Optical coherence tomography-based assessment of retinal vascular pathology in cerebral small vessel disease

Background

Cerebral small vessel disease (CSVD) is a disorder of brain vasculature that causes various structural changes in the brain parenchyma, and is associated with various clinical symptoms such as cognitive impairment and gait disorders. Structural changes of brain arterioles cannot be visualized with routine imaging techniques in vivo. However, optical coherence tomography (OCT) is thought to be a “window to the brain”. Thus, retinal vessel parameters may correlate with CSVD characteristic brain lesions and cerebrospinal fluid biomarkers (CSF) of the neuropathological processes in CSVD like endothelial damage, microglial activation and neuroaxonal damage.

Methods

We applied OCT-based assessment of retinal vessels, magnetic resonance imaging (MRI), and CSF biomarker analysis in a monocentric prospective cohort of 24 patients with sporadic CSVD related stroke and cognitive impairment. MRI lesions were defined according to the STandards for ReportIng Vascular changes on nEuroimaging (STRIVE). Biomarkers were assessed using commercially available ELISA kits. Owing to the unavailability of an age-matched control-group lacking MRI-characteristics of CSVD, we compared the retinal vessel parameters in CSVD patients (73.8 ± 8.5 years) with a younger group of healthy controls (51.0 ± 16.0 years) by using an age- and sex-adjusted multiple linear regression analysis model.

Results

Among the parameters measured with OCT, the Wall to Lumen Ratio (WLR) but not Mean Wall Thickness (MWT) of the superior branch of the retinal artery correlated significantly with the volume of white matter hyperintensities on MRI (r_s = − 0.5) and with CSF-levels of Chitinase 3 like 1 protein (r_s = − 0.6), zona occludens 1 protein (r_s = − 0.5) and GFAP (r_s = − 0.4). MWT and WLR were higher in CSVD than in controls (28.9 μm vs. 23.9 μm, p = 0.001 and 0.32 vs. 0.25, p = 0.001).

Conclusions

In this exploratory study, WLR correlated with the volume of white matter hyperintensities, and markers of vascular integrity, microglial activation, and neuroaxonal damage in CSVD. Further prospective studies should clarify whether retinal vessel parameters and CSF biomarkers may serve to monitor the natural course and treatment effects in clinical studies on CSVD.

MOG-IgG in primary and secondary chronic progressive multiple sclerosis: a multicenter study of 200 patients and review of the literature

Background

Antibodies to human full-length myelin oligodendrocyte glycoprotein (MOG-IgG) as detected by new-generation cell-based assays have recently been described in patients presenting with acute demyelinating disease of the central nervous system, including patients previously diagnosed with multiple sclerosis (MS). However, only limited data are available on the relevance of MOG-IgG testing in patients with chronic progressive demyelinating disease. It is unclear if patients with primary progressive MS (PPMS) or secondary progressive MS (SPMS) should routinely be tested for MOG-IgG.

Objective

To evaluate the frequency of MOG-IgG among patients classified as having PPMS or SPMS based on current diagnostic criteria.

Methods

For this purpose, we retrospectively tested serum samples of 200 patients with PPMS or SPMS for MOG-IgG using cell-based assays. In addition, we performed a review of the entire English language literature on MOG-IgG published between 2011 and 2017.

Results

None of 139 PPMS and 61 SPMS patients tested was positive for MOG-IgG. Based on a review of the literature, we identified 35 further MOG-IgG tests in patients with PPMS and 55 in patients with SPMS; the only reportedly positive sample was positive just at threshold level and was tested in a non-IgG-specific assay. In total, a single borderline positive result was observed among 290 tests.

Conclusion

Our data suggest that MOG-IgG is absent or extremely rare among patients with PPMS or SPMS. Routine screening of patients with typical PPMS/SPMS for MOG-IgG seems not to be justified.

[Monitoring of blood parameters under course-modified MS therapy : Substance-specific relevance and current recommendations for action]

With the approval of various substances for the immunotherapy of multiple sclerosis (MS), treatment possibilities have improved significantly over the last few years. Indeed, the choice of individually tailored preparations and treatment monitoring for the treating doctor is becoming increasingly more complex. This is particularly applicable for monitoring for a treatment-induced compromise of the immune system. The following article by members of the German Multiple Sclerosis Skills Network (KKNMS) and the task force "Provision Structures and Therapeutics" summarizes the practical recommendations for approved immunotherapy for mild to moderate and for (highly) active courses of MS. The focus is on elucidating the substance-specific relevance of particular laboratory parameters with regard to the mechanism of action and the side effects profile. To enable appropriate action to be taken in clinical practice, any blood work changes that can be expected, in addition to any undesirable laboratory findings and their causes and relevance, should be elucidated.

[Strategies for cerebrospinal fluid analysis - Integrated results report]

Cerebrospinal fluid (CSF) analysis requires a combined assessment of all individual test findings in an integrated total report in order to achieve a reliable and specific diagnostic conclusion. Such a standard assessment strategy allows the identification of disease-typical result patterns and plausibility checks to avoid analytical errors. The integrated total report consists of 1) a basic CSF program with cytological and protein chemical parameters, 2) an expanded CSF program with special parameters for detection of pathogens and markers of neurodegeneration and 3) a final contextual interpretation considering methodological and clinical aspects.

Axonal damage markers in the cerebrospinal fluid of patients with clinically isolated syndrome improve predicting conversion to definite multiple sclerosis

Clinically isolated syndrome (CIS) represents the earliest phase of multiple sclerosis (MS). This study tested whether biomarkers for axonal degeneration can improve upon sensitivity and specificity of magnetic resonance imaging (MRI) parameters in predicting conversion from CIS to MS. Patients with CIS ( n=52), relapsing-remitting MS (RRMS, n=38) and age-matched controls ( n=25) were included. Cerebrospinal fluid (CSF) levels of tau and neurofilaments (NfHSMI35) were measured using ELISA. The MRI T2-lesion load and the Expanded Disability Status Scale (EDSS) were recorded. CSF tau and NfHSMI35 were elevated in CIS compared to controls (p<0.05). RRMS patients with acute relapse had higher NfHSMI35 levels than stable patients. Tau and NfHSMI35 levels correlated with EDSS in CIS and RRMS. In RRMS, the number of T2-lesions correlated with tau levels ( R=0.53, P=0.01). The sensitivity predicting the conversion from CIS to MS was higher for the combination of CSF markers (either tau or NfHSMI35 elevated) than for MRI (40 versus 34%), but could be further increased to 60% if CSF and MRI criteria were combined. Similarly, the combination of tau and NfHSMI35 showed higher specificity (94%) than MRI (82%). Tau and NfHSMI35 are valuable biomarkers for axonal damage in the CIS patients. Predicting conversion from CIS to MS can be improved if CSF markers are combined with MRI.

Tau protein level in cerebrospinal fluid is increased in patients with early multiple sclerosis

Axonal damage has been proposed as the major substrate of permanent clinical disability in multiple sclerosis. Tau protein, a microtubule-associated protein localised in neuronal axons, may serve as a biochemical surrogate marker to evaluate axonal damage in vivo.We intended to determine the extent of axonal damage in different stages and clinical subtypes of MS by investigating cerebrospinal fluid tau concentrations. Tau was measured using an immunoassay in 35 patients with relapsing—remitting MS, eight patients with secondary progressive MS, nine patients with primary progressive MS, 50 patients with clinically isolated syndrome suggestive of early MS and 46 normal controls. Cerebrospinal fluid tau was significantly elevated in MS compared with normal controls (median 206.0 pg/mL versus152.0 pg/mL;P=0.002). No significant difference among different subtypes of MS could be detected, although highest levels were found in very early disease stages. There was a significant elevation of CSF tau among patients with gadolinium-enhancing brain lesions in magnetic resonance imaging (P=0.02) and a tendency towards higher CSF tau levels in patients with pronounced intrathecal IgG synthesis, supporting the notion that axonal damage is influenced by inflammatory activity.

The chemokine CXCL13 is elevated in the cerebrospinal fluid of patients with neurosyphilis

Background

The chemokine CXCL13 has been discussed as a diagnostic parameter with high specificity for Lyme neuroborreliosis (LNB) and as a marker of disease activity. Neurosyphilis and LNB share similar characteristics. We investigated retrospectively CXCL13 levels in the cerebrospinal fluid (CSF) of patients with neurosyphilis at initial diagnosis and during treatment.

Results

Five patients with neurosyphilis were identified retrospectively using an electronic database in a tertiary care hospital from 2005 to 2012. CXCL13 levels were measured using an ELISA. Five patients with definite LNB and 10 patients with multiple sclerosis (MS) served as controls. Median CXCL13 levels at baseline were 972 pg/mL for neurosyphilis patients, 8,000 pg/mL for LNB patients, and 7.8 pg/mL for MS patients. Patients with LNB and neurosyphilis showed significantly higher CXCL13 levels in their CSF compared to MS patients (p < 0.05, p < 0.001, respectively). CXCL13 levels in the CSF declined during treatment.

Conclusion

CXCL13 levels in the CSF of patients with neurosyphilis can be as high as in patients with LNB, exceeding the proposed threshold of 250 pg/mL for the diagnosis of LNB. Patients with encephalitic/myelitic syndromes appear to have especially high levels of CXCL13. Clinicians should be aware that high levels of CXCL13 are not found exclusively in LNB but also in other infectious diseases of the CNS.

Conversion from clinically isolated syndrome to multiple sclerosis: A large multicentre study

Background and objective:

We explored which clinical and biochemical variables predict conversion from clinically isolated syndrome (CIS) to clinically definite multiple sclerosis (CDMS) in a large international cohort.

Methods:

Thirty-three centres provided serum samples from 1047 CIS cases with at least two years’ follow-up. Age, sex, clinical presentation, T2-hyperintense lesions, cerebrospinal fluid (CSF) oligoclonal bands (OCBs), CSF IgG index, CSF cell count, serum 25-hydroxyvitamin D3 (25-OH-D), cotinine and IgG titres against Epstein-Barr nuclear antigen 1 (EBNA-1) and cytomegalovirus were tested for association with risk of CDMS.

Results:

At median follow-up of 4.31 years, 623 CIS cases converted to CDMS. Predictors of conversion in multivariable analyses were OCB (HR = 2.18, 95% CI = 1.71–2.77, p < 0.001), number of T2 lesions (two to nine lesions vs 0/1 lesions: HR = 1.97, 95% CI = 1.52–2.55, p < 0.001; >9 lesions vs 0/1 lesions: HR = 2.74, 95% CI = 2.04–3.68, p < 0.001) and age at CIS (HR per year inversely increase = 0.98, 95% CI = 0.98–0.99, p < 0.001). Lower 25-OH-D levels were associated with CDMS in univariable analysis, but this was attenuated in the multivariable model. OCB positivity was associated with higher EBNA-1 IgG titres.

Conclusions:

We validated MRI lesion load, OCB and age at CIS as the strongest independent predictors of conversion to CDMS in this multicentre setting. A role for vitamin D is suggested but requires further investigation.

Optical coherence tomography does not support optic nerve involvement in amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

In recent years a possible non-motor involvement of the nervous system in amyotrophic lateral sclerosis (ALS) has come into the focus of research and has been investigated by numerous techniques. Optical coherence tomography (OCT) - with its potential to reveal neuroaxonal retinal damage - may be an appropriate tool to investigate whether the anterior visual pathway is involved. Our aim was to determine whether OCT-based measures of retinal nerve fiber layer, ganglion cell layer, inner nuclear layer and outer nuclear layer thickness are abnormal in ALS, or correlated with disease severity.

METHODS

Seventy-six ALS patients (144 eyes) and 54 healthy controls (108 eyes; HCs) were examined with OCT, including automated intraretinal macular segmentation. ALS disease severity was determined with the Amyotrophic Lateral Sclerosis Functional Rating Scale - Revised.

RESULTS

There was no significant difference between ALS patients and HCs in any of the examined OCT measures. Moreover, OCT parameters showed no correlation with clinical measures of disease severity.

CONCLUSIONS

These findings indicate that involvement of the anterior visual pathway is not one of the non-motor manifestations of ALS.

[Current cerebrospinal fluid diagnostics for pathogen-related diseases]

Cerebrospinal fluid (CSF) analysis is of utmost importance to establish an early diagnosis of central nervous system (CNS) infections and to start appropriate therapy. The CSF white cell count, lactate concentration and total protein levels are usually available very quickly even from non-specialized laboratories and the combination of these parameters often provides sufficient information for decision-making in emergency cases. It is, however, not always possible to identify the underlying infective agent despite further CSF analyses, such as bacterial and fungal staining, evaluation of the blood-CSF barrier function, intrathecal immunoglobulin synthesis and oligoclonal IgG bands. Therefore, close communication between the laboratory and the clinician is an important prerequisite to specify additional pathogen-related diagnostic measures for successful confirmation of the diagnosis.

Cerebrospinal fluid parameters of B cell-related activity in patients with active disease during natalizumab therapy

Recently, the disappearance of oligoclonal bands (OCBs) from the cerebrospinal fluid (CSF) of a few natalizumab-treated patients with multiple sclerosis (MS) has been reported. This is interesting since CSF-restricted OCB are believed to persist in MS. We pooled CSF data from 14 MS centers to obtain an adequate sample size for investigating the suspected changes in central nervous system (CNS)-restricted humoral immune activities in the context of natalizumab therapy. In a retrospective chart analysis, CSF parameters of blood-CSF barrier integrity and intrathecal IgG production from 73 natalizumab-treated MS patients requiring a diagnostic puncture for exclusion of progressive multifocal leukoencephalopathy were compared with CSF data obtained earlier in the course of disease before natalizumab therapy. At the time of repeat lumbar puncture, local IgG production (according to Reibergram) was significantly reduced (p < 0.0001) and OCB had disappeared in 16% of the patients. We therefore conclude that natalizumab therapy interferes with intrathecal antibody production at least in a significant number of patients.

CSF glial markers correlate with survival in amyotrophic lateral sclerosis

BACKGROUND

In neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), CSF biomarkers are increasingly studied to evaluate their relevance for differential diagnosis, disease progression, and understanding of pathophysiologic processes.

OBJECTIVE

To identify a biomarker profile of neuronal and glial CSF proteins to discriminate ALS from other motor neuron diseases (MND) and to assess whether baseline levels of CSF measures in ALS are associated with the course of the disease.

METHODS

A total of 122 consecutive subjects with MND were included in this cross-sectional study (ALS, n = 75; lower motor neuron syndrome, n = 39; upper motor neuron diseases, n = 8). Clinical follow-up included 76 patients. We determined baseline levels of protein tau and astroglial S100beta in CSF and microglial sCD14 in CSF and serum in relation to diagnosis, duration of disease, and survival.

RESULTS

CSF tau was significantly elevated in ALS and upper motor neuron diseases as compared to lower motor neuron diseases and controls. CSF S100beta levels were significantly lower in lower motor neuron diseases as compared to other MND. CSF concentrations of S100beta and sCD14 correlated with the survival time in patients with ALS.

CONCLUSIONS

In motor neuron diseases, CSF tau elevation indicates the degeneration of upper motor neurons, while S100 beta and sCD14 may indicate the activation of CNS glial cells. Because S100beta and sCD14 concentrations correlate with survival in amyotrophic lateral sclerosis (ALS), we suppose that the combination of both markers may be useful to obtain prognostic information in patients with ALS.

A consensus protocol for the standardization of cerebrospinal fluid collection and biobanking

There is a long history of research into body fluid biomarkers in neurodegenerative and neuroinflammatory diseases. However, only a few biomarkers in CSF are being used in clinical practice. One of the most critical factors in CSF biomarker research is the inadequate powering of studies because of the lack of sufficient samples that can be obtained in single-center studies. Therefore, collaboration between investigators is needed to establish large biobanks of well-defined samples. Standardized protocols for biobanking are a prerequisite to ensure that the statistical power gained by increasing the numbers of CSF samples is not compromised by preanalytical factors. Here, a consensus report on recommendations for CSF collection and biobanking is presented, formed by the BioMS-eu network for CSF biomarker research in multiple sclerosis. We focus on CSF collection procedures, preanalytical factors, and high-quality clinical and paraclinical information. The biobanking protocols are applicable for CSF biobanks for research targeting any neurologic disease.

A novel presenilin1 mutation (Q223R) associated with early onset Alzheimer's disease, dysarthria and spastic paraparesis and decreased Abeta levels in CSF

BACKGROUND AND PURPOSE

A novel presenilin1 (PSEN1) mutation associated with dementia and spastic paraplegia in a family with five affected individuals is described. The index patient was a 35-year-old man presenting with cognitive decline, behavioural symptoms, dysarthria, and gait disorder due to spasticity.

METHODS AND RESULTS

Genetic analysis revealed a missense mutation Gln223Arg in exon 7. Initial CSF analysis revealed drastically decreased Abeta42 level despite marginally decreased FDG metabolism.

CONCLUSION

Cerebrospinal fluid biomarker analysis might point towards genetic analysis of PSEN1 in patients with positive family history and age of onset below 60 years.

Applying new research criteria for diagnosis of early Alzheimer's disease: sex and intelligence matter

Alzheimer's disease (AD) can be diagnosed according to new research criteria proposed recently (Dubois et al., 2007). Diagnosis is made on grounds of episodic memory deficits and one pathological biomarker: cerebrospinal fluid (CSF) or structural/functional imaging. Goal was to investigate the dependence of episodic memory function on material (verbal, visuospatial), gender and premorbid intellectual ability (IQ). The new research criteria of AD were applied retrospectively using data of 68 patients (Mini-Mental-Status Examination, MMSE ≥ 22) from a university memory clinic. Women with lower IQ performed worse on visuospatial episodic memory than women with higher IQ and men with the same IQ. Thus, women with lower IQ appear to be particularly vulnerable to visuospatial episodic memory deficits despite similar CSF tau values indicating a similar activity of the neurodegenerative process. Gender, premorbid IQ, and visuospatial material need to be considered in the assessment of episodic memory breakdown applying the newly proposed research criteria for the diagnosis of AD.

Tauopathies with parkinsonism: clinical spectrum, neuropathologic basis, biological markers, and treatment options

Tauopathies with parkinsonism represent a spectrum of disease entities unified by the pathologic accumulation of hyperphosphorylated tau protein fragments within the central nervous system. These pathologic characteristics suggest shared pathogenetic pathways and possible molecular targets for disease-modifying therapeutic interventions. Natural history studies, for instance, in progressive supranuclear palsy, frontotemporal dementia with parkinsonism linked to chromosome 17, corticobasal degeneration, and Niemann-Pick disease type C as well as in amyotrophic lateral sclerosis/Parkinson-dementia complex permit clinical characterization of the disease phenotypes and are crucial to the development and validation of biological markers for differential diagnostics and disease monitoring, for example, by use of neuroimaging or proteomic approaches. The wide pathologic and clinical spectrum of the tauopathies with parkinsonism is reviewed in this article, and perspectives on future advances in the understanding of the pathogenesis are given, together with potential therapeutic strategies.

Tauopathies with parkinsonism: clinical spectrum, neuropathologic basis, biological markers, and treatment options

Tauopathies with parkinsonism represent a spectrum of disease entities unified by the pathologic accumulation of hyperphosphorylated tau protein fragments within the central nervous system. These pathologic characteristics suggest shared pathogenetic pathways and possible molecular targets for disease-modifying therapeutic interventions. Natural history studies, for instance, in progressive supranuclear palsy, frontotemporal dementia with parkinsonism linked to chromosome 17, corticobasal degeneration, and Niemann-Pick disease type C as well as in amyotrophic lateral sclerosis/Parkinson-dementia complex permit clinical characterization of the disease phenotypes and are crucial to the development and validation of biological markers for differential diagnostics and disease monitoring, for example, by use of neuroimaging or proteomic approaches. The wide pathologic and clinical spectrum of the tauopathies with parkinsonism is reviewed in this article, and perspectives on future advances in the understanding of the pathogenesis are given, together with potential therapeutic strategies.

Polyspecific, antiviral immune response distinguishes multiple sclerosis and neuromyelitis optica

BACKGROUND

A polyspecific, intrathecal humoral immune response against neurotropic viruses such as measles, rubella and varicella zoster virus (MRZ reaction, MRZR) is present in 80-100% of patients with multiple sclerosis (MS), but has not to date been evaluated in patients with neuromyelitis optica (NMO).

AIMS

To evaluate whether MRZR distinguishes NMO and MS.

METHODS

20 patients with NMO and 42 with MS were included. The intrathecal synthesis of antibodies against measles, rubella and varicella zoster virus was detected by calculation of the respective antibody indices (AI).

RESULTS

A positive MRZ reaction, as defined by a combination of at least two positive AIs, was found in 37/42 MS, but in only 1/20 NMO patients (p<0.0001). Median AI values differed significantly between the groups (p<0.0005).

CONCLUSIONS

The polyspecific antiviral humoral immune response characteristic for MS is widely missing in NMO, irrespective of the NMO-IgG status of the patients. Our findings further strengthen the case for NMO being pathologically distinct from MS.