Risk of multiple sclerosis after optic neuritis in patients with normal baseline brain MRI

Comparison between contrast-enhanced fat-suppressed 3D FLAIR brain MR images and T2-weighted orbital MR images at 3 Tesla for the diagnosis of acute optic neuritis

PURPOSE

The purpose of this study was to compare the capabilities of contrast-enhanced fat-suppressed (CE FS) three-dimensional fluid-attenuated inversion recovery (3D FLAIR) brain magnetic resonance imaging (MRI) with those of coronal T2-weighted orbital MRI obtained at 3 Tesla for the diagnosis of optic neuritis (ON).

MATERIALS AND METHODS

Patients who presented to our center with acute visual loss and underwent MRI examination of the orbits and the brain between November 2014 and February 2020 were retrospectively included. Three radiologists independently and blindly analyzed CE FS 3D FLAIR and coronal T2-weighted images. Disagreements in image interpretation were resolved by consensus with an independent neuroradiologist who was not involved in the initial reading sessions. The primary adjudication criterion for the diagnosis of ON was the presence of an optic nerve hypersignal. Sensitivity, specificity, and accuracy of CE 3D FLAIR brain images were compared with those of coronal T2-weighted orbital images using McNemar test. Artifacts were classified into three categories and compared between the two image sets.

RESULTS

A total of 1023 patients were included. There were 638 women and 385 men with a mean age of 42 ± 18.3 (standard deviation) years (age range: 6-92 years). Optic nerve hyperintensities were identified in 375/400 (94%) patients with ON using both 3D FLAIR and coronal T2-weighted images. Sensitivity, specificity, and accuracy of both sequences were 94% (95% CI: 91.3-96.1), 79% (95% CI: 75.5-82.2), and 89% (95% CI: 86.8-90.7), respectively. Optic disc hypersignal was detected in 120/400 patients (30%) using 3D FLAIR compared to 3/400 (0.75%) using coronal T2-weighted images (P < 0.001). Optic radiation hypersignal was observed in 2/400 (0.5%) patients using 3D FLAIR images. Significantly more artifacts (moderate or severe) were observed on coronal T2-weighted images (801/1023; 78%) by comparison with 3D FLAIR images (448/1023; 44%) (P < 0.001).

CONCLUSION

The performance of 3D FLAIR brain MRI for the diagnosis of ON is not different from that of coronal T2-weighted orbital MRI and its use for optic nerve analysis may be beneficial.

Comparison of a Whole-Brain Contrast-Enhanced 3D TSE T1WI versus Orbits Contrast-Enhanced 2D Coronal T1WI at 3T MRI for the Detection of Optic Nerve Enhancement in Patients with Acute Loss of Visual Acuity

BACKGROUND AND PURPOSE

MR imaging is the technique of choice for patients presenting with acute loss of visual acuity with no obvious ophthalmologic cause. The goal of our study was to compare orbits contrast-enhanced 2D coronal T1WI with a whole-brain contrast-enhanced 3D (WBCE-3D) TSE T1WI at 3T for the detection of optic nerve enhancement.

MATERIALS AND METHODS

This institutional review board-approved retrospective single-center study included patients presenting with acute loss of vision who underwent 3T MR imaging from November 2014 to February 2020. Two radiologists, blinded to all data, individually assessed the presence of enhancement of the optic nerve on orbits contrast-enhanced 2D T1WI and WBCE-3D T1WI separately and in random order. A McNemar test and a Cohen κ method were used for comparing the 2 MR imaging sequences.

RESULTS

One thousand twenty-three patients (638 women and 385 men; mean age, 42 [SD, 18.3] years) were included. There was a strong concordance between WBCE-3D T1WI and orbits contrast-enhanced 2D T1WI when detecting enhancement of the optic nerve: κ = 0.87 (95% CI, 0.84-0.90). WBCE-3D T1WI was significantly more likely to detect canalicular enhancement compared with orbits contrast-enhanced 2D T1WI: 178/1023 (17.4%) versus 138/1023 (13.5%) (P < .001) and 108/1023 (10.6%) versus 90/1023 (8.8%) (P = .04), respectively. The WBCE-3D T1WI sequence detected 27/1023 (3%) instances of optic disc enhancement versus 0/1023 (0%) on orbits contrast-enhanced 2D T1WI. There were significantly fewer severe artifacts on WBCE-3D T1WI compared with orbits contrast-enhanced 2D T1WI: 68/1023 (6.6%) versus 101/1023 (9.8%) (P < .001). The median reader-reported confidence was significantly higher with coronal T1WI compared with 3D TSE T1WI: 5 (95% CI, 4-5) versus 3 (95% CI, 1-4; P < .001).

CONCLUSIONS

Our study showed that there was a strong concordance between WBCE-3D T1WI and orbits contrast-enhanced 2D T1WI when detecting enhancement of the optic nerve in patients with acute loss of visual acuity with no obvious ophthalmologic cause. WBCE-3D T1WI demonstrated higher sensitivity and specificity in diagnosing optic neuritis, particularly in cases involving the canalicular segments.

Development of a Prognostic Model for Predicting Multiple Sclerosis After Optic Neuritis: A Secondary Analysis of Data From the Optic Neuritis Treatment Trial

BACKGROUND

Optic neuritis can be the initial manifestation of multiple sclerosis (MS). The purpose of this study was to develop a prognostic model for predicting the risk of MS development among patients with optic neuritis.

METHODS

The data from 388 patients with optic neuritis were retrieved from the Optic Neuritis Treatment Trial (ONTT). Cox proportional hazards regression analysis was used to develop a prognostic model. The performance of the model was assessed by using Harrell's C-index and calibration curves. The rates of MS development were estimated using the Kaplan-Meier method.

RESULTS

Among the enrolled subjects, a total of 154 (39.7%) patients developed clinically definite MS during a median follow-up period of 15.8 years (interquartile range, 7.2-16.9 years). The factors associated with the development of MS were the presence of brain lesions as on baseline MRI, previous nonspecific neurologic symptoms, commencing low-dose corticosteroids treatment, ocular pain, and absence of optic disc/peripapillary hemorrhage. After incorporating these 5 factors into the prognostic model, a C-index of 0.72 (95% confidence interval [CI], 0.69-0.76) and good calibration curves were obtained. The C-index of the model was significantly higher than the C-indexes of any single factor (P < 0.001 in all cases). The model was able to stratify the ONTT patient cohort into 3 risk groups with significantly different intergroup rates of developing MS (rates for developing MS within a 15-year period: high-risk group, 75.7% [95% CI, 65.6%-82.9%], intermediate-risk group, 44.7% [95% CI, 31.4%-55.4%]; and low-risk group, 20.8% [95% CI, 14.2%-26.8%]; log-rank P < 0.001).

CONCLUSIONS

This prognostic model had a better prediction ability when compared with the standard practice that relies solely on using brain lesions on MRI. It can, therefore, help guide decision-making to initiate earlier disease-modifying therapy for patients with optic neuritis at risk of developing MS.

A prospective, observational study on conversion of clinically isolated syndrome to multiple sclerosis during 4-year period (MS NEO study) in Taiwan

Importance

CIS to MS conversion rates vary depending on population cohorts, initial manifestations, and durations of follow-up.

Objective

To investigate conversion rate of patients from CIS to MS and the prognostic significance of demographic and clinical variables in Taiwanese population.

Design

Nationwide, prospective, multi-centric, observational study from November 2008 to November 2014 with 4 years follow-up.

Setting

Multi-centre setting at 5 institutions in Taiwan.

Participants

152 patients having single clinical event potentially suggestive of MS in last 2 years were enrolled as consecutive sample. 33 patients were lost to follow-up and 16 patients did not complete the study.103 patients completed the study.

Intervention(s) (for clinical trials) or exposure(s) (for observational studies)

Natural progression from first episode of CIS to MS or NMO was observed.

Main outcome(s) and measure(s)

Variables analysed were ‘proportion of patients converting to MS or NMO after first episode of CIS’, ‘duration between first episode of neurological event and diagnosis of MS’, ‘status of anti-AQP4 IgG’ and ‘length of longest contiguous spinal cord lesion in MS patients’. Association between baseline characteristics and progression to MS from CIS was analyzed using multiple logistic regression. Multivariate time dependent effect of baseline characteristics on progression to MS was plotted.

Results

14.5% patients with CIS converted to MS after 1.1 ± 1.0 years with greater predisposition (18.8%) in those having syndromes referable to the cerebral hemispheres. Conversion rate from ON to MS was 9.7%. 90.9% patients had mild disease course. 46.7% patients had abnormal MRIs at baseline, with 0.6±0.5 contrast enhanced lesions. ‘Below normal BMI’ and ‘MRI lesion load (≥ 4 lesions)’ were identified as risk indicators for the development of MS. Amongst the patients who developed NMO as diagnosed by modern criteria, 80% were positive for anti-AQP4 IgG antibody.

Conclusions and relevance

‘Below normal BMI’ and ‘number of demyelinating lesions (≥4)’ are significant predictors of conversion from CIS to MS. A low conversion rate to MS in Taiwanese CIS patients and majority of them having a mild course and minimal disability suggest the roles of geographic, genetic and ethnic factors.

Trial registration

Non-trial observational study.

Diagnostic imaging in neuro-ophthalmology

Neuro-ophthalmology is a field combining neurology and ophthalmology that studies diseases that affect the visual system and the mechanisms that control eye movement and pupil function. Imaging tests make it possible to thoroughly assess the relevant anatomy and disease of the structures that make up the visual pathway, the nerves that control eye and pupil movement, and the orbital structures themselves. This article is divided into three sections (review of the anatomy, appropriate imaging techniques, and evaluation of disease according to clinical symptoms), with the aim of providing useful tools that will enable radiologists to choose the best imaging technique for the differential diagnosis of patients' problems to reach the correct diagnosis of their disease.

Prevalence and Incidence of Optic Neuritis in Patients with Different Types of Uveitis

PURPOSE

This database study aims to investigate the incidence and prevalence of optic neuritis (ON) among patients with different types of uveitis.

METHODS

A retrospective analysis of the Truven Health MarketScan® database from 2000 to 2014 was conducted. Patients with uveitis were followed until diagnosis of ON or until they were censored. Diagnosis of uveitis and demyelinating diseases of the central nervous system (DD) including ON were based on ICD-9 codes. Patients with a diagnosis of DD at or before the index date of diagnosis of uveitis were excluded from incidence calculation. In the prevalence analysis, any diagnoses of DD during continuous enrollment were counted.

RESULTS

Among the 103,867 uveitis patients, 974 had ever been diagnosed with ON and 2121 with DD including ON during the continuous enrollment. Prevalence rates of ON in patients with intermediate, posterior and pan uveitis are approximately 2.0-2.5% while a lower prevalence (0.6%) of ON was observed in anterior uveitis. During a median follow-up period of 2.2 years, 463 new cases of ON were diagnosed. The incidence rates of ON per 100 person-years (95% CI) were 0.12 (0.11-0.13), 0.28 (0.18-0.41), 0.29 (0.23-0.35) and 0.38 (0.24-0.56), respectively, for anterior, intermediate, posterior and pan uveitis.

CONCLUSION

Incidence and prevalence of ON among patients with intermediate, posterior and pan uveitis were comparable and higher than the rates in patients with anterior uveitis.

The Diagnosis and Treatment of Optic Neuritis

BACKGROUND

Typical optic neuritis is often the presenting manifestation of multiple sclerosis (MS). Its incidence in central Europe is 5 cases per 100 000 persons per year.

METHODS

This review is based on articles retrieved by a selective search of the PubMed database, on the pertinent guidelines, and on the authors' clinical experience.

RESULTS

The diagnosis of optic neuritis is based on a constellation of symptoms and signs. The onset is usually with pain on eye movement in one eye and subacute visual loss. In unilateral optic neuritis, the direct pupillary light reflex is weaker in the affected eye. One-third of patients with optic neuritis have a mildly edematous optic disc. The visual disturbance resolves in 95% of cases. A less favorable course may be evidence of neuromyelitis optica, and macular involvement may be evidence of neuroretinitis. High-dosed intravenous methylprednisolone therapy speeds recovery but does not improve the final outcome. The risk that a patient with optic neuritis will later develop multiple sclerosis can be assessed with an MRI scan of the brain.

CONCLUSION

Optic neuritis is easy to distinguish from otherv diseases affecting the optic nerve. Atypical forms of this disease and other optic nerve diseases require special treatment. For patients judged to be at high risk of developing multiple sclerosis, immune prophylaxis with beta- interferon or glatiramer acetate is recommended.

Serum sPECAM-1 and sVCAM-1 levels are associated with conversion to multiple sclerosis in patients with optic neuritis

Platelet-Endothelial-Cell-Adhesion-Molecule-1 (PECAM-1) and Human-Vascular-CAM-1 (VCAM-1) are adhesion molecules involved in leukocyte-endothelial interaction. In our study serum levels of sPECAM-1 and sVCAM-1 were measured (ELISA) in twenty-nine patients during their first monosymptomatic optic neuritis (ON) episode. Anti-aquaporin-4-antibodies (AQP4-IgG) were detected with the cell-based assay. Patients were followed for seven years, during which 16/24 AQP4-IgG (-) patients developed MS and 2/5 AQP4-IgG (+) patients developed NMO. Patients who developed MS had significantly lower sPECAM-1 and sVCAM-1 than those who did not. Serum sPECAM-1 and sVCAM-1 may turn out to be useful biomarkers correlated with the risk of progression to MS after first ON incident.

MRI in the Evaluation of Acute Visual Syndromes

Acute visual symptom emergencies occur commonly and present a challenge to both clinical and radiologic facets. Although most patients with visual complaints routinely require clinical evaluation with direct ophthalmologic evaluation, imaging is rarely necessary. However, there are highly morbid conditions where the prompt recognition and management of an acute visual syndrome (AVS) requires an astute physician to probe further. Suspicious symptomatology including abrupt visual loss, diplopia, ophthalmoplegia, and proptosis/exophthalmos require further investigation with advanced imaging modalities such as magnetic resonance imaging and magnetic resonance angiography. This review will discuss a variety of AVSs including orbital apex syndrome, cavernous sinus thrombosis, cavernous carotid fistula, acute hypertensive encephalopathy (posterior reversible encephalopathy syndrome), optic neuritis, pituitary apoplexy including hemorrhage into an existing adenoma, and idiopathic intracranial hypertension. A discussion of each entity will focus on the clinical presentation, management and prognosis when necessary and finally, neuroimaging with emphasis on magnetic resonance imaging. The primary purpose of this review is to provide an organized approach to the differential diagnosis and typical imaging patterns for AVSs. We have provided a template for radiologists and specialists to assist in early intervention in order to decrease morbidity and provide value-based patient care through imaging.

Neuro-Ophthalmology Annual Review

PURPOSE

The purpose of this review was to update the practicing ophthalmologist on the English language neuro-ophthalmology literature from the past year.

DESIGN

A review of English language literature from August 1, 2013, to August 1, 2014, was conducted.

METHODS

The author searched PubMed from August 1, 2013, to August 1, 2014, limited to English language publications including original articles, review articles, and case reports and excluding letters to the editor, unpublished work, and abstracts. The following topics were searched: pupillary abnormalities, eye movement dysfunction, neuromuscular diseases, optic neuropathies, optic neuritis, demyelinating diseases including multiple sclerosis, lesions of the optic chiasm and posterior primary visual pathways, elevated intracranial pressure, tumors and aneurysms affecting the visual pathways, vascular diseases, higher visual function, and neuroimaging advances. The focus of this review is on clinically relevant literature in the past year for the practicing ophthalmologist. The aim was to highlight remarkable and interesting literature rather than exhaustively including all new neuro-ophthalmological publications of the year.

RESULTS

Initially, more than 11,000 articles were identified. One hundred were selected that met criteria specified above.

CONCLUSIONS

This review updates the comprehensive ophthalmologist on neuro-ophthalmic topics.

25-Hydroxyvitamin D levels in acute monosymptomatic optic neuritis: relation to clinical severity, paraclinical findings and risk of multiple sclerosis

Optic neuritis (ON) is a common first symptom of MS and only few studies have thus far investigated vitamin D at this early stage of MS. The objectives of the study were to examine total 25-hydroxyvitamin D levels (25HVITDL) in patients in acute (A) ON and to determine whether 25HVITD levels in AON (1) predict risk of RRMS and (2) are associated with visual tests of ON severity. A cross-sectional study was conducted of mean 25HVITDL differences between ON (n = 164) and MS (n = 948) patients and of prevalence of 25HVITDL deficiency (<50 nmol/L) in ON and MS (two-sample t test, χ (2) test). Associations between 25HVITDL and (1) clinical ON severity, (2) paraclinical findings suggestive of MS [logistic regression (LRA), Spearman correlation] and (3) hazard of MS development [Cox (C) RA] in ON patients were assessed. 25HVITDL were deseasonalized before analysis. The mean levels were 47.6 (ON) and 63.9 (MS) nmol/L (p < 0.0001), and a significantly higher prevalence of 25HVITD deficiency in ON (56 %; 35 %) (p < 0.0001), most pronounced in females, was shown. Associations were found between 25HVITDL and both CSF leukocyte count (ρ = -0.177, p = 0.028) and IgG index elevation (OR 0.980, p = 0.031). Forty-one ON patients developed MS during the study. Multivariate CRA showed no effect on hazard of MS (HR: 0.991, p 0.284). No association was found between 25HVITDL and visual tests (acuity, contrast vision) or OCT RNFL or GCL thickness. The study indicates a high prevalence of 25HVITD deficiency in AON. 25HVITDL was significantly associated with CSF leukocyte count, but not ON severity. The study indicates a possible role of vitamin D in the early stages of MS, but does not support the use of 25HVITDL as a predictor of MS development in acute ON.

Axonal degeneration in multiple sclerosis: can we predict and prevent permanent disability?

Axonal degeneration is a major determinant of permanent neurological impairment during multiple sclerosis (MS). Due to the variable course of clinical disease and the heterogeneity of MS lesions, the mechanisms governing axonal degeneration may differ between disease stages. While the etiology of MS remains elusive, there now exist potential prognostic biomarkers that can predict the conversion to clinically definite MS. Specialized imaging techniques identifying axonal injury and drop-out are becoming established in clinical practice as a predictive measure of MS progression, such as optical coherence tomography (OCT) or diffusion tensor imaging (DTI). However, these imaging techniques are still being debated as predictive biomarkers since controversy surrounds their lesion-specific association with expanded disability status scale (EDSS). A more promising diagnostic measure of axonal degeneration has been argued for the detection of reduced N-acetyl aspartate (NAA) and Creatine ratios via magnetic resonance spectroscopic (MRS) imaging, but again fail with its specificity for predicting actual axonal degeneration. Greater accuracy of predictive biomarkers is therefore warranted and may include CSF neurofilament light chain (NF-L) and neurofilament heavy chain (NF-H) levels, for progressive MS. Furthermore, defining the molecular mechanisms that occur during the neurodegenerative changes in the various subgroups of MS may in fact prove vital for the future development of efficacious neuroprotective therapies. The clinical translation of a combined Na⁺ and Ca²⁺ channel blocker may lead to the establishment of a bona fide neuroprotective agent for the treatment of progressive MS. However, more specific therapeutic targets to limit axonal damage in MS need investigation and may include such integral axonal proteins such as the collapsin response mediator protein-2 (CRMP-2), a molecule which upon post-translational modification may propagate axonal degeneration in MS. In this review, we discuss the current clinical determinants of axonal damage in MS and consider the cellular and molecular mechanisms that may initiate these neurodegenerative changes. In particular we highlight the therapeutic candidates that may formulate novel therapeutic strategies to limit axonal degeneration and EDSS during progressive MS.