Prospective phase II clinical trial of autologous haematopoietic stem cell transplant for treatment refractory multiple sclerosis

BACKGROUND

Autologous haematopoietic stem cell transplantation (AHSCT) has been explored as a therapeutic intervention in multiple sclerosis (MS) over the last two decades; however, prospective clinical trials of the most common myeloablative conditioning regimen, BEAM, are limited. Furthermore, patient selection, optimal chemotherapeutic regimen and immunological changes associated with disease response require ongoing exploration. We present the outcomes, safety and immune reconstitution (IR) of patients with active, treatment refractory MS.

METHODS

This study was a single-centre, phase II clinical trial of AHSCT for patients with active relapsing remitting (RRMS) and secondary progressive MS (SPMS). Patients underwent AHSCT using BEAM (carmustine, etoposide, cytarabine, melphalan)+antithymocyte globulin chemotherapeutic regimen.

OUTCOMES

The primary outcome was event-free survival (EFS); defined as no clinical or radiological relapses and no disability progression. Multiparameter flow cytometry was performed for evaluation of post-transplant IR in both MS and lymphoma patients receiving the same chemotherapy regimen.

RESULTS

Thirty-five patients (20 RRMS, 15 SPMS) completed AHSCT, with a median follow-up of 36 months (range 12-66). The median Expanded Disability Status Scores (EDSS) was 6 (2-7) and patients had failed a median of 4 (2-7) disease modifying therapies. 66% failed treatment with natalizumab. EFS at 3 years was 60%, (70% RRMS). Sustained improvement in EDSS was seen in 15 (44%) of patients. There was no treatment-related mortality. A sustained rise in CD39⁺ T regulatory cells, immunosuppressive CD56^hi natural killer cells and ablation of proinflammatory mucosal-associated invariant T cells was seen for 12 months following AHSCT in patients with MS. These changes did not occur in patients with lymphoma receiving the same chemotherapy for AHSCT.

CONCLUSIONS

The EFS in our MS cohort is significantly greater than other high-efficacy immunosuppressive therapies and similar to other AHSCT studies despite a more heavily pretreated cohort.

TRIAL REGISTRATION NUMBER

ACTRN12613000339752.

Conduction block in immune-mediated neuropathy: paranodopathy versus axonopathy

BACKGROUND AND PURPOSE

Conduction block is a pathognomonic feature of immune-mediated neuropathies. The aim of this study was to advance understanding of pathophysiology and conduction block in chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN).

METHODS

A multimodal approach was used, incorporating clinical phenotyping, neurophysiology, immunohistochemistry and structural assessments.

RESULTS

Of 49 CIDP and 14 MMN patients, 25% and 79% had median nerve forearm block, respectively. Clinical scores were similar in CIDP patients with and without block. CIDP patients with median nerve block demonstrated markedly elevated thresholds and greater threshold changes in threshold electrotonus, whilst those without did not differ from healthy controls in electrotonus parameters. In contrast, MMN patients exhibited marked increases in superexcitability. Nerve size was similar in both CIDP groups at the site of axonal excitability. However, CIDP patients with block demonstrated more frequent paranodal serum binding to teased rat nerve fibres. In keeping with these findings, mathematical modelling of nerve excitability recordings in CIDP patients with block support the role of paranodal dysfunction and enhanced leakage of current between the node and internode. In contrast, changes in MMN probably resulted from a reduction in ion channel density along axons.

CONCLUSIONS

The underlying pathologies in CIDP and MMN are distinct. Conduction block in CIDP is associated with paranodal dysfunction which may be antibody-mediated in a subset of patients. In contrast, MMN is characterized by channel dysfunction downstream from the site of block.

Evidence of Müller Glial Dysfunction in Patients with Aquaporin-4 Immunoglobulin G-Positive Neuromyelitis Optica Spectrum Disorder

PURPOSE

To compare functional and structural changes in the retina in patients with aquaporin-4 immunoglobulin G (AQP4-IgG)-positive neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS).

DESIGN

Cross-sectional study; biochemical study of human retinas.

PARTICIPANTS

A total of 181 participants, including 22 consecutive patients (44 eyes) with NMOSD, 131 patients (262 eyes) with multiple sclerosis (MS), and 28 normal subjects (56 eyes). In addition, 8 eyeballs from healthy donors were used for biochemical analysis.

METHODS

Full-field electroretinography (ERG) and spectral-domain OCT were performed in all the subjects. Topography of AQP4 expression and Müller glial distribution were analyzed using Western blotting and immunohistochemistry.

MAIN OUTCOME MEASURES

Full-field ERG parameters, including amplitudes and peak times. Tissue volume of each of the retinal layers at the fovea by OCT segmentation. Levels of AQP4 expression at different retinal regions.

RESULTS

The b-wave amplitude was significantly reduced in patients with AQP4-IgG+ NMOSD in scotopic ERGs (compared with AQP4-IgG- subjects, patients with MS, and normal controls) but not in photopic ERGs. Further analysis showed that this b-wave change was mainly caused by reduction of the slow PII component, suggesting specific Müller cell dysfunction. We also found thinning of specific retinal layers at the fovea in patients with AQP4-IgG+ NMOSD, in the Henle fiber outer nuclear layer (HFONL) and the inner segment (IS) layer, but not in the inner nuclear layer (INL), outer plexiform layer (OPL), or outer segment (OS) layer. Furthermore, there was a significant association between foveal HFONL-IS complex thinning and scotopic b-wave amplitude reduction (P = 0.005∼0.01, fixed-effects model). Western blotting demonstrated that Müller cell-specific AQP4 was expressed at a higher level at the fovea than the peripheral retina. Immunohistochemical studies revealed that the specific foveal thinning reflected the topography of AQP4 expression and Müller glial distribution in the human macula.

CONCLUSIONS

This study provides in vivo structural and functional evidence of Müller glial dysfunction in eyes of patients with AQP4-IgG+ NMOSD. Topography of retinal structural change is supported by distribution of Müller cells and patterns of AQP4 expression. The study suggests that visual electrophysiology and retinal imaging could be useful biomarkers to assess the potential retinal astrocytopathy in NMOSD.

Comparing longitudinal brain atrophy measurement techniques in a real-world multiple sclerosis clinical practice cohort: towards clinical integration?

Background:

Whole brain atrophy (WBA) estimates in multiple sclerosis (MS) correlate more robustly with clinical disability than traditional, lesion-based metrics. We compare Structural Image Evaluation using Normalisation of Atrophy (SIENA) with the icobrain longitudinal pipeline (icobrain long), for assessment of longitudinal WBA in MS patients.

Methods:

Magnetic resonance imaging (MRI) scan pairs [1.05 (±0.15) year separation] from 102 MS patients were acquired on the same 3T scanner. Three-dimensional (3D) T1-weighted and two-dimensional (2D)/3D fluid-attenuated inversion-recovery sequences were analysed. Percentage brain volume change (PBVC) measurements were calculated using SIENA and icobrain long. Statistical correlation, agreement and consistency between methods was evaluated; MRI brain volumetric and clinical data were compared. The proportion of the cohort with annualized brain volume loss (aBVL) rates ⩾ 0.4%, ⩾0.8% and ⩾0.94% were calculated. No evidence of disease activity (NEDA) 3 and NEDA 4 were also determined.

Results:

Mean annualized PBVC was −0.59 (±0.65)% and −0.64 (±0.73)% as measured by icobrain long and SIENA. icobrain long and SIENA-measured annualized PBVC correlated strongly, r = 0.805 (p < 0.001), and the agreement [intraclass correlation coefficient (ICC) 0.800] and consistency (ICC 0.801) were excellent. Weak correlations were found between MRI metrics and Expanded Disability Status Scale scores. Over half the cohort had aBVL ⩾ 0.4%, approximately a third ⩾0.8%, and aBVL was ⩾0.94% in 28.43% and 23.53% using SIENA and icobrain long, respectively. NEDA 3 was achieved in 35.29%, and NEDA 4 in 15.69% and 16.67% of the cohort, using SIENA and icobrain long to derive PBVC, respectively.

Discussion:

icobrain long quantified longitudinal WBA with a strong level of statistical agreement and consistency compared to SIENA in this real-world MS population. Utility of WBA measures in individuals remains challenging, but show promise as biomarkers of neurodegeneration in MS clinical practice. Optimization of MRI analysis algorithms/techniques are needed to allow reliable use in individuals. Increased levels of automation will enable more rapid clinical translation.

Deep sequencing of circulating exosomal microRNA allows non-invasive glioblastoma diagnosis

Exosomes are nano-sized extracellular vesicles released by many cells that contain molecules characteristic of their cell of origin, including microRNA. Exosomes released by glioblastoma cross the blood–brain barrier into the peripheral circulation and carry molecular cargo distinct to that of “free-circulating” miRNA. In this pilot study, serum exosomal microRNAs were isolated from glioblastoma (n = 12) patients and analyzed using unbiased deep sequencing. Results were compared to sera from age- and gender-matched healthy controls and to grade II–III (n = 10) glioma patients. Significant differentially expressed microRNAs were identified, and the predictive power of individual and subsets of microRNAs were tested using univariate and multivariate analyses. Additional sera from glioblastoma patients (n = 4) and independent sets of healthy (n = 9) and non-glioma (n = 10) controls were used to further test the specificity and predictive power of this unique exosomal microRNA signature. Twenty-six microRNAs were differentially expressed in serum exosomes from glioblastoma patients relative to healthy controls. Random forest modeling and data partitioning selected seven miRNAs (miR-182-5p, miR-328-3p, miR-339-5p, miR-340-5p, miR-485-3p, miR-486-5p, and miR-543) as the most stable for classifying glioblastoma. Strikingly, within this model, six iterations of these miRNA classifiers could distinguish glioblastoma patients from controls with perfect accuracy. The seven miRNA panel was able to correctly classify all specimens in validation cohorts (n = 23). Also identified were 23 dysregulated miRNAs in IDH^MUT gliomas, a partially overlapping yet distinct signature of lower-grade glioma. Serum exosomal miRNA signatures can accurately diagnose glioblastoma preoperatively. miRNA signatures identified are distinct from previously reported “free-circulating” miRNA studies in GBM patients and appear to be superior.

A diagnostic test for short regulatory RNA molecules contained within tiny secreted vesicles in the bloodstream can accurately pick up signs of glioblastoma brain cancer. Researchers in Australia led by Michael Buckland and Kim Kaufman from the Royal Prince Alfred Hospital and the University of Sydney isolated circulating vesicles, called exosomes, from patients with glioblastoma or lower-grade brain cancers known as gliomas as well as healthy controls. Next-generation sequencing revealed a panel of 26 microRNAs contained within the exosomes that were differentially expressed in glioblastoma samples relative to healthy controls. (A different but partially overlapping set of 23 microRNAs also helped distinguish patients with a mutant subtype of glioma.) The researchers narrowed down the list to the seven microRNAs with the most predictive power. Testing for just these microRNAs reliably diagnosed glioblastoma with greater precision than previously reported panels of “free-circulating” microRNAs.

Pathophysiological basis of low contrast visual acuity loss in multiple sclerosis

Objective

There is currently an urgent need for reliable clinical biomarkers of remyelination to be used in Phase 2 and Phase 3 clinical trials. Low contrast visual acuity (LCVA) has been suggested as a functional measure of the integrity of the visual pathway. Therefore, the aim of this study was to elucidate the potential contribution of axonal loss and demyelination to LCVA loss in MS patients.

Method

In this study, 50 consecutive relapsing remitting MS patients with a previous history of unilateral optic neuritis were enrolled. Using the linear regression model, we assessed the relative contribution of multifocal Visual Evoked Potentials (mfVEP) latency and Retinal Nerve Fiber Layer (RNFL) thickness to LCVA deficit.

Results

Intereye asymmetry of mfVEP latency and RNFL thickness correlated significantly with intereye asymmetry of LCVA (P < 0.001). A linear regression model demonstrated increased predictive power of LCVA when mfVEP latency and RNFL thinning were combined (reaching R ² = 0.67) and confirmed a higher predictive value of RNFL thinning compared to mfVEP latency delay for both contrast levels. However, elimination of subjects with severe axonal loss dramatically increased the relative contribution of mfVEP latency, with contribution of RNFL thickness losing significance for both 1.25% and 2.5% LCVA.

Interpretation

While retinal ganglion cell axonal loss is a superior predictor of LCVA, the degree of demyelination contributes significantly to worsening of LCVA, particularly when patients with severe axonal loss are excluded. These results support the feasibility of using LCVA as a functional biomarker in remyelination therapy trials, providing appropriate patient's selection criteria are implemented.

Successful implementation of an automated electronic support system for patient safety monitoring: The alemtuzumab in multiple sclerosis safety systems (AMS3) study

BACKGROUND

Alemtuzumab is a highly effective treatment for relapsing-remitting multiple sclerosis (MS) but requires ongoing pathology monitoring for autoimmune adverse effects. The Alemtuzumab in MS Safety Systems (AMS3) study evaluated the implementation of an automated pathology-monitoring system.

OBJECTIVES

To develop an efficient automated clinical decision support system (CDSS) to electronically prompt and track pathology collection and to provide prescribers and patients with customised alerts of abnormal results for identified risks.

METHODS

A total of 10 patients with relapsing-remitting MS treated with alemtuzumab were enrolled to test the system. Standard care laboratory monitoring was performed and compared to the performance of the CDSS.

RESULTS

The automated CDSS, an integrated patient smartphone application and an additional pre-screening tool were all successfully developed. Compliance with pathology monitoring was 96.7%. The automated analysis of pathology results was significantly faster than standard care neurologist review (p < 0.001). The system correctly identified and alerted abnormalities, including one case of immune thrombocytopenia (ITP) while the treating neurologist was on leave, enabling prompt treatment of serious adverse events. During the course of the study, the CDSS was deployed throughout Australia.

CONCLUSION

We successfully developed automated pathology monitoring with a CDSS, demonstrating real-world benefits of high compliance and timely alerting of important results.

103 Exploring the influence of quantitative magnetic resonance imaging on decision-making in multiple sclerosis clinical practice

Introduction

Quantitative magnetic resonance imaging (MRI) analysis is currently used in multiple sclerosis (MS) clinical trials. Quantitative MRI (QMRI) data derived using formal analysis techniques is not used in routine MS clinical practice and its effect on clinical decision-making is unknown. The study objective is to explore the influence that QMRI data has on clinical decision-making in real-world MS patients.

Methods

Clinical MS brain MRI scans (separated by one-year minimum, acquired on the same scanner from the same patient) were evaluated. All patients were on the same disease-modifying therapy (DMT) six months prior to and during the study. QMRI analyses were performed on scan pairs by; imaging analysts using specialised software [semi-automated], and MSmetrix [fully-automated]. Data was presented in two separate reports; local QMRI (semi-automated) and centralised QMRI (MSmetrix). Questionnaires were completed by the same neurologist for each subject using clinical data and standard MRI and QMRI reports.

Results

31 relapsing-MS patients (77.4% female), with baseline age 42.14 [10.70] years, disease duration 7.68 [4.89] years and EDSS score 1.40 (1.36), were evaluated. Injectable, oral and infusion DMTs were administered in 29.0%, 61.3% and 9.7% of patients respectively. According to questionnaire responses, 83.9% were predicted to have stable disease over the next year based on clinical reports alone and 67.7% with the addition of QMRI report data. DMT change would be considered in 16.1% based on clinical reports and 32.3% with QMRI report inclusion. Earlier clinical ±MRI follow up was considered in 51.6% (MRI only 41.9%;both 9.7%) when QMRI reports were reviewed.

Conclusion

This preliminary retrospective study indicates that QMRI report data has the potential to influence clinical decision-making in relapsing-MS patients on DMT regarding disease stability assessment, therapy change contemplation, and consideration of earlier follow-up. This work supports a role for formal QMRI analysis and reporting as a clinical-decision support system in MS.

049 Lower stimulus contrast is associated with stronger multifocal visual evoked potential signals

Introduction

Visual evoked potentials (VEPs) are used to assess the visual system in neuro-ophthalmological diseases such as multiple sclerosis (MS). Axonal damage, and subsequent reduction of VEP amplitude, is considered central to the development of disability. To obtain the strongest signal possible, high contrast (HC) pattern-reversing checkboard stimuli are routinely used to induce cortical electrical potentials. Low contrast (LC) visual acuity assessment is better than HC visual acuity testing in detecting MS-related visual impairment. This study aims to determine if the use of LC stimuli in multifocal VEPs improves detection visual dysfunction in patients with MS.

Methods

14 MS patients (8 with history of optic neuritis) and 12 healthy controls had HC (Michelson 98%) and LC (Michelson 22%) multifocal VEP performed. The VEP signal from the 56 individual sectors was transformed into absolute values and averaged. The area under the curve (AUC) for each individual’s mfVEP was determined for HC and LC stimuli. Subsequently, 5 healthy controls with best-corrected vision ≥20/20 underwent mfVEP assessment at 8 different contrast levels (Michelson contrast 8%, 15%, 22%–31% 41%, 53%, 64%, 98%).

Results

There was no significant difference in the mfVEP AUC between MS patients (including 10 ON eyes only) and controls for HC, LC or the difference between HC and LC stimuli. Part 2 of the study demonstrated the relationship between stimulus contrast and signal strength. All subjects had a roughly parabolic relationship with AUC greatest at mid-level contrast. Averaged data of all subjects showed a parabolic relationship characterised by y=-2834.1x2 – 2127.1x+3144.2, R²=0.911.

Conclusion

Assessing reduction in mfVEP signal strength with LC stimuli requires an appropriate HC comparator stimulus. This study may also provide rationale for clinical mfVEP studies to use lower contrast stimuli to increase the signal strength of the study.

113 Rituximab and maintenance mycophenolate mofetil for treatment of refractory ANTI-N-METHYL-D-ASPARTATE-receptor (NMDAR) encephalitis

Introduction

NMDAR encephalitis is an autoimmune condition with antibodies to the NR1 subunit of the NMDAR. It has a variable clinical presentation with behavioural and psychiatric symptoms. There is frequently a relapsing course. A known association exists with tumours, particularly ovarian teratoma. Cases which are not associated with tumour often fail first line therapy. As such, therapy for this disease can be challenging and involves a spectrum of immunotherapy. Rituximab is widely considered to be second line treatment for this illness. We present two cases of refractory anti-NMDAR encephalitis.

Cases

Both patients were confirmed antibody positive in the serum and cerebral spinal fluid. There was no tumour identified on whole body positron emission tomography and transvaginal pelvic ultrasound. Each patient was initially treated with first line therapy of intravenous immunoglobulin, plasmapheresis and methylprednisolone with limited symptomatic improvement. Second line therapy of two doses of rituximab was administered intravenously two weeks apart at a dose of 1000 mg. Mycophenolate mofetil was used at a dose of 1000 mg twice daily to minimise B-cell reconstitution. Response to treatment was monitored with measurement of CD 19+ Pan B cells in peripheral blood and clinical assessment by the consultant liaison psychiatry service. Both patients demonstrated significant response with undetectable CD 19+ Pan B cells on serial testing and sustained clinical improvement in initial behavioural symptoms.

Conclusion

In patients with anti-NMDAR encephalitis, rituximab combined with maintenance mycophenolate mofetil may be an effective treatment.

005 Filling in the gaps: precision MRI reporting in multiple sclerosis clinical practice

Introduction

Clinical multiple sclerosis (MS) magnetic resonance imaging (MRI) brain reports provide important information to neurologists. The quantitative data reported varies between centres and radiologists. Structured MRI reporting and formal quantitative MRI (QMRI) analysis may assist clinicians with patient management. The objective is to compare quantitative data derived from standard clinical reports, structured neuroradiologist reviews, local QMRI analyses and fully-automated MSmetrix QMRI analyses, in a longitudinal clinical MS cohort.

Methods

Clinical brain MRI scans separated by one-year minimum, from the same patient on the same scanner, were evaluated. Quantitative information was extracted from the clinical reports and structured neuroradiologist reviews. MRI scan-pairs were analysed locally by imaging-analysts and centrally by MSmetrix.

Results

50 MS patients, baseline age 39.02 (9.06) years, disease duration 9.11 (6.88) years and Expanded Disability Status Scale score 1.91 (1.62), were included. Compared to clinical reports, structured neuroradiologist reviews provided increased semi-/quantitative data; baseline T2 and T1 lesion burden (50% vs 100%; 2% vs 100%), baseline brain volume-loss (BVL; 72% vs 100%), new T1 lesions (0% vs 100%), regional brain atrophy (BA; 20% vs 100%). Lesion and brain volumes were not provided in radiology reports/reviews. Comparison of local and central QMRI revealed moderate-strong Pearson correlations for most metrics; Intra-class correlations varied more widely. Statistical consistency existed across all methods in detecting new T2 lesions. Radiologist-identified baseline BVL was associated with lower quantitatively-measured brain volumes. Local QMRI longitudinal BA rates >0.4% and >0.8%, were 48% and 26% respectively. Neuroradiologist review identified BA in 12%.

Conclusion

Structured neuroradiology review provided additional quantitative information over standard clinical reports. Quantitative data measured using local and MSmetrix pipelines were generally well associated but are not interchangeable. Longitudinal whole brain and regional atrophy is not reliably identified by radiologists and QMRI analysis provides a clear advantage in this regard. Structured reporting, and formal QMRI analysis, provide additional quantitative MRI data that may assist clinical decision-making in MS.

015 Predicting a diagnosis of pathologically confirmed vasculitic neuropathy

Introduction

Nerve biopsy remains the gold standard to diagnose vasculitic neuropathy. Conversely, biopsy has imperfect sensitivity and entails risks associated with an invasive procedure. Methods to improve diagnostic accuracy remain important considerations given the severity of the disease, added with the risks associated with subsequent therapy, particularly in ill-defined cases.

Methods

Clinical, laboratory and neurophysiological parameters were analysed for all patients who subsequently underwent biopsy. Nerve and muscle biopsy reports were assigned pathologic categories of definite, probable, possible or absent vasculitis using standard guidelines. Correlations were assessed between pre-biopsy parameters and subsequent diagnosis of definite or probable vasculitic neuropathy (pathologically confirmed vasculitis).

Results

From a cohort of 207 patients who underwent nerve biopsy over 21 months, 70 were suspected of having vasculitic neuropathy prior to biopsy. Of the 70 patients, vasculitis was confirmed as definite (11.4%), probable (15.7%) or possible (10.0%) on neuropathological assessment. The most sensitive parameters for pathologically confirmed vasculitis were the presence of sensorimotor neuropathy (78%) and axonal neuropathy (67%) on nerve conduction studies (NCS) in the overall cohort. Pathologically absent vasculitis was most prevalent in patients with normal NCS (90%), chronic, symmetric symptoms (86%) and demyelinating findings on NCS (79%). The parameters with the strongest associations with pathologically confirmed vasculitis were positive autoantibody serology (50.0% vs 21.1%, p<0.01), anti-neutrophil cytoplasmic antibody (27.3% vs 6.4%, p<0.01), anti-myeloperoxidase antibody (22.7% vs 1.8%, p<0.005) and rheumatoid factor (22.7% vs 2.8%, p<0.005). In patients suspected to have vasculitis, 83.3% of anti-myeloperoxidase antibody positive patients had pathologically confirmed vasculitis. In patients not suspected to have vasculitis, acute symptoms had the strongest association with pathologically confirmed vasculitis (36.4% vs 10.5%, p<0.05).

Conclusion

Specific characteristics of symptoms at the time of presentation, combined with the presence of autoantibodies and neurophysiological abnormalities, were predictive of a tissue diagnosis of vasculitic neuropathy.

White matter tract-specific quantitative analysis in multiple sclerosis: Comparison of optic radiation reconstruction techniques

The posterior visual pathway is commonly affected by multiple sclerosis (MS) pathology that results in measurable clinical and electrophysiological impairment. Due to its highly structured retinotopic mapping, the visual pathway represents an ideal substrate for investigating patho-mechanisms in MS. Therefore, a reliable and robust imaging segmentation method for in-vivo delineation of the optic radiations (OR) is needed. However, diffusion-based tractography approaches, which are typically used for OR segmentation are confounded by the presence of focal white matter lesions. Current solutions require complex acquisition paradigms and demand expert image analysis, limiting application in both clinical trials and clinical practice. In the current study, using data acquired in a clinical setting on a 3T scanner, we optimised and compared two approaches for optic radiation (OR) reconstruction: individual probabilistic tractography-based and template-based methods. OR segmentation results were applied to subjects with MS and volumetric and diffusivity parameters were compared between OR segmentation techniques. Despite differences in reconstructed OR volumes, both OR lesion volume and OR diffusivity measurements in MS subjects were highly comparable using optimised probabilistic tractography-based, and template-based, methods. The choice of OR reconstruction technique should be determined primarily by the research question and the nature of the available dataset. Template-based approaches are particularly suited to the semi-automated analysis of large image datasets and have utility even in the absence of dMRI acquisitions. Individual tractography methods, while more complex than template based OR reconstruction, permit measurement of diffusivity changes along fibre bundles that are affected by specific MS lesions or other focal pathologies.

Progressive inner nuclear layer dysfunction in non-optic neuritis eyes in MS

OBJECTIVE

To investigate primary retinal functional changes in non-optic neuritis (ON) eyes of patients with MS by full-field electroretinography (ERG).

METHODS

Seventy-seven patients with relapsing-remitting MS with no history of clinical ON in at least 1 eye and 30 healthy controls were recruited in the cohort study. Full-field ERGs were recorded, and retinal optical coherence tomography scans were performed to assess the thicknesses of peripapillary retinal nerve fiber layer (RNFL) and retinal ganglion cell layer-inner plexiform layer (GCL-IPL). Annual MRI scans were also carried out to evaluate the disease activity in the brain. Patients were followed up for 3 years.

RESULTS

At baseline, a delayed b-wave peak time was observed in the cone response (p < 0.001), which was associated with the thicknesses of RNFL and GCL-IPL. The peak time of the delayed b-wave also correlated with the Expanded Disability Status Scale, T2 lesion volume, and disease duration. During the 3-year follow-up, progressive ERG amplitude reduction was observed (both a- and b-waves, p < 0.05). There was a correlation between the b-wave amplitude reduction and longitudinal RNFL loss (p = 0.001). However, no correlation was found between longitudinal ERG changes and disease activity in the brain.

CONCLUSIONS

This study demonstrated progressive inner nuclear layer dysfunction in MS. The borderline a-wave changes suggested some outer retinal dysfunction as well. The correlation between full-field ERG changes and retinal ganglion cell loss suggested that there might be subclinical retinal pathology in MS affecting both outer and inner retinal layers.

Evidence of progressive tissue loss in the core of chronic MS lesions: A longitudinal DTI study

Objective

Using diffusion tensor imaging (DTI), we examined chronic stable MS lesions, peri-lesional white matter (PLWM) and normal appearing white matter (NAWM) in patients with relapsing-remitting multiple sclerosis (RRMS) for evidence of progressive tissue destruction and evaluated whether diffusivity change is associated with conventional MRI parameters and clinical findings.

Method

Pre- and post-gadolinium T1, T2 and DTI images were acquired from 55 consecutive RRMS patients at baseline and 42.3 ± 9.7 months later. Chronic stable T2 lesions of sufficient size were identified in 43 patients (total of 134 lesions). Diffusivity parameters such as axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD) and fractional anisotropy (FA) were compared at baseline and follow-up. MRI was also performed in 20 normal subjects of similar age and gender.

Results

Within the core of chronic MS lesions the diffusion of water molecules significantly increased over the follow-up period, while in NAWM all diffusivity indices remained stable. Since increase of AD and RD in lesional core was highly concordant, indicating isotropic nature of diffusivity change, and considering potential effect of crossing fibers on directionally-selective indices, only MD, a directionally-independent measure, was used for further analysis. The significant increase of MD in the lesion core during the follow-up period (1.29 ± 0.19 μm2/ms and 1.34 ± 0.20 μm2/ms at baseline and follow-up respectively, P < 0.0001) was independent of age or disease duration, total brain lesion volume or new lesion activity, lesion size or location and baseline tissue damage (T1 hypointensity). Change of MD in the lesion core, however, was associated with progressive brain atrophy (r = 0.47, P = 0.002). A significant gender difference was also observed: the MD change in male patients was almost twice that of female patients (0.030 ± 0.04 μm2/ms and 0.058 ± 0.03 μm2/ms in female and male respectively, P = 0.01). Sub-analysis of lesions with lesion-free surrounding revealed the largest MD increase in the lesion core, while MD progression gradually declined towards PLWM. MD in NAWM remained stable over the follow-up period.

Conclusion

The significant increase of isotropic water diffusion in the core of chronic stable MS lesions likely reflects gradual, self-sustained tissue destruction in demyelinated white matter that is more aggressive in males.

Exosomal microRNA signatures in multiple sclerosis reflect disease status

Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). There is currently no single definitive test for MS. Circulating exosomes represent promising candidate biomarkers for a host of human diseases. Exosomes contain RNA, DNA, and proteins, can cross the blood-brain barrier, and are secreted from almost all cell types including cells of the CNS. We hypothesized that serum exosomal miRNAs could present a useful blood-based assay for MS disease detection and monitoring. Exosome-associated microRNAs in serum samples from MS patients (n = 25) and matched healthy controls (n = 11) were profiled using small RNA next generation sequencing. We identified differentially expressed exosomal miRNAs in both relapsing-remitting MS (RRMS) (miR-15b-5p, miR-451a, miR-30b-5p, miR-342-3p) and progressive MS patient sera (miR-127-3p, miR-370-3p, miR-409-3p, miR-432-5p) in relation to controls. Critically, we identified a group of nine miRNAs (miR-15b-5p, miR-23a-3p, miR-223-3p, miR-374a-5p, miR-30b-5p, miR-433-3p, miR-485-3p, miR-342-3p, miR-432-5p) that distinguished relapsing-remitting from progressive disease. Eight out of nine miRNAs were validated in an independent group (n = 11) of progressive MS cases. This is the first demonstration that microRNAs associated with circulating exosomes are informative biomarkers not only for the diagnosis of MS, but in predicting disease subtype with a high degree of accuracy.

Incidence and prevalence of NMOSD in Australia and New Zealand

OBJECTIVES

We have undertaken a clinic-based survey of neuromyelitis optica spectrum disorders (NMOSDs) in Australia and New Zealand to establish incidence and prevalence across the region and in populations of differing ancestry.

BACKGROUND

NMOSD is a recently defined demyelinating disease of the central nervous system (CNS). The incidence and prevalence of NMOSD in Australia and New Zealand has not been established.

METHODS

Centres managing patients with demyelinating disease of the CNS across Australia and New Zealand reported patients with clinical and laboratory features that were suspicious for NMOSD. Testing for aquaporin 4 antibodies was undertaken in all suspected cases. From this group, cases were identified who fulfilled the 2015 Wingerchuk diagnostic criteria for NMOSD. A capture-recapture methodology was used to estimate incidence and prevalence, based on additional laboratory identified cases.

RESULTS

NMOSD was confirmed in 81/170 (48%) cases referred. Capture-recapture analysis gave an adjusted incidence estimate of 0.37 (95% CI 0.35 to 0.39) per million per year and a prevalence estimate for NMOSD of 0.70 (95% CI 0.61 to 0.78) per 100 000. NMOSD was three times more common in the Asian population (1.57 (95% CI 1.15 to 1.98) per 100 000) compared with the remainder of the population (0.57 (95% CI 0.50 to 0.65) per 100 000). The latitudinal gradient evident in multiple sclerosis was not seen in NMOSD.

CONCLUSIONS

NMOSD incidence and prevalence in Australia and New Zealand are comparable with figures from other populations of largely European ancestry. We found NMOSD to be more common in the population with Asian ancestry.

Two Time Point MS Lesion Segmentation in Brain MRI: An Expectation-Maximization Framework

Purpose: Lesion volume is a meaningful measure in multiple sclerosis (MS) prognosis. Manual lesion segmentation for computing volume in a single or multiple time points is time consuming and suffers from intra and inter-observer variability. Methods: In this paper, we present MSmetrix-long: a joint expectation-maximization (EM) framework for two time point white matter (WM) lesion segmentation. MSmetrix-long takes as input a 3D T1-weighted and a 3D FLAIR MR image and segments lesions in three steps: (1) cross-sectional lesion segmentation of the two time points; (2) creation of difference image, which is used to model the lesion evolution; (3) a joint EM lesion segmentation framework that uses output of step (1) and step (2) to provide the final lesion segmentation. The accuracy (Dice score) and reproducibility (absolute lesion volume difference) of MSmetrix-long is evaluated using two datasets. Results: On the first dataset, the median Dice score between MSmetrix-long and expert lesion segmentation was 0.63 and the Pearson correlation coefficient (PCC) was equal to 0.96. On the second dataset, the median absolute volume difference was 0.11 ml. Conclusions: MSmetrix-long is accurate and consistent in segmenting MS lesions. Also, MSmetrix-long compares favorably with the publicly available longitudinal MS lesion segmentation algorithm of Lesion Segmentation Toolbox.

Neurological deficit following stereotactic radiosurgery for trigeminal neuralgia

We report a unique case of neurological deficit from late onset multiple sclerosis (MS), in a 65-year-old woman, after stereotactic radiosurgery (SRS) for trigeminal neuralgia (TN). At 3.5months post-SRS for TN, the patient developed ataxia and left leg paraesthesiae and brain MRI showed altered signal and enhancement in the vicinity of the right trigeminal root entry zone (REZ). The symptoms remitted following treatment with intravenous methylprednisolone, however, 10months post-SRS, the patient developed gait ataxia and left lower limb weakness. MRI showed persistent T2 changes at the REZ and multiple new non-enhancing white matter lesions in the cerebrum and spinal cord; and oligoclonal bands were present in the cerebrospinal fluid but not serum. A diagnosis of multiple sclerosis (MS) was made. This report raises the issue of whether the risk of radiation-induced toxicity is increased in patients with MS treated with SRS. We hypothesise that breakdown in the blood brain barrier secondary to the radiosurgery may have triggered a vigorous local inflammatory response.

Progressive Loss of Retinal Ganglion Cells and Axons in Nonoptic Neuritis Eyes in Multiple Sclerosis: A Longitudinal Optical Coherence Tomography Study

PURPOSE

To examine the rate of retinal ganglion cell (RGC) layer and retinal nerve fiber layer (RNFL) changes in nonoptic neuritis (NON) eyes of relapsing remitting multiple sclerosis (RRMS) patients, and to find a specific imaging parameter useful for identifying disease progression.

METHODS

Forty-five consecutive RRMS patients and 20 age- and sex-matched healthy subjects were enrolled. All patients were followed up for 3 years with annual optical coherence tomography (OCT) scans, which included a peripapillary ring scan protocol for RNFL analysis and a macular radial star-like scan to obtain RGC/inner plexiform layer (IPL) thickness measures. Healthy controls were scanned twice, 3 years apart.

RESULTS

Retinal ganglion cell/inner plexiform layer and temporal RNFL (tRNFL) demonstrated highly significant thinning (P < 0.01), but all nasal segments and global RNFL (gRNFL) were not significantly different from normal controls. While receiver operating characteristics (ROC) analysis showed no advantage of RGC/IPL over tRNFL in cross-sectional detection of thinning, cut-off point based of fifth percentile in healthy controls demonstrated higher rate of abnormality for RGC/IPL. There was a significant progressive loss of RGC/IPL and tRNFL during the follow-up period. The largest thickness reduction was observed in tRNFL. ROC analysis demonstrated that tRNFL provided better sensitivity/specificity for detecting change over time than RGC/IPL (area under the curve [AUC] 0.78 vs. 0.52), which was confirmed by higher detection rate when 95th percentile of progression in healthy controls was used as a cut-off.

CONCLUSIONS

This study confirmed significant thinning of RGC/IPL and tRNFL in NON eyes of RRMS patients. Progressive losses were more apparent on tRNFL, while RGC/IPL showed less change over the follow-up period.

Defining secondary progressive multiple sclerosis

A number of studies have been conducted with the onset of secondary progressive multiple sclerosis as an inclusion criterion or an outcome of interest. However, a standardized objective definition of secondary progressive multiple sclerosis has been lacking. The aim of this work was to evaluate the accuracy and feasibility of an objective definition for secondary progressive multiple sclerosis, to enable comparability of future research studies. Using MSBase, a large, prospectively acquired, global cohort study, we analysed the accuracy of 576 data-derived onset definitions for secondary progressive multiple sclerosis and first compared these to a consensus opinion of three neurologists. All definitions were then evaluated against 5-year disease outcomes post-assignment of secondary progressive multiple sclerosis: sustained disability, subsequent sustained progression, positive disability trajectory, and accumulation of severe disability. The five best performing definitions were further investigated for their timeliness and overall disability burden. A total of 17 356 patients were analysed. The best definition included a 3-strata progression magnitude in the absence of a relapse, confirmed after 3 months within the leading Functional System and required an Expanded Disability Status Scale step ≥4 and pyramidal score ≥2. It reached an accuracy of 87% compared to the consensus diagnosis. Seventy-eight per cent of the identified patients showed a positive disability trajectory and 70% reached significant disability after 5 years. The time until half of all patients were diagnosed was 32.6 years (95% confidence interval 32-33.6) after disease onset compared with the physicians' diagnosis at 36 (35-39) years. The identified patients experienced a greater disease burden [median annualized area under the disability-time curve 4.7 (quartiles 3.6, 6.0)] versus non-progressive patients [1.8 (1.2, 1.9)]. This objective definition of secondary progressive multiple sclerosis based on the Expanded Disability Status Scale and information about preceding relapses provides a tool for a reproducible, accurate and timely diagnosis that requires a very short confirmation period. If applied broadly, the definition has the potential to strengthen the design and improve comparability of clinical trials and observational studies in secondary progressive multiple sclerosis.

Diffusivity in multiple sclerosis lesions: At the cutting edge?

Background

Radial Diffusivity (RD) has been suggested as a promising biomarker associated with the level of myelination in MS lesions. However, the level of RD within the lesion is affected not only by loss of myelin sheaths, but also by the degree of tissue destruction. This may lead to exaggeration of diffusivity measures, potentially masking the effect of remyelination.

Objective

To test the hypothesis that the T2 hyperintense lesion edge that extends beyond the T1 hypointense lesion core is less affected by tissue loss, and therefore a more appropriate target for imaging biomarker development targeting de- and re-myelination.

Method

Pre- and post-gadolinium (Gd) enhanced T1, T2 and DTI images were acquired from 75 consecutive RRMS patients. The optic radiation (OR) was identified in individual patients using a template-based method. T2 lesions were segmented into T1-hypointense and T1-isointense areas and lesion masks intersected with the OR. Average Radial, Axial and Mean diffusivity (RD, AD and MD) and fractional anisotropy (FA) were calculated for lesions of the entire brain and the OR. In addition, Gd enhancing lesions were excluded from the analysis.

Results

86% of chronic T2 lesions demonstrated hypointense areas on T1-weighted images, which typically occupied the central part of each T2 lesion, taking about 40% of lesional volume. The T1-isointense component of the T2 lesion was most commonly seen as a peripheral ring of relatively constant thickness (“T2-rim”). While changes of diffusivity between adjacent normal appearing white matter and the “T2-rim” demonstrated a disproportionally high elevation of RD compare to AD, the increase of water diffusion was largely isointense between the “T2-rim” and T1-hypointense parts of the lesion.

Conclusion

Distinct patterns of diffusivity within the central and peripheral components of MS lesions suggest that axonal loss dominates in the T1 hypointense core. The effects of de/remyelination may be more readily detected in the “T2-rim”, where there is relative preservation of structural integrity. Identifying and separating those patterns has an important implication for clinical trials of both neuroprotective and, in particular, remyelinating agents.

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Distinct patterns of diffusivity within the central and peripheral components of MS lesions were identified.

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Axonal loss is likely to dominate the T1 hypointense core.

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The effects of de/remyelination may be more readily detected in the “T2-rim”.

Automated brain volumetrics in multiple sclerosis: a step closer to clinical application

BACKGROUND

Whole brain volume (WBV) estimates in patients with multiple sclerosis (MS) correlate more robustly with clinical disability than traditional, lesion-based metrics. Numerous algorithms to measure WBV have been developed over the past two decades. We compare Structural Image Evaluation using Normalisation of Atrophy-Cross-sectional (SIENAX) to NeuroQuant and MSmetrix, for assessment of cross-sectional WBV in patients with MS.

METHODS

MRIs from 61 patients with relapsing-remitting MS and 2 patients with clinically isolated syndrome were analysed. WBV measurements were calculated using SIENAX, NeuroQuant and MSmetrix. Statistical agreement between the methods was evaluated using linear regression and Bland-Altman plots. Precision and accuracy of WBV measurement was calculated for (1) NeuroQuant versus SIENAX and (2) MSmetrix versus SIENAX.

RESULTS

Precision (Pearson's r) of WBV estimation for NeuroQuant and MSmetrix versus SIENAX was 0.983 and 0.992, respectively. Accuracy (Cb) was 0.871 and 0.994, respectively. NeuroQuant and MSmetrix showed a 5.5% and 1.0% volume difference compared with SIENAX, respectively, that was consistent across low and high values.

CONCLUSIONS

In the analysed population, NeuroQuant and MSmetrix both quantified cross-sectional WBV with comparable statistical agreement to SIENAX, a well-validated cross-sectional tool that has been used extensively in MS clinical studies.

Plasma levels of endothelial and B-cell-derived microparticles are restored by fingolimod treatment in multiple sclerosis patients

BACKGROUND

No molecular marker can monitor disease progression and treatment efficacy in multiple sclerosis (MS). Circulating microparticles represent a potential snapshot of disease activity at the blood brain barrier.

OBJECTIVES AND METHODS

To profile plasma microparticles by flow cytometry in MS and determine how fingolimod could impact endothelial microparticles production.

RESULTS

In non-treated MS patients compared to healthy and fingolimod-treated patients, endothelial microparticles were higher, while B-cell-microparticle numbers were lower. Fingolimod dramatically reduced tumour necrosis factor (TNF)-induced endothelial microparticle release in vitro.

CONCLUSION

Fingolimod restored dysregulated endothelial and B-cell-microparticle numbers, which could serve as a biomarker in MS.

Migration and multiple sclerosis in immigrants from United Kingdom and Ireland to Australia: a reassessment. III: risk of multiple sclerosis in UKI immigrants and Australian-born in Hobart, Tasmania

Our previous work suggested that migrants from the United Kingdom and Ireland (UKI) to Australia who left their home country at a young age had a longer interval between immigration and onset and likely acquired MS in Australia. In the present study, we reassessed Australian-born cases of MS identified in Hobart, Tasmania, a relatively high-risk zone, in our 1981 survey and compared these with cases of MS in UKI immigrants incident in Australia. The incidence of MS in Australian-born residents rose from 1.63 per 100,000 in 1941-1965 to 3.48 per 100,000 in 1966-1981. The bulk of UKI immigrants who developed MS in Australia migrated after the age of 15 years, and likely acquired their disease in the UKI. The mean interval from immigration to onset differed significantly (p < 0.01) between those migrating before (22 years) versus after (6 years) the age of 15, suggesting acquisition of MS in Australia in the former group. Identified environmental risk factors such as smoking, sunlight and exposure to Epstein-Barr virus do not fully account for the epidemiology of multiple sclerosis. The apparent introduction of MS into Hobart from the mid-1940s on could provide circumstantial support for the theory that MS is a transmissible disease.

Progressive Injury in Chronic Multiple Sclerosis Lesions Is Gender-Specific: A DTI Study

Objective

To evaluate the longitudinal integrity of white matter tracts in patients with relapsing remitting multiple sclerosis (RRMS) as determined by changes in diffusivity indices of lesional and non-lesional white matter in the optic radiation over 12 months.

Methods

The optic radiation (OR) was identified in sixty RRMS patients using probabilistic tractography. MS lesions were segmented on FLAIR T2 images and a lesion mask was intersected with the co-registered OR. Lesions within the OR were identified in 39 patients. Voxel-based analysis of axial diffusivity (AD) and radial diffusivity (RD) within OR lesions and non-lesional normal appearing white matter (NAWM) was performed at baseline and 12 months in 34 patients (five patients excluded due to new OR lesions).

Results

Both RD and AD demonstrated much higher values within the lesions compared with non-lesional NAWM. There was a significant (p<0.001) increase of lesional AD and RD during the follow-up period. This increase, however, was driven almost entirely by the male cohort, in which a significantly greater change in both AD (M-2.7%, F-0.9%) and RD (M-4.6%, F-0.7%) was observed during the follow-up period. Non-lesional NAWM also demonstrated an increase in both AD and RD, albeit on a much lesser scale (1.0% and 0.6% respectively). In contradistinction to lesions, the diffusivity change in non-lesional NAWM was similar between sexes.

Conclusions

The evolution of AD and RD in chronic MS lesions over 12 months suggests ongoing inflammatory demyelinating activity accompanied by axonal loss. In addition, our findings are consistent with the recently observed trend of more rapid clinical progression in males and establish a potential in vivo biomarker of gender dichotomy by demonstrating a significantly faster rate of microstructural change in the chronic lesions of male patients with MS.

The corpus callosum in the diagnosis of multiple sclerosis and other CNS demyelinating and inflammatory diseases

Lesions in the corpus callosum (CC) are important radiological clues to the diagnosis of multiple sclerosis (MS), but may also occur in other neuroinflammatory and non-neuroinflammatory conditions. In this article, we discuss the radiological features of lesions within the CC in MS and other central nervous system inflammatory and acquired demyelinating diseases. An understanding of the appearance and location of lesions in the CC is important not only for accurate diagnosis and treatment of these various conditions, but as it also provides insights into pathogenesis.

Chronic inflammatory demyelinating polyradiculoneuropathy: from pathology to phenotype

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an inflammatory neuropathy, classically characterised by a slowly progressive onset and symmetrical, sensorimotor involvement. However, there are many phenotypic variants, suggesting that CIDP may not be a discrete disease entity but rather a spectrum of related conditions. While the abiding theory of CIDP pathogenesis is that cell-mediated and humoral mechanisms act together in an aberrant immune response to cause damage to peripheral nerves, the relative contributions of T cell and autoantibody responses remain largely undefined. In animal models of spontaneous inflammatory neuropathy, T cell responses to defined myelin antigens are responsible. In other human inflammatory neuropathies, there is evidence of antibody responses to Schwann cell, compact myelin or nodal antigens. In this review, the roles of the cellular and humoral immune systems in the pathogenesis of CIDP will be discussed. In time, it is anticipated that delineation of clinical phenotypes and the underlying disease mechanisms might help guide diagnostic and individualised treatment strategies for CIDP.

Tablet-based screening improves continence management in multiple sclerosis

Objective

To investigate whether electronic continence questionnaires aid early identification and optimizes management of sphincter dysfunction in a multiple sclerosis clinic.

Methods

A custom designed, tablet-based cross-platform software tool was designed to capture validated multiple sclerosis (MS) patient-reported outcomes. An unselected cohort of MS patients from a tertiary referral clinic completed electronic tablet-based versions of the Bladder Control Scale (BLCS) and the Bowel Control Scale in the waiting room. Data were captured wirelessly “on-the-fly” and stored in a deidentified, secure database; and individual questionnaire results were immediately available to the treating neurologist in the electronic medical record. Scores of ≥2 on either questionnaire generated an automated electronic referral to the clinic MS continence nurse (MS CN).

Results

One hundred and fifty-seven MS patients completed a total of 184 electronic continence test sets and on two occasions only the BLCS was completed. An automatic electronic referral for formal continence review was generated 128 times in 108 patients. Fifty-seven formal continence assessments were undertaken by the MS CN following automated referral. All reviews resulted in at least one clinical intervention being made.

Interpretation

Tablet-based data capture and automated continence referral using this software tool is an efficient, sensitive, and feasible method of screening MS patients for bladder and bowel dysfunction. Concordance with the results of formal continence assessment in this pilot study validates the use of this technology as a screening tool.

Decoding diffusivity in multiple sclerosis: analysis of optic radiation lesional and non-lesional white matter

Objectives

Diffusion tensor imaging (DTI) has been suggested as a new promising tool in MS that may provide greater pathological specificity than conventional MRI, helping, therefore, to elucidate disease pathogenesis and monitor therapeutic efficacy. However, the pathological substrates that underpin alterations in brain tissue diffusivity are not yet fully delineated. Tract-specific DTI analysis has previously been proposed in an attempt to alleviate this problem. Here, we extended this approach by segmenting a single tract into areas bound by seemingly similar pathological processes, which may better delineate the potential association between DTI metrics and underlying tissue damage.

Method

Several compartments were segmented in optic radiation (OR) of 50 relapsing-remitting MS patients including T2 lesions, proximal and distal parts of fibers transected by lesion and fibers with no discernable pathology throughout the entire length of the OR.

Results

Asymmetry analysis between lesional and non-lesional fibers demonstrated a marked increase in Radial Diffusivity (RD), which was topographically limited to focal T2 lesions and potentially relates to the lesional myelin loss. A relative elevation of Axial Diffusivity (AD) in the distal part of the lesional fibers was observed in a distribution consistent with Wallerian degeneration, while diffusivity in the proximal portion of transected axons remained normal. A moderate, but significant elevation of RD in OR non-lesional fibers was strongly associated with the global (but not local) T2 lesion burden and is probably related to microscopic demyelination undetected by conventional MRI.

Conclusion

This study highlights the utility of the compartmentalization approach in elucidating the pathological substrates of diffusivity and demonstrates the presence of tissue-specific patterns of altered diffusivity in MS, providing further evidence that DTI is a sensitive marker of tissue damage in both lesions and NAWM. Our results suggest that, at least within the OR, parallel and perpendicular diffusivities are affected by tissue restructuring related to distinct pathological processes.

Axonal conduction in multiple sclerosis: A combined magnetic resonance imaging and electrophysiological study of the medial longitudinal fasciculus

Objective:

The objective of this paper is to inform the pathophysiology of medial longitudinal fasciculus (MLF) axonal dysfunction in patients with internuclear ophthalmoplegia (INO) due to multiple sclerosis (MS), and develop a composite structural-functional biomarker of axonal and myelin integrity in this tract.

Methods:

Eighteen patients with definite MS and clinically suspected INO underwent electrical vestibular stimulation and search-coil eye movement recording. Components of the electrically evoked vestibulo-ocular reflex (eVOR) were analyzed to probe the latency and fidelity of MLF axonal conduction. The MLF and T2-visible brainstem lesions were defined by high-resolution MRI. White matter integrity was determined by diffusion-weighted imaging metrics.

Results:

eVOR onset latency was positively correlated with MLF lesion length (left: r = 0.66, p = 0.004; right: r = 0.75, p = 0.001). The mean conduction velocity (±SD) within MLF lesions was estimated at 2.72 (±0.87) m/s. eVOR onset latency correlated with normalized axial diffusivity ( r = 0.66, p < 0.001) and fractional anisotropy ( r = 0.44, p = 0.02) after exclusion of cases with ipsilateral vestibular root entry zone lesions.

Conclusions:

Axonal conduction velocity through lesions involving the MLF was reduced below levels predicted for natively myelinated and remyelinated axons. Composite in vivo biomarkers enable delineation of axonal from myelin processes and may provide a crucial role in assessing efficacy of novel reparative therapies in MS.

Conventional and advanced imaging in neuromyelitis optica

Myelitis and optic neuritis are prototypic clinical presentations of both multiple sclerosis and neuromyelitis optica. Once considered a subtype of multiple sclerosis, neuromyelitis optica, is now known to have a discrete pathogenesis in which antibodies to the water channel, aquaporin 4, play a critical role. Timely differentiation of neuromyelitis optica from MS is imperative, determining both prognosis and treatment strategy. Early, aggressive immunosuppression is required to prevent the accrual of severe disability in neuromyelitis optica; conversely, MS-specific therapies may exacerbate the disease. The diagnosis of neuromyelitis optica requires the integration of clinical, MR imaging, and laboratory data, but current criteria are insensitive and exclude patients with limited clinical syndromes. Failure to recognize the expanding spectrum of cerebral MR imaging patterns associated with aquaporin 4 antibody seropositivity adds to diagnostic uncertainty in some patients. We present the state of the art in conventional and nonconventional MR imaging in neuromyelitis optica and review the place of neuroimaging in the diagnosis, management, and research of the condition.

Therapeutic approaches to disease modifying therapy for multiple sclerosis in adults: an Australian and New Zealand perspective: part 1 historical and established therapies. MS Neurology Group of the Australian and New Zealand Association of Neurologists

Multiple sclerosis (MS) is a potentially life-changing immune mediated disease of the central nervous system. Until recently, treatment has been largely confined to acute treatment of relapses, symptomatic therapies and rehabilitation. Through persistent efforts of dedicated physicians and scientists around the globe for 160 years, a number of therapies that have an impact on the long term outcome of the disease have emerged over the past 20 years. In this three part series we review the practicalities, benefits and potential hazards of each of the currently available and emerging treatment options for MS. We pay particular attention to ways of abrogating the risks of these therapies and provide advice on the most appropriate indications for using individual therapies. In Part 1 we review the history of the development of MS therapies and its connection with the underlying immunobiology of the disease. The established therapies for MS are reviewed in detail and their current availability and indications in Australia and New Zealand are summarised. We examine the evidence to support their use in the treatment of MS.

Therapeutic approaches to disease modifying therapy for multiple sclerosis in adults: an Australian and New Zealand perspective: part 3 treatment practicalities and recommendations. MS Neurology Group of the Australian and New Zealand Association of Neurologists

In this third and final part of our review of multiple sclerosis (MS) treatment we look at the practical day-to-day management issues that are likely to influence individual treatment decisions. Whilst efficacy is clearly of considerable importance, tolerability and the potential for adverse effects often play a significant role in informing individual patient decisions. Here we review the issues surrounding switching between therapies, and the evidence to assist guiding the choice of therapy to change to and when to change. We review the current level of evidence with regards to the management of women in their child-bearing years with regards to recommendations about treatment during pregnancy and whilst breast feeding. We provide a summary of recommended pre- and post-treatment monitoring for the available therapies and review the evidence with regards to the value of testing for antibodies which are known to be neutralising for some therapies. We review the occurrence of adverse events, both the more common and troublesome effects and those that are less common but have potentially much more serious outcomes. Ways of mitigating these risks and managing the more troublesome adverse effects are also reviewed. Finally, we make specific recommendations with regards to the treatment of MS. It is an exciting time in the world of MS neurology and the prospects for further advances in coming years are high.

Axonal loss of retinal neurons in multiple sclerosis associated with optic radiation lesions

OBJECTIVE

To investigate the potential links between thinning of retinal ganglion cell axons in eyes of patients with multiple sclerosis (MS) without past optic neuritis (ON) and MS-related inflammatory damage of the posterior visual pathway.

METHODS

Temporal retinal nerve fiber layer (tRNFL) thickness was analyzed in eyes with no history of ON (NON) from 53 patients with relapsing-remitting MS. Fifty normal age- and sex-matched controls were examined with optical coherence tomography. Low-contrast visual acuity charts were used for functional assessment of vision. The optic tract (OT) and optic radiation (OR) were identified using probabilistic tractography, and volume of T2 fluid-attenuated inversion recovery lesions and diffusion tensor imaging (DTI) indices were measured within both structures. Cross-sectional diameter of the OT was also calculated.

RESULTS

tRNFL thickness was significantly reduced in NON eyes and was associated with reduced low-contrast visual acuity. Lesions within the OR were detected in the majority of patients. There was a significant correlation between thinning of the tRNFL and OR lesion volume (adjusted for non-OR lesion volume, age, sex, and disease duration). tRNFL thickness also correlated with OR DTI indices. No OT lesions were identified in any of the patients and no relationship between retinal nerve fiber layer loss and potential markers of OT lesions was found.

CONCLUSION

The results demonstrate a strong tract-specific association between loss of tRNFL fibers and MS-related inflammation within OR.

Latency of multifocal visual evoked potentials in nonoptic neuritis eyes of multiple sclerosis patients associated with optic radiation lesions

PURPOSE

The aim of the study was to test the hypothesis that latency delay of multifocal visual evoked potentials (mfVEP) in nonoptic neuritis (NON) eyes of multiple sclerosis (MS) patients is related to retrochiasmal demyelinating lesions.

METHODS

A total of 57 MS patients with no history of optic neuritis at least in one eye, and 25 age- and sex-matched healthy controls was enrolled. Probabilistic tractography was used to reconstruct optic radiation (OR) fibers. The MS lesion volume within and outside of OR was calculated. Diffusion tensor imaging (DTI) indices were measured along OR fibers. The relationship of the mfVEP latency with OR lesions and DTI indices was examined.

RESULTS

Average mfVEP latency in the MS cohort was significantly delayed compared to controls (P < 0.0001). Of the patients, 77% demonstrated OR lesions. Axial, radial, and mean diffusivity were significantly abnormal in MS patients (P < 0.001). Partial correlation demonstrated significant association between mfVEP latency delay and OR lesion load. There was also significant correlation between MfVEP latency and OR DTI. Subgroup analysis revealed significantly higher correlations in patients without a history of ON in either eye compared to the fellow eye of patients with previous ON.

CONCLUSIONS

The findings of this study support our hypothesis that latency delay of the mfVEP in eyes of MS patients without previous ON is related to retrogenicular demyelinating lesions. Additionally, this study demonstrated that a previous episode of ON in the fellow eye may be a significant confounding factor, masking the relationship between the latency and OR lesions.

Inner nuclear layer thickening is inversley proportional to retinal ganglion cell loss in optic neuritis

Aim

To examine the relationship between retinal ganglion cell loss and changes in the inner nuclear layer (INL) in optic neuritis (ON).

Methods

36 multiple sclerosis (MS) patients with a history of ON and 36 age and sex-matched controls underwent Optical Coherence Tomography. The paramacular retinal nerve fiber layer (RNFL), combined ganglion cell and inner plexiform layers (GCL/IPL) and inner nuclear layer (INL) thickness were measured at 36 points around the fovea. To remove inter-subject variability, the difference in thickness of each layer between the ON and fellow eye of each patient was calculated. A topographic analysis was conducted.

Results

The INL of the ON patients was thicker than the controls (42.9µm versus 39.6µm, p=0.002). ON patients also had a thinner RNFL (27.8µm versus 32.2µm, p<0.001) and GCL/IPL (69.3µm versus 98.1µm, p<0.001). Among the controls, there was no correlation between RNFL and GCL/IPL as well as RNFL and INL, but a positive correlation was seen between GCL/IPL and INL (r=0.65, p<0.001). In the ON group, there was a positive correlation between RNFL and GCL/IPL (r=0.80, p<0.001) but a negative correlation between RNFL and INL (r=-0.61, p<0.001) as well as GCL/IPL and INL (r=-0.44, p=0.007). The negative correlation between GCL/IPL and INL strengthened in the ON group when inter-subject variability was removed (r=-0.75, p<0.001). Microcysts within the INL were present in 5 ON patients, mainly in the superior and infero-nasal paramacular regions. While patients with microcysts lay at the far end of the correlation curve between GCL/IPL and INL (i.e. larger INL and smaller GCL/IPL compared to other patients), their exclusion did not affect the correlation (r= -0.76, p<0.001).

Conclusions

INL enlargement in MS-related ON is associated with the severity of GCL loss. This is a continuous relationship and patients with INL microcysts may represent the extreme end of the scale.

The thalamus and multiple sclerosis: modern views on pathologic, imaging, and clinical aspects

The paired thalamic nuclei are gray matter (GM) structures on both sides of the third ventricle that play major roles in cortical activation, relaying sensory information to the higher cortical centers that influence cognition. Multiple sclerosis (MS) is an immune-mediated disease of the human CNS that affects both the white matter (WM) and GM. A number of clinical observations as well as recent neuropathologic and neuroimaging studies have clearly demonstrated extensive involvement of the thalamus, basal ganglia, and neocortex in patients with MS. Modern MRI techniques permit visualization of GM lesions and measurement of atrophy. These contemporary methods have fundamentally altered our understanding of the pathophysiologic nature of MS. Evidence confirms the contention that GM injury can be detected in the earliest phases of MS, and that iron deposition and atrophy of deep gray nuclei are closely related to the magnitude of inflammation. Extensive involvement of GM, and particularly of the thalamus, is associated with a wide range of clinical manifestations including cognitive decline, motor deficits, fatigue, painful syndromes, and ocular motility disturbances in patients with MS. In this review, we characterize the neuropathologic, neuroimaging, and clinical features of thalamic involvement in MS. Further, we underscore the contention that neuropathologic and neuroimaging correlative investigations of thalamic derangements in MS may elucidate not heretofore considered pathobiological underpinnings germane to understanding the ontogeny, magnitude, and progression of the disease process.