Síndrome de Guillain-Barré ¿enfrentando un nuevo brote? Reporte de 4 casos / Guillain-Barre Syndrome. Report of 4 cases. Is this a new cluster?

El Síndrome de Guillain Barré (SGB) es una enfermedad inflamatoria desmielinizante aguda de probable etiología autoinmune, relacionada con diversos procesos infecciosos. Se caracteriza por debilidad muscular y disminución de los reflejos, pudiendo presentar un patrón clásico simétrico ascendente o con variables. La gravedad y pronóstico son variables, pudiendo comprometer los músculos torácicos derivando en insuficiencia respiratoria. Han sido descritos brotes endémicos asociados a diversos agentes infecciosos. Se presenta el reporte de 4 casos con el patrón más frecuente de SGB en los cuales se hizo el diagnóstico clínico confirmado por estudio del líquido cefalorraquídeo o electromiografía con progresión agresiva, 3 de ellos ameritando el traslado a unidad de terapia intensiva (UTI) para su tratamiento. Presentaron distintos factores de riesgo infecciosos como la suspensión de terapia antiretroviral y síntomas gastrointestinales, principalmente diarrea acuosa previo al debut de la paresia. Se implementó el tratamiento haciendo uso de plasmaféresis en uno de los casos e inmunoglobulina endovenosa en el resto con resultados variables. Se resalta la importancia del diagnóstico oportuno de esta patología ante la presencia de paresia y arreflexia con o sin patrón característico con la finalidad de atender la progresión de los mismos de forma adecuada, mejorar el pronóstico y evitar o disminuir las secuelas de los pacientes(AU)

Guillain Barré Syndrome (GBS) is an acute demyelinating inflammatory disease with probable autoimmune etiology related to diverse infectious processes. It is characterized by muscle weakness and diminished reflexes and may present an ascending symmetrical pattern or with other variables. The severity and prognosis are variable, and the thoracic muscles can be affected, resulting in respiratory failure. Endemic outbreaks associated with various infectious agents have been described. A report of 4 cases is presented in which the clinical diagnosis was confirmed by cerebrospinal fluid study or electromyography, with aggressive progression, 3 of them requiring to be transferred to the intensive care unit. The patients presented different infectious risk factors such as the interruption of anti-retroviral therapy and gastrointestinal symptoms, mainly watery diarrhea prior to the onset of the symptoms. The treatment was implemented using plasmapheresis in one of the cases and intravenous immunoglobulin in the rest with variable results. The importance of the timely diagnosis of this pathology in the presence of paresis and dimished reflexes with or without the characteristic pattern is highlighted in order to address the progression, appropriate management, improve the prognosis and avoid or reduce the sequelae of patients(AU)

Frequency of demyelinating pattern on electrophysiological study in patients with diabetic peripheral polyneuropathy

To determine the frequency of demyelinating pattern on electrophysiological study in patients with diabetic peripheral polyneuropathy. Cross sectional study. This study was performed at Department of Neurology, Mayo Hospital, Lahore and Medical Unit II, Allied Hospital, Faisalabad from 01-Jan-2012 to 30-Sep-2012. In this study non-probability purposive sampling technique was used. The calculated sample size was 100 cases. All patients with diabetic peripheral neuropathy and of both gender and age between 15-65 y were included in the study. Whereas Diabetic patients in whom history, clinical examination or medical record showing renal failure, hereditary neuropathies, thyroid disease, alcohol intake and toxic drug intake like anti tuberculous treatment, anti-cancer medicine etc were excluded from the study. Nerve conduction studies and electromyography were performed. Patients were labeled as having demyelinating, axonal or mixed pattern. The collected information was entered into SPSS version 15. Among the enrolled 100 patients, 56 [56%] patients were male and 44 [44%] patients were female. On electrophysiological examination, demyelinating pattern was found in 18[18%] patients, axonal pattern in 54[54%] patients and mixed pattern in 28[28%] patients. Mean duration of diabetes mellitus was 82 months + 56 S.D. The duration of diabetes ranged from 8-264 months. Our study indicates that there is high frequency of demyelinating neuropathy in patients of diabetic peripheral polyneuropathy in our local population

Ethidium bromide-induced demyelination in the sciatic nerve of diabetic rats / Desmielinização induzida pelo brometo de etídio no nervo ciático de ratos diabéticos

This study aims to observe the process of myelin loss and repair following the injection of the gliotoxic agent ethidium bromide (EB) in the sciatic nerve of rats previously induced to diabetes mellitus by streptozotocin. Injection of EB was also done in non-diabetic rats. The animals were euthanatized from 3 to 31 days after intraneural injection and nerve sections were collected for ultrastructural study. In non-diabetic rats, Schwann cells (CS) showed signs of intoxication 3 days after, with cytoplasmic vacuolization and rejection of their myelin sheaths. Myelin debris were removed by macrophages in the endoneurium and mast cells were abundant in the lesions. From 14 days following EB injection, supernumerary CS were seen in the expanded endoneurium as well as thin myelin sheaths indicating remyelination. Diabetic rats presented a more extensive myelin vesiculation and segmentar demyelination, with delayed activities from both macrophages and remyelinating SC. No mast cells were noted.

O estudo visa à observação do processo de perda e reparo mielínico pós-injeção do gliotóxico brometo de etídio (BE) no nervo ciático de ratos previamente induzidos a diabetes mellitus pela estreptozotocina. Injeção de BE foi igualmente realizada em ratos não-diabéticos. Os animais foram eutanasiados dos 3 aos 31 dias pós-injeção intraneural, com colheita de amostras neurais para estudo ultra-estrutural. Nos animais não-diabéticos, as células de Schwann (CS) mostraram sinais de intoxicação a partir dos 3 dias pós-gliotóxico, com vacuolização citoplasmática e rejeição de suas bainhas de mielina. Restos mielínicos eram removidos por macrófagos no interior do endoneuro e mastócitos eram abundantes nas lesões. A partir dos 14 dias, CS supranumerárias foram encontradas no endoneuro expandido, além de finas bainhas de mielina indicativas de remielinização. Os ratos diabéticos apresentaram vesiculação mielínica e desmielinização segmentar mais extensas, bem como ausência de mastócitos e atraso na atividade macrofágica e na função remielinizante das CS.

Remyelination in experimentally demyelinated connexin 32 KnockOut mice / Remielinização em camundongos KnockOut para conexina 32 desmielinizados experimentalmente

The aim of this study was to evaluate the role of connexin 32 (Cx 32) during remyelination of the peripheral nervous system, through a local injection of either 0,1 percent ethidium bromide solution or saline in the sciatic nerve of Cx 32 knockout mice. Euthanasia was performed ranging from 1, 2, 3, 7, 15, 21 to 30 days after injection. Histochemical, immunohistochemical, immunofluorescence and transmission electron microscopical techniques were used to analyze the development of the lesions. Within the sciatic nerves, Schwann cells initially showed signs of intoxication and rejected their sheaths; after seven days, some thin newly formed myelin sheaths with uneven compactness and redundant loops (tomacula) were conspicuous. We concluded that the regeneration of lost myelin sheaths within the PNS followed the pattern already reported for this model in other laboratory species. Therefore, these results suggest that absence of Cx 32 did not interfere with the normal pattern of remyelination in this model in young mice.

Este estudo visou avaliar o papel da conexina 32 (Cx 32) durante a remielinização no sistema nervoso periférico. Uma injeção local de 0,1 por cento de solução de brometo de etídio foi realizada no nervo ciático de camundongos deletados para a Cx 32, com eutanásia dos animais aos 1, 2, 3, 7, 15, 21 e 30 dias pós-injeção. Avaliações histoquímicas, imunoistoquímicas, por imunofluorescência e por microscopia eletrônica de transmissão foram utilizadas na análise do desenvolvimento das lesões. Nos nervos ciáticos, células de Schwann mostraram inicialmente sinais de intoxicação e rejeitaram suas bainhas. Após sete dias, observaram-se finas bainhas neoformadas, com compactação desigual e alças redundantes (tomácula). Conclui-se que a regeneração de bainhas de mielina perdidas no SNP seguiu o padrão já relatado deste modelo em outras espécies de laboratório. Portanto, estes resultados sugerem que a ausência da Cx 32 não interferiu com o padrão normal de remielinização em camundongos jovens neste modelo.

Ultrastructural study of the effects of cyclosporine in the brainstem of Wistar rats submitted to the ethidium bromide demyelinating model / Estudo ultra-estrutural dos efeitos da ciclosporina no tronco encefálico de ratos Wistar submetidos ao modelo desmielinizante do brometo de etídio

The ethidium bromide-demyelinating model (EB) was used to study remyelination in the brainstem under the use of cyclosporine (CsA). Wistar rats were submitted to intracisternal injection of 0.1 percent EB or 0.9 percent saline solution, and others were taken as histologic controls (group I). Within those injected with EB, some have not received immunosuppressive treatment (II); some were treated by intraperitonial route with CsA (III.E - 10 mg/kg/day). Rats from group III.C were injected with saline solution and treated with CsA. The animals were perfused from 15 to 31 days post-injection collecting brainstem sections for light and transmission electron microscopy studies. After EB injection it was noted the presence of macrophages and non-degraded myelin debris, demyelinated axons, oligodendrocyte or Schwann cell remyelinated axons, groups of infiltrating pial cells, hypertrophic astrocytes and few lymphocytes. Tissue repair of EB-induced lesions in group III.E was similar to that of group II, but with the presence of a higher density of oligodendrocytes near remyelinating areas.

Empregou-se o modelo desmielinizante do brometo de etídio (BE) com o objetivo de estudar a remielinização no tronco encefálico frente ao uso de ciclosporina (CsA). Foram utilizados ratos Wistar, submetidos à injeção de BE a 0,1 por cento ou de solução salina na cisterna pontina, assim como controles histológicos (grupo I). Dos animais injetados com BE, alguns não receberam tratamento imunossupressor (II); outros foram tratados por via intraperitoneal com CsA (III.E - 10 mg/kg/dia). O grupo III.C incluiu animais injetados com salina e tratados com CsA. Os animais foram perfundidos dos 15 aos 31 dias pós-injeção, com colheita de material do tronco encefálico para estudos de microscopia de luz e eletrônica de transmissão. Após injeção de BE, foram observados macrófagos e restos de mielina não-degradada, axônios desmielinizados ou remielinizados por oligodendrócitos e por células de Schwann, grupos de células piais infiltrantes, astrócitos hipertróficos e poucos linfócitos. O processo de reparo das lesões no grupo III.E apresentou-se similar ao do grupo II, porém com maior densidade de oligodendrócitos próximos às áreas de remielinização.

Avaliação da atividade locomotora após indução local de desmielinização tóxica no tronco encefálico de ratos Wistar / Evaluation of locomotor activity after a local induction of toxic demyelination in the brainstem of Wistar rats

Lesões desmielinizantes induzidas pelo gliotóxico brometo de etídio (BE) têm sido estudadas com o objetivo de permitir a compreensão do limitado processo de reparo mielínico no sistema nervoso central, bem como avaliar estratégias terapêuticas no sentido de acelerar a reconstrução das bainhas de mielina perdidas. Muito embora estudos eletrofisiológicos correlacionando situações de desmielinização e remielinização experimental sejam bem estabelecidos, os efeitos comportamentais não têm sido adequadamente investigados. Neste estudo, foram analisadas ultra-estruturalmente as lesões desmielinizantes e a atividade locomotora de ratos submetidos à indução focal de desmielinização pelo modelo do BE na superfície ventral do tronco encefálico, mediante observação de sua movimentação e controle motor durante a travessia de uma trave elevada de madeira (beam walking test). Foi observada a ocorrência de deficiências locomotoras até 31 dias pós-injeção de BE, constatando-se ainda que a subseqüente remielinização estava relacionada com o retorno da função perdida.

Delayed Schwann cell and oligodendrocyte remyelination after ethidium bromide injection in the brainstem of Wistar rats submitted to streptozotocin diabetogenic treatment

Schwann cell disturbance followed by segmental demyelination in the peripheral nervous system occurs in diabetic patients. Since Schwann cell and oligodendrocyte remyelination in the central nervous system is a well-known event in the ethidium bromide (EB) demyelinating model, the aim of this investigation was to determine the behavior of both cell types after local EB injection into the brainstem of streptozotocin diabetic rats. Adult male Wistar rats received a single intravenous injection of streptozotocin (50 mg/kg) and were submitted 10 days later to a single injection of 10 æL 0.1 percent (w/v) EB or 0.9 percent saline solution into the cisterna pontis. Ten microliters of 0.1 percent EB was also injected into non-diabetic rats. The animals were anesthetized and perfused through the heart 7 to 31 days after EB or saline injection and brainstem sections were collected and processed for light and transmission electron microscopy. The final balance of myelin repair in diabetic and non-diabetic rats at 31 days was compared using a semi-quantitative method. Diabetic rats presented delayed macrophage activity and lesser remyelination compared to non-diabetic rats. Although oligodendrocytes were the major remyelinating cells in the brainstem, Schwann cells invaded EB-induced lesions, first appearing at 11 days in non-diabetic rats and by 15 days in diabetic rats. Results indicate that short-term streptozotocin-induced diabetes hindered both oligodendrocyte and Schwann cell remyelination (mean remyelination scores of 2.57 ± 0.77 for oligodendrocytes and 0.67 ± 0.5 for Schwann cells) compared to non-diabetic rats (3.27 ± 0.85 and 1.38 ± 0.81, respectively).

Behaviour of oligodendrocytes and Schwann cells in an experimental model of toxic demyelination of the central nervous system

Oligodendrocytes and Schwann cells are engaged in myelin production, maintenance and repairing respectively in the central nervous system (CNS) and the peripheral nervous system (PNS). Whereas oligodendrocytes act only within the CNS, Schwann cells are able to invade the CNS in order to make new myelin sheaths around demyelinated axons. Both cells have some limitations in their activities, i.e. oligodendrocytes are post-mitotic cells and Schwann cells only get into the CNS in the absence of astrocytes. Ethidium bromide (EB) is a gliotoxic chemical that when injected locally within the CNS, induce demyelination. In the EB model of demyelination, glial cells are destroyed early after intoxication and Schwann cells are free to approach the naked central axons. In normal Wistar rats, regeneration of lost myelin sheaths can be achieved as early as thirteen days after intoxication; in Wistar rats immunosuppressed with cyclophosphamide the process is delayed and in rats administered cyclosporine it may be accelerated. Aiming the enlightening of those complex processes, all events concerning the myelinating cells in an experimental model are herein presented and discussed

The Guillain-Barré syndrome following dengue fever

A 44 year old female presented with fever, muscle aches, rash and a low platelet count. IgM antibody to dengue virus was positive. Two weeks later she developed a flaccid areflexic quadriparesis. Nerve conduction studies showed a predominantly demyelitinating sensory motor polyneuropathy consistent with Guillain-Barré syndrome. Despite the relatively common occurrence of dengue fever, an associated polyradiculoneuropathy is distinctly uncommon.

Desmielinizaçäo e remielinizaçäo após múltiplas injeçöes intramedulares de brometo de etídio em ratos Wistar / Demyelination and remyelination after multiple intramedullary injections of ethidium bromide in Wistar rats

O modelo de desmielinizaçäo do brometo de etídio foi utilizado para estudar a reaçäo do sistema nervoso central frente a múltiplos episódios de desmielinizaçäo tóxica. Foram utilizados 27 ratos Wistar, submetidos a 2, 3 ou 4 injeçöes de 1mul de soluçäo 0,1 por cento de brometo de etídio (19 ratos) ou de soluçäo salina 0,9 por cento (8 ratos) em diferentes pontos da medula espinhal. Os intervalos entre as injeçöes variaram de 28 a 42 dias. Dez dias após a última injeçäo os animais foram perfundidos com glutaraldeído 2,5 por cento. As medulas espinhais foram avaliadas pela macroscopia, microscopia óptica de cortes semifinos e microscopia eletrônica de transmissäo. As lesöes foram caracterizadas por desmielinizaçäo primária focal, com preservaçäo das estruturas vasculares, e variavam em tamanho e características histológicas. Remielinizaçäo pode ser observada, ou näo, de acordo com o tipo de lesäo. Como consequência das injeçoös múltiplas e sequenciais de brometo de etídio, o sistema nervoso central pareceu modificar sua capacidade de responder a um estímulo inflamatório, mas näo variou seu padräo de remielinizaçäo.

Polineuropatía inflamatoria desmielinizante crónica: presentación de 6 casos / Chronic inflammatory demyelinating polyneuropathy: report of 6 cases

Chronic inflammatory demyelinating polyneuropathy is a heterogeneous disease characterized by symmetrical motor and sensitive alterations, absence of tendom reflexes and increased cerebrospinal fluid protein levels. We report 6 patients with the disease (3 males) aged 41 to 70 years old. Four had tha classical presentation and two had an asymmetrical paresis, that predominated in superior limbs. These patients had proximal block with scarce prolongation of distal nerve conduction velocity. In all patients, underlying illnesses were discarded with a full diagnostic work up. Subjects were followed from 2 to 14 months after the diagnosis. In all, treatment with steroids improved muscle strength and sensivity

Compromiso del sistema nervioso periférico en la infección por el virus de la inmunodeficiencia humana / Peripheral nervous system involvement in human immunodeficiency virus infection

El compromiso del SNP en la infección por el VIH/SIDA es frecuente, apareciendo como vulnerables prácticamente todas sus estructuras conformantes. Existen entidades clínicas bien caracterizadas desde el punto de vista clínico, neurofisiológico y patológico. Las diferentes neuropatías asociadas a VIH/SIDA tienden a expresarse preferentemente en determinados períodos de la infección; la polineuropatía desmielinizante inflamatoria suele ser precoz, pudiendo ser la primera manifestación de infección. La expresión de la polineuropatía simétrica distal, la neuropatía más frecuente, aumenta en la medida que la infección progresa. La polirradiculoneuritis progresiva y la mononeuritis múltiple son más frecuentes en el período avanzado de la infección. En un mismo paciente pueden estar presente simultanéamente o en forma desfasada más de una entidad en particular, así como coexistir con compromisos primarios y secundarios del SNC. El objetivo de esta presentación es revisar el espectro de las alteraciones neuromusculares relacionadas a la infección por VIH incluyendo neuropatías y miopatías para facilitar y propiciar su inclusión en los algoritmos de diagnóstico diferencial clínico de los compromisos neuromusculares en general

Imunologia na esclerose múltipla / Immunolgy in multiple sclerosis

A patogênese e a etiologia da esclerose múltipla (EM) é desconhecida. A EM é adquirida por indivíduos geneticamente susceptíveis. A doença se desenvolve devido à quebra da impermeabilidade da barreira hematoencefálica. Esta alteraçäo causa edema e inflamaçäo. O papel do sistema imune e, em particular, dos linfócitos T é revisto

Síndrome de Guillain-Barré "axonal" / \"Axonal\" Guillain -Barré syndrome

A síndrome de Guillain-Barré "axonal" caracteriza-se por uma apresentaçäo clínica semelhante à das neuropatias inflamatórias desmielinizantes agudas, distinguindo-se destas pela rapidez de evoluçäo, gravidade e mau prognóstico. Duas säo as possibilidades fisiopatológicas; degeneraçäo axonal distal ou lesäo desmilinizante distal. O autor apresenta uma revisäo dos principais aspectos da literatura

Neuropatia motora mutifocal / Multifocal motor neuropathy

A Neuropatia Motora Multifocal apresenta um quadro clínico superponível ao das doenças do neurônio motor, mas uma avaliaçäo eletroneuromiográfica cuidadosa revela indícios de desmielinizaçäo focal das fibras motoras, permitindo a individualizaçäo desta afecçäo e autorizando terapia imunossupresora