Clinical course, therapeutic responses and outcomes in relapsing MOG antibody-associated demyelination.

Abstract OBJECTIVE: We characterised the clinical course, treatment and outcomes in 59 patients with relapsing myelin oligodendrocyte glycoprotein (MOG) antibody-associated demyelination. METHODS: We evaluated clinical phenotypes, annualised relapse rates (ARR) prior and on immunotherapy and Expanded Disability Status Scale (EDSS), in 218 demyelinating episodes from 33 paediatric and 26 adult patients. RESULTS: The most common initial presentation in the cohort was optic neuritis (ON) in 54% (bilateral (BON) 32%, unilateral (UON) 22%), followed by acute disseminated encephalomyelitis (ADEM) (20%), which occurred exclusively in children. ON was the dominant phenotype (UON 35%, BON 19%) of all clinical episodes. 109/226 (48%) MRIs had no brain lesions. Patients were steroid responsive, but 70% of episodes treated with oral prednisone relapsed, particularly at doses <10\u2009mg daily or within 2 months of cessation. Immunotherapy, including maintenance prednisone (P=0.0004), intravenous immunoglobulin, rituximab and mycophenolate, all reduced median ARRs on-treatment. Treatment failure rates were lower in patients on maintenance steroids (5%) compared with non-steroidal maintenance immunotherapy (38%) (P=0.016). 58% of patients experienced residual disability (average follow-up 61 months, visual loss in 24%). Patients with ON were less likely to have sustained disability defined by a final EDSS of 652 (OR 0.15, P=0.032), while those who had any myelitis were more likely to have sustained residual deficits (OR 3.56, P=0.077). CONCLUSION: Relapsing MOG antibody-associated demyelination is strongly associated with ON across all age groups and ADEM in children. Patients are highly responsive to steroids, but vulnerable to relapse on steroid reduction and cessation

Relapse patterns in NMOSD: evidence for earlier occurrence of optic neuritis and possible seasonal variation

Neuromyelitis optica spectrum disorders (NMOSD) and multiple sclerosis (MS) show overlap in their clinical features. We performed an analysis of relapses with the aim of determining differences between the two conditions. Cases of NMOSD and age- and sex-matched MS controls were collected from across Australia and New Zealand. Demographic and clinical information, including relapse histories, were recorded using a standard questionnaire. There were 75 cases of NMOSD and 101 MS controls. There were 328 relapses in the NMOSD cases and 375 in MS controls. Spinal cord and optic neuritis attacks were the most common relapses in both NMOSD and MS. Optic neuritis (p P = 0.002) were more common in NMOSD and other brainstem attacks were more common in MS (p P = 0.065). Optic neuritis and transverse myelitis are the most common types of relapse in NMOSD and MS. Optic neuritis tends to occur more frequently in NMOSD prior to the age of 30, with transverse myelitis being more common thereafter. Relapses in NMOSD were more severe. A seasonal bias for relapses in spring-summer may exist in NMOSD

Imaging the anterior visual pathway in neurological disease

Axonal loss is an important cause of irreversible disability in multiple sclerosis. Whilst recovery of neurological function due to restoration of neuronal conduction is usual after multiple sclerosis relapse, some relapses are followed by fixed disability. Quantitative measures of axons in the retina, and in their continuation in the optic nerve allow measurement of the effect upon axons of a prototypical multiple sclerosis relapse, optic neuritis. Using optical coherence tomography, axonal and neuronal loss were observable in the retina of patients with progressive multiple sclerosis, even when they were clinically unaf- fected by optic neuritis. With follow-up, these changes were found to be stable. After optic neuritis, 99% of retinal nerve fibre layer thinning was detectable by 4.75 months, and 99% of macular volume loss was detectable by 11 months. The earliest time to detect retinal nerve fibre layer thinning was 1.64 months, and the earliest time to detect macular volume loss was 0.99 months. Sample sizes for clinical trials generated for trials of neuro-protective agents, using multiple sclerosis thickness as an endpoint, showed that 35 subjects per arm of a randomised trial would be needed to detect an 50% effect, with 80% power. Early measures of colour vision and visual evoked potential delay were strongly related to the eventual degree of axonal loss. Comparisons of two methods of measuring multiple sclerosis thinning after optic neuritis suggested that optical coherence tomography would be superior to scanning laser polarimetry. Comparisons of optic nerve mean area and multiple sclerosis thickness showed that whilst initial swelling was similar, the degree of subsequent atrophy was less in the optic nerve. Measures of axonal loss in the retina will be an important method for assessing the efficacy of therapies that propose to prevent axonal loss in multiple sclerosis and optic neuritis

An investigation of the retinal nerve fibre layer in progressive multiple sclerosis

Axonal loss is thought to be the predominant cause of disability in progressive multiple sclerosis (MS). The retinal nerve fibre layer (RNFL) is composed largely of unmyelinated axons of retinal ganglion cells, and is accessible to study with optical coherence tomography (OCT), giving a measure of axonal loss. OCT measures of the RNFL thickness (RNFLT) and macular volume were studied in 23 patients with primary progressive multiple sclerosis (primary progressive MS) (13 male; 10 female; mean age 52 years; median EDSS 6.0; mean disease duration 11 years), and 27 patients with secondary progressive multiple sclerosis (secondary progressive MS) (8 male; 19 female; mean age 50 years; median EDSS 6; mean disease duration 22 years). Of the patients with secondary progressive MS, 14 had clinical history of optic neuritis (ON) in a single eye; the remaining patients had not had ON. Twenty healthy controls (11 male; 9 female; mean age 46 years) had RNFLT and macular volume studied. Of the patients eyes not previously affected by ON, both the mean RNFL thickness and macular volume were reduced when compared with control values. The mean RNFL thickness and macular volume were significantly reduced in secondary progressive MS, but not in primary progressive MS when compared with control RNFL thickness and macular volume. RNFL loss was most evident in the temporal quadrant, where significant reduction was seen in primary progressive MS versus controls and in secondary versus primary progressive MS. There were significant correlations of decreased RNFLT and macular volume with measures of visual acuity, low contrast visual acuity and visual field mean deviation in the MS patients. There are significant global reductions in RNFLT and macular volume in the eyes of secondary progressive MS patients not previously affected by ON, but not in primary progressive MS patients, compared with controls. This may indicate a difference in the extent of the pathological processes that cause axonal loss in the retina, and by inference the optic nerve, in secondary progressive MS and primary progressive MS