Disseminated encephalomyelitis and multiple sclerosis: two different diseases - a critical review.

The practice of initiating immunomodulatory treatment immediately after a clinically isolated syndrome (CIS) suggestive of multiple sclerosis (MS) emphasizes the need to distinguish between disseminated encephalomyelitis (DEM) and MS. Their clinical, genetic, imaging, and histopathological characteristics establish that they are distinct disease entities. Acute and recurrent DEM are more common in children, but also occur in adults. DEM is polysymptomatic and includes signs and symptoms rarely encountered in MS, such as fever, alterations of the state of consciousness, cognitive and aphasic symptoms, and meningism. Cerebrospinal oligoclonal bands are rare. Magnetic resonance imaging (MRI) is the best means of distinguishing between DEM and MS. In the former, the lesion load is heavy, thalamus or basal ganglia are often affected, and early in the disease most of the lesions are usually larger than those of MS and enhance with gadolinium. The MRI spinal cord lesions are longer than three vertebral segments, and define neuromyelitis optica (NMO). Antibodies against aquaporin-4 are present in some NMO, but are also found in cases of MS and DEM. Most NMO are forms of DEM, not MS, and are identical with the 'Oriental' or 'optico-spinal' form of MS.

Multiple sclerosis trait: the premorbid stage of multiple sclerosis. A hypothesis.

The unexpectedly low rate of concordance in monozygotic (MZ) twins with multiple sclerosis (MS) suggests that they share a systemic condition called the multiple sclerosis trait. This trait constitutes the premorbid stage of the disease and is quite distinct from asymptomatic MS. It results from the action of an antigenic challenge to the immune system of a genetically susceptible person but is short of producing lesions of the central nervous system parenchyma; in fact, the disease may never develop in people with the trait. An environmental triggering event is required to transform the trait into the disease. The discordance of clinical involvement and magnetic resonance images in MZ twins reflects differences in the effect of environmental influences.

Optic neuromyelitis syndrome in Brazilian patients.

OBJECTIVES: To report the clinical features and outcome of 24 Brazilian patients with optic neuromyelitis syndrome (ONM); discuss the underlying pathological events associated with the ONM syndrome; review the nosological situation of ONM in the group of inflammatory and demyelinating diseases of the central nervous system. PATIENTS AND METHODS: Patients with ONM treated at the Hospital da Lagoa, Rio de Janeiro were studied. Demographic, clinical, magnetic resonance imaging, cerebrospinal fluid, and pathological data were analysed. RESULTS: The study consisted of 20 women, four men of whom 10 were white and 14 Afro-Brazilians. Clinical course was recurrent in 22 cases and monophasic in two. Neurological manifestations at inclusion were: sensory impairment (66%), bilateral (41.6%) or unilateral blindness (20.8%), paraplegia or quadriplegia (37.5%). The EDSS was moderate/severe in 70.8%. The underlying pathological events were respectively pulmonary tuberculosis and upper respiratory infection in the two monophasic cases; in the 22 recurrent ONM patients: pulmonary tuberculosis (3), neurocysticercosis (1), polyarteritis nodosa (1), antinuclear antibody and rheumatoid factor (1), antiphospholipid antibody primary syndrome (1), diabetes mellitus (1), hypothyroidism (1), and amenorrhea-galactorrhea (4). Normal cerebrospinal fluid was found in 52% and an inflammatory profile in 48%. Only four recurrent ONM white patients had brain and spinal cord magnetic resonance imaging and cerebrospinal fluid findings compatible with the diagnosis of multiple sclerosis. Large lesions were seen in 62% of spinal magnetic resonance images. Six of 12 recurrent ONM Afro-Brazilian died. There were no statistical differences in the demographic data of the two ethnic groups. Afro-Brazilians were significantly more severely impaired and had a higher mortality rate than the white patients. CONCLUSION: These cases were classified as follows: two monophasic acute disseminated encephalomyelitis; one recurrent disseminated encephalomyelitis; three recurrent ONM associated with Hughes syndrome, autoantibodies and polyarteritis nodosa; six recurrent ONM with endocrinopathies; and finally, four multiple sclerosis cases. The remaining cases were not associated with any other condition. It would seem clear that ONM is a syndrome rather than a single disease.

A case of multiple sclerosis triggered by organic solvents.

The neurotoxicity of organic solvents has long been recognized. Some are used as anesthetic agents, others in various industries. Their acute effect has been well documented since the nineteenth century, but more recently they have become notorious as the cause of addiction to glue sniffing. They may alter the immune system by causing lymphopenia, impairing phagocytosis and decreasing the level of serum complement, as well as altering the impermeability of the blood-brain barrier and leading to the appearance of white matter lesions in the brain. The following case study explores the possible role of organic solvents in the pathogenesis of multiple sclerosis.

Diagnostic criteria for multiple sclerosis.

Over a hundred years ago, Charcot set down what he considered to be some of the clinical characteristics of multiple sclerosis (MS). His triad was not specific but it was the first attempt to separate this disease from the many others affecting the nervous system. The history of clinical diagnostic criteria demonstrates the evolution from rather tentative classifications of restricted value to the more elaborate 1983 scheme which incorporates some laboratory procedures under the rubric paraclinical tests, considered to be extensions of the neurological examination, as well as a new category based on the presence of specific abnormalities of the cerebrospinal fluid (CSF). It is curious that until then the term definite MS had been avoided except for autopsy-proven cases, perhaps a wise move, since exact diagnosis may require long term observation. All the proposed schemes have been based on the twin principles of dissemination in both time and space. The diagnosis of MS must remain a clinical one, supported but not supplanted by the increasingly popular magnetic resonance imaging, which is non-specific and is frequently overinterpreted by radiologists lacking appropriate clinical information. Reliance on the MRI as the principal if not exclusive basis for the diagnosis leads to error in as many as one third of cases. This assumes a great deal of importance considering that such non-MS patients may be counted in epidemiological surveys and included in therapeutic trials for disease-modifying drugs, or eventually treated with these very expensive drugs with still controversial long term efficacy. Not surprisingly, attempts to develop reliable criteria for the MRI diagnosis of MS have been unsuccessful in view of the lack of specificity of that procedure. Great care should be taken to exclude the presence of extrinsic cervical spine lesions which might impinge on the cord, leading to the formation of plaques, or mimic the course of MS. An MRI of the cervical spine is recommended in all patients suspected of having MS who have symptoms suggestive of spinal cord involvement. The diagnosis of MS is, and will remain, based on clinical criteria which codify the characteristic dissemination in time and space of MS.

The pathogenesis of multiple sclerosis: a commentary.

A series of recently published articles by a group of Austrian, German and American neuropathologists have proposed the existence of several different pathogenetic pathways in multiple sclerosis (MS). These studies were based on both biopsy and autopsy material. A review of the available published clinical, imaging and cerebrospinal fluid data suggest that some the cases used in those studies were more probably instances of disseminated encephalomyelitis rather than MS. This has serious implications regarding the specificity and significance of the findings in regard to MS pathogenesis. The specific myelinoclastic sequence and the variable clinical course of MS are determined by the individual's genetic endowment and immunologic history. Regardless of pathogenetic pathway and clinical course, the final pathologic picture of MS is always the same. The MS brain is genetically programmed to produce a unique, pathognomonic change, the plaque with sharply demarcated borders.

Recurrent optic neuromyelitis with endocrinopathies: a new syndrome.

We report a new syndrome that we call "recurrent optic neuromyelitis with endocrinopathies" in eight Antillean women from Martinique and Guadeloupe Ocular involvement was either monocular or binocular, whereas myelopathy was acute or subacute. In seven patients, myelopathic symptoms recurred, and in six patients, visual problems recurred. Spinal cord involvement was a consistent band-like pseudo-syringomyelic dissociated sensory loss. All eight patients had endocrinopathies consisting of amenorrhea, galactorrhea, diabetes insipidus, hypothyroidism, or hyperphagia. Spinal cord MRI revealed cavitation-like images. Various immunosuppressant treatments had little effect on the uniformly deteriorating course, ending in blindness and paraplegia. Six patients died within 5 years of onset, and an autopsy in one patient showed multiple demyelinizing lesions of the spinal cord with thickened blood vessels walls without evidence of inflammation. These cases appear to constitute a syndrome distinct from MS and from classic Devic's syndrome, not only because of the association with endocrinopathies but because of the stereotypy of the recurrences, the absence of MRI lesions in the cerebral white matter, and the unusual image of cavitation of the spinal cord. The syndrome is also distinct from HTLV-I-associated paraparesis, which is endemic in the West Indies.

Brain lesions in patients with multiple sclerosis: detection with echo-planar imaging.

PURPOSE: To evaluate the detection of brain lesions with echo-planar imaging relative to conventional spin-echo (SE) imaging. MATERIALS AND METHODS: In 17 patients (three men, 14 women; mean age, 31 years) with multiple sclerosis, the following were compared: single-shot proton-density- and T2-weighted and thin-section T2-weighted echo-planar, proton-density- and T2-weighted multishot echo-planar, and conventional SE sequences. Quantitative and qualitative criteria as well as lesion detectability were evaluated. The proton-density-weighted SE sequence was used as the standard of reference. RESULTS: Multishot sequences were superior to single-shot sequences in image quality and lesion detectability. With the multishot proton-density-weighted sequence, 53 of 54 large lesions and 23 of 30 small lesions were detected; with the single-shot proton-density-weighted sequence, 38 of 54 large lesions and five of 30 small lesions were detected. CONCLUSION: With multishot echo-planar sequences, detectability of large lesions is similar to that with conventional SE imaging. Susceptibility artifact is diminished in comparison to single-shot echo-planar sequences.