Optic neuromyelitis syndrome in Brazilian patients

La neuromyélite optique rémittente: données neuroradiologiques

INTRODUCTION

Neuromyelitis optica (NMO) is a rare inflammatory and demyelinating disorder of the central nervous system, restricted to optical nerves and spinal cord. The main neuroradiological aspects, now summarized into a complete set of diagnosis criteria, are a normal cerebral MRI at onset and longitudinal involvement of the spinal cord concerning more than 3 vertebral segments. The clinical course and frequency of typical lesions remain unknown.

OBJECTIVE

We here report neuroradiological data from patients suffering from NMO.

METHODS

Brain and spinal cord MRI were systematically reviewed for 32 afro-Caribbean patients.

RESULTS

A typical longitudinal spinal lesion was seen in 44.7 percent with or without edema; a lesion involving less than 3 vertebral segments in 26.3 percent and no lesion in 21.1 percent. Longitudinal study of a few bouts suggested a progressive normalisation of spinal cord appearance. Atrophy was negatively correlated with immunosuppressive treatment. Cerebral lesions usually absent at onset were correlated to the follow-up. In a non-recursive condition, patients completed diagnostic criteria for encephalic and spinal lesions in 82.8 percent and 48.1 percent.

CONCLUSION

Radiology of spinal bouts showed multiple aspects besides the typical form. The notion of multiple bouts must be added to the spinal criteria to achieve good sensitivity. A typical extensive spinal lesion is usual in the follow-up, but seen after less then half of the bouts. Requiring such a lesion would delay the diagnosis.

La neuromyélite optique au Maroc

INTRODUCTION

Optic neuromyelitis or Devic's syndrome associates optic neuritis and myelitis. It can have a monophasic or relapsing course. The limits of this entity remain controversial.

METHODS

We analyzed the results of a retrospective series of Moroccan patients with Devic's syndrome defined on the basis of Wingerchuk's criteria.

RESULTS

Six women and three men were retained for study; average age was 39 years. Three patients presented with a monophasic form and six with relapsing disease. CSF analysis was abnormal in five. Brain MRI was normal in eight. Signal abnormalities extended over more than three vertebrae in eight patients. Infections were associated with neurological features in half of the patients.

DISCUSSION

Our results are in agreement with those of large series in the literature regarding the clinical, imaging, and laboratory findings and disease course. We also noted that infections were more frequently associated with Devic's syndrome in our patients.

CONCLUSION

Our study reports the results of the first North African series of Devic's syndrome patients. We suggest that this syndrome is particular in our context due to the high frequency and diversity of associated infections.

Neuromyelitis optica

The combination of optic neuritis and myelitis, the so-called Neuromyelitis optica is an uncommon pattern of demyelinating disorder. In 1870, Sir Thomas Clifford Allbutt first reported the association and Erb published a comparable report. Gowers and Dreschfeld described other instances in the 19th century. This paper attempts to review the syndrome to consider whether it merits recognition as a disease, sui generis, or rather as a syndrome symptomatic of multiple sclerosis, acute disseminated encephalomyelitis, and other immunological disorders. Two forms are distinguished: a monophasic illness, and a relapsing form. The claimed differential features separating it from classical multiple sclerosis are appraised. Modern immunology suggests an antibody-dependent, complement-mediated pathogenesis.

Neuromyélite optique de Devic et hépatite virale A

INTRODUCTION

Devic optic neuromyelitis is a rare clinical disease that involves severe transverse myelitis and unilateral or bilateral optic neuropathy. Its pathogenesis would be explained by demyelinization triggered by bacterial or viral infections phenomena. According to several author, prognosis would be better in children.

CASE REPORT

We report a case of optic neuromyelitis in an 8-year-old child with an uneventful history who was admitted because he suffered from flaccid tetraplegia and sudden decline of the visual acuity. The ophthalmologic examination revealed bilateral neuropapillitis. The medullary MRI visualized a spreading myelitis with bifocal arachnoiditis. Search for a precipitating infectious factor showed positive IgM for viral hepatitis A. With corticosteroid treatment the child achieved total recovery of vision and recovered motor and sensorial function of the upper limbs and the trunk. Paraplegia with sphincteral disorders persisted.

CONCLUSION

This case characterized by the precipitating factor (hepatitis virus A), illustrates this rare syndrome. We present a general review of the pediatric cases reported in the literature.

Genes, environment, and susceptibility to multiple sclerosis

Multiple sclerosis (MS) is a chronic disease of the central nervous system affecting young adults and thus representing a major burden also for their families and communities. The etiology of MS is obscure and its pathogenesis is yet incompletely depicted. Increased evidences indicate a strong genetic contribution to MS susceptibility, although others support the view that it is also influenced by environmental factors, possibly related to still unidentified pathogens. MS appears to be more heterogeneous than previously believed at the immunological level, and new pathological studies indicate a series of subset of conditions under the common denominator MS. The use of genetically homogeneous and geographically isolated populations at high MS risk, such as that of Sardinia, insular Italy, becomes in principle a vital requirement to reduce biological variables and the intrinsic complexity of the disease. This review will focus on recent findings on the peculiarity of Sardinian MS concerning epidemiological, genetic, and environmental aspects. Epidemiological studies reveal a clear heterogeneous distribution of MS cases in the Northern province of Sassari which may not be uniquely assigned to genetic variations. Furthermore, a different immunogenetic profile, including the association with other immunomediated diseases, and a progressive change in clinical phenotype, including age at onset, are present in this island which gives us unexpected variations at the level of patients' cohort and territorial distribution, especially when the northern province is compared to the southern one. This renders MS etiopathogenesis more complex than formerly thought even in this selected and genetically stable population.

The nature of multiple sclerosis

Multiple sclerosis (MS) has recently been classified according to its clinical course. Despite relapses and remissions, its course is invariably progressive, and the observed progression from the remitting-relapsing to the secondary progressive form represents the accumulation of permanent damage to the nervous system. Discussions of the nomenclatural position of Schilder's, Marburg's, and Baló's diseases, ignore the fact that the unique, pathognomonic, sharp-edged plaque of MS, is also the pathologic end-result in the three variants. Devic's disease or neuromyelitis optica (NMO) is quite different and with some exceptions, is a particular form of disseminated encephalomyelitis (DEM). There is no evidence that the 'oriental form of MS' is anything but NMO. The suggestion that MS and DEM are variants of the same condition is contradicted by the fact that the pathological characteristics of the two are quite different. While it is probable that the two share aspects of pathogenesis, the patients differ because of their genetic endowment. This was dramatically demonstrated in a group of Japanese patients who died after anti-rabies vaccination and were found to have the typical sharp-edged lesions of MS. The genetic determinant was also crucial in the marmoset in which EAE uniquely resulted in a chronic relapsing-remitting (RR) disease characterized by the classic sharp-edged lesions of MS. The question 'ADEM: distinct disease or part of the MS spectrum?' can be answered with a resounding no. A new classification is proposed separating the different forms of MS from the various types of DEM.