria by Graus et al. of definite anti-NMDAR encephalitis (n = 27) or did not (n = 15). In a total, of 80 paired CSF/serum samples, antibody titers were titrated manually and end-point titer levels were carefully determined in a blinded manner to the subgroup attribution. The disease course was assessed via the modified Rankin Scale (mRS) and prognosis was estimated by the anti-NMDAR Encephalitis One-Year Functional Status (NEOS) score. With respect to whether the diagnostic Graus criteria for definite anti-NMDAR encephalitis were fulfilled, a significantly unequal distribution of intrathecal anti-NMDAR antibody-specific synthesis could be shown with a high negative predictive value in case of a negative anti-NMDAR antibody-specific index (NMDAR AI, p = .008. OR = 23.9, sensitivity = 1.0, specificity = 0.4, negative predictive value = 1). A weak correlation was found between the CSF antibody titer and mRS value at the time of sample collection (rs = .37, p = .008, 95% CI [.09, .59]). During the disease course a higher delta-mRS value formed of the mRS at initial presentation minus that at the last recorded presentation correlated with a higher NMDAR AI at first lumbar puncture (rs = - .56, p = .017, 95% CI [- .83, - .11]). No association with the prognostic NEOS score was found. In conclusion, a negative antibody-specific index for anti-NMDAR IgG antibodies has a highly negative predictive value for the diagnosis of anti-NMDAR encephalitis. Yet, a positive NMDAR AI alone does not allow the diagnosis of anti-NMDAR encephalitis.

Cranial nerve involvement in patients with immune-mediated neuropathy: An observational blink reflex study.

OBJECTIVE: This study aimed to assess cranial nerve involvement in a large adult cohort of patients with immune-mediated neuropathy undergoing immunoglobulin treatment by measuring blink reflex R1 latency prolongation in correlation with clinical findings and nerve conduction studies. METHODS: 104 patients underwent blink reflex examination and ulnar nerve conduction studies and were assessed by the Inflammatory Neuropathy Cause and Treatment disability score, the revised Amyotrophic lateral sclerosis functional rating scale (ALSFRS-R) and focused clinical examination. RESULTS: Prolonged R1 latencies were identified in 23 of 104 patients (22.1 %). These patients had more severe functional impairments according to the ALSFRS-R, yet only five clinically presented with bulbar dysfunction, facial- or trigeminal nerve impairment. Overall R1 latency was inversely correlated to ulnar motor conduction velocity. In preliminary follow-up assessments under continuous immunoglobulin treatment, prolonged R1 latencies partially improved. CONCLUSIONS: Cranial nerve involvement is a common feature in immune-mediated neuropathies and is associated with a more severe disease stage. Here, R1 prolongation was detected less frequently compared to previously reported untreated cohorts. SIGNIFICANCE: Blink reflex studies can detect subclinical cranial nerve involvement in immune-mediated neuropathies. Further studies are needed to evaluate the clinical utility of measuring R1 latency.

Comparative analysis of albumin quotient and total CSF protein in immune-mediated neuropathies: a multicenter study on diagnostic implications.

Introduction: Blood-cerebrospinal fluid (CSF) barrier dysfunction is pivotal for diagnosing immune-mediated neuropathies, especially in spinal nerve root inflammation. Typically, either total CSF protein or the CSF to serum albumin ratio (QAlb) is measured. Total CSF protein measurements have limitations, notably its fixed reference value regardless of age, in contrast to the age-dependent reference for QAlb. Our goal was to evaluate both markers in patients with immune-mediated neuropathies. Methods: In our multicenter research, we collected retrospective CSF data from patients suffering from immune-mediated neuropathies across four German research centers. These parameters were analyzed in relation to their clinical characteristics. Results: Out of 419 samples, 36 (8.6%) displayed a notable variation between total CSF protein and QAlb values. A detailed analysis revealed that patients displaying elevated QAlb but normal total CSF protein levels were significantly younger at disease onset (p = 0.01), at the time of diagnosis (p = 0.005), and when undergoing lumbar puncture (p = 0.001) compared to patients with elevated CSF protein and normal QAlb levels. These effects were especially evident for the subgroup of samples derived by female patients. Discussion: Our work confirms the crucial role of QAlb in diagnosing immune-mediated neuropathies and particularly its efficacy as a marker for evaluating the blood-CSF barrier in patients with an earlier disease onset. Considering the significance of the albumin quotient, its assessment is especially advisable in younger patients of female sex to avoid missing a potential barrier dysfunction that might be falsely negative when using total protein.

Effects of the COVID-19 Pandemic on Patients With NMO Spectrum Disorders and MOG-Antibody-Associated Diseases: COPANMO(G)-Study.

BACKGROUND AND OBJECTIVES: To evaluate the effects of the coronavirus disease 2019 (COVID-19) pandemic on the life of patients with neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated diseases (MOGAD). METHODS: This multicenter, cross-sectional study included data of 187 patients recruited from 19 different German and Austrian Neuromyelitis Optica Study Group (NEMOS) centers between July 2021 and March 2022. The effects of the pandemic on immunotherapeutic treatment and access to care, the possible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and the potential effect of vaccination against SARS-CoV-2 on disease incidence and relapse risk were assessed using a patient questionnaire. Health-related quality of life (HRQoL) was measured with the EuroQoL Group 5-Dimension 5-Level Scale (EQ-5D-5L). Demographic and clinical characteristics were retrieved from the NEMOS database. RESULTS: One hundred eighty-seven patients (75% women; median age 47 [range 21-86] years; median disease duration 5.5 [range 0-67] years; median Expanded Disability Status Scale 2.0 [range 0-8.0]; 51% aquaporin-4 immunoglobulin G (AQP4-IgG)-positive, 36% myelin oligodendrocyte glycoprotein (MOG)-IgG-positive 13% double-seronegative) were analyzed. Most patients maintained excellent access to healthcare services throughout the pandemic. Immunotherapy was not changed in 88% of patients. Ninety-one percent of all patients were satisfied with medical care during the pandemic. Nearly two-thirds (64%) of patients rated their risk of infection with SARS-CoV-2 as low or moderate. Among this study sample, 23 patients (12%) knowingly acquired an infection with SARS-CoV-2 and predominantly had a nonsevere course of illness (n = 22/23, 96%). The SARS-CoV-2 vaccination rate was 89%, with 4 cases of confirmed attack or first manifestation of NMOSD/MOGAD occurring in temporal association with the vaccination (range 2-9 days). The reported HRQoL did not decline compared with a prepandemic assessment (mean EQ-5D-5L index value 0.76, 95% bootstrap confidence interval [CI] 0.72-0.80; mean EQ-VAS 66.5, 95% bootstrap CI 63.5-69.3). DISCUSSION: This study demonstrates that, overall, patients with NMOSD/MOGAD affiliated with specialized centers received ongoing medical care during the pandemic. Patients' satisfaction with medical care and HRQoL did not decrease.