Scielo RSS <![CDATA[Arquivos de Neuro-Psiquiatria]]> http://www.scielo.br/rss.php?pid=0004-282X19830003&lang=en vol. 41 num. 3 lang. en <![CDATA[SciELO Logo]]> http://www.scielo.br/img/en/fbpelogp.gif http://www.scielo.br <![CDATA[<b>Proper microsurgical nerve suture may impede Wallerian degeneration of completely transected nerves</b>: <b>an electron microscopic study</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300001&lng=en&nrm=iso&tlng=en Electron microscopic findings on the nerve of the biventer cervicis muscle of the chick, which was completely transected and immediately after submitted to an adequate microsurgical nerve suture, confirmed our previous statement that proper microsurgical nerve suture may impede the Wallerian degeneration that normally occurs in the distal segment of a completely transected nerve.<hr/>Neste trabalho experimental foi utilizado, como o fizemos7 em 1968, o nervo do músculo biventer cervicis do pintainho (Fig. 1). Os nervos transeccionados ao nível do tendão intermédio do músculo e propositadamente não suturados, ou acidentalmente mal suturados, apresentaram, como esperado, degeneração Walleriana total do segmento distal e conseqüente desnervação do ventre distal do músculo. Os nervos, transeccionados e imediatamente suturados com técnica microcirúrgica fascicular adequada, apresentaram, em nível de microscopia eletrônica, de 7 1/2 hs. a 2 meses pós-operatório, numerosas fibras nervosas mielínicas e amielínicas íntegras (Figs. 2 a 9), além, naturalmente, de fibras nervosas em diferentes e progressivas fases de degeneração Walleriana. Os ventres distais dos músculos cujos nervos foram operados com sucesso apresentavam coloração e aspecto normais, respondiam a estímulos mecânicos e, em cortes histológicos para microscopia óptica, exibiram numerosas placas motoras íntegras. A afirmação que fizemos em trabalhos anteriores - "a degeneração Walleriana total que normalmente ocorre em segmentos distais de nervos completamente transeccionados pode ser parcialmente evitada através de neurorrafias, com técnica microcirúrgica fascicular adequada" - é agora documentada em nível de microscopia eletrônica. <![CDATA[<b>Morphometry study on pre and post-hatching nerve cell bodies of lumbar spinal ganglia of <i>Gallus domesticus</i></b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300002&lng=en&nrm=iso&tlng=en A cytomorphometric study was performed in lumbar spinal ganglia neurons of Gallus domesticus on the 10th and 18th incubation days and 8th, 35th, 61st, and 120th post-hatching days. The absolute volume of nucleus and relative volume of cytoplasm were respectively estimated by the Bach² caryometric method and by point-counting volumetry, carried out in 0.5mm thick araldite sections. The relative volume, the surface-to-volume ratio and the total surface of RER, SER, mitochondria, dense bodies, Golgi complex and the relative volume of hyaloplasm inside and outside the Nissl bodies were estimated from electronmicrographs by the Weibel et al.58 method. The conclusions were: a) there was an increase of the cell volume and a decrease of the nucleo-cytoplasmic ratio, particularly between the first two ages; b) the relative volumes of RER and SER change inversely with respect to each other: the RER increases before hatching, decreasing progressively afterwards; the changes of relative volume of dense bodies are similar to those of the RER, and the mitochondria show relatively small variations concerning the same parameter; c) the relative volume of hyaloplasm inside the Nissl bodies decreases while those outside increases; d) the surface-to-volume ratio drops sharply for all organelles from the 10th to the 18th day of incubation; after hatching, a tendency to increase is observed; e) the membrane surface-to-cytoplasmic volume ratio decreases for all organelles from the 10th to the 18th day of incubation; after hatching, this ratio increases slightly for mitochondria and Golgi complex, sharply for SER, dropping for dense bodies. The RER values alternate regularly.<hr/>Foi realizado estudo citomorfométrico em neurônios de gânglios espinais lumbares de Gallus domesticus no 10º e 18º dias de incubação e no 8º, 35º, 61º e 120º dias após a eclosão. Os volumes absoluto do núcleo e relativo do citoplasma foram estimados, respectivamente, pelo método cariométrico de Bach² e pela volumetria de contagem de pontos, em cortes de araldite de 0.5mm. O volume relativo, a relação superfície/volume e a superfície total do RER e SER, mitocôndria, corpos densos, complexo de Golgi e volume relativo de hialoplasma, no interior e fora dos corpos de Nissl, foram estimados a partir de eletron-micrografias, pelo método de Weibel et al.58. As conclusões foram: a) houve aumento do volume celular e diminuição da relação núcleo-citoplasmática, particularmente entre as duas primeiras idades; b) os volumes relativos do RER e SER variam inversamente, entre si: o RER aumenta antes da eclosão, decrescendo, após, progressivamente; as variações do volume relativo dos corpos densos são semelhantes àquelas do RER e as mitocôndrias mostram relativamente, pequenas variações, no que concerne ao mesmo parâmetro; c) o volume relativo do hialoplasma no interior dos corpos de Nissl diminui, enquanto o situado no interior, aumenta; d) a relação superfície/volume decresce muito para todas as organelas, do 10º para o 18º dia de incubação; após a eclosão foi observada tendência à elevação; e) a relação superfície de membrana volume citoplasmático cai para todas as organelas, do 10º para o 18º dia de incubação; após a eclosão, esta relação diminui levemente para mitocôndrias e complexo de Golgi, fortemente para o SER, caindo, também, para corpos densos. Os valores do RER alternam-se, regularmente. <![CDATA[<b>Evaluation of central and peripheric factors in muscular fatigue</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300003&lng=en&nrm=iso&tlng=en Se estúdio la fatiga muscular en 13 sujetos normales; para ello, fueron sometidos a un esfuerzo sostenido durante 10 minutos previo y posterior, al cual se realizo la medición de la onda M máxima. Durante el esfuerzo y cada 2 minutos, se obtuvieron cuantificaciones de la frecuencia y duración de las ondas positivas y negativas del EMG. Los resultados, mostraron diferencias significativas de estos valores, en función del tiempo de esfuerzo realizado, mientras que las mediciones de la onda M máxima inicial y final, no fueron diferentes, todo lo cual lleva a jerarquizar el factor central como el más importante en el desarrollo de fatiga, bajo nuestras condiciones de estudio, que son además de sencilla aplicación clínica.<hr/>Muscular fatigue was investigated in 13 healthy people by employing a simple device which comprises a computer on line with a conventional EMG equipment able to automatically measure the frequency and duration of free-run EMG recording. The procedure was carried out in the extensor digitorum brevis muscle by using surface electrodes throughout 10 minutes of voluntary maximal effort. The maximal M wave as well as the muscle response to repetitive nerve maximal stimulation was also explored at the beginning and at the end of the experiment. It was observed a decrease of the potentials frequency discharge and an increase of their duration without major changes in the M wave amplitude neither in the muscle response to the repetitive nerve discharge. The findings pointed out to the central factors as the main responsible for the development of muscular fatigue. <![CDATA[<b>Muscular fatigue mechanisms in pyramidal lesions</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300004&lng=en&nrm=iso&tlng=en Para evaluar algunos de los componentes de la fatiga muscular en el daño piramidal, se seleccionó un grupo de 15 pacientes con hemiparesia faciobraquiocrural de severidad variable, los cuales fueron sometidos a un esfuerzo muscular, durante el cual se evaluaron los cambios de la frecuencia y duración de los potenciales positivos y negativos del EMG, asi como los sufridos por la onda M máxima al principio y fin del mismo. El estudio fue realizado en el lado parético, el contralateral y en un grupo control de voluntarios sanos, comparándose los resultados de los 3 grupos. Las curvas de frecuencia y duración del lado parético, el sano y el control mantuvieron las mismas tendencias, así como fue homologable el comportamiento de la onda M máxima en los 3 casos, lo cual indica que en la espasticidad, debido a daño de la vía piramidal, al igual que en la población normal, bajo las presentes condiciones de estudio, es el factor central el condicionante principal en el desarrollo de fatiga muscular.<hr/>Muscular fatigue mechanisms were partially analyzed in patients with pyramidal lesions by using a computer device on line with a conventional electromyograph. Both the normal and the affected side were compared with control groups. The recordings were done throughout a ten minutes period and the maximal M wave was also measured at the starting and at the end of the procedure. The findings suggested that central events play a major role in the development of muscular fatigue in spastic muscles due to pyramidal damage. <![CDATA[<b>Muscular fatigue mechanisms in neuropathies and myopathies</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300005&lng=en&nrm=iso&tlng=en Utilizando un método de cuantificación del electromiograma, se investigaron parte de los mecanismos centrales y periféricos responsables de la fatiga muscular en enfermos crónicamente denervados y en pacientes con compromiso muscular primitivo. Se observó en los denervados que los mecanismos de fatiga muscular, no difieren mayormente de los observados en el grupo de sujetos sanos, por el contrario, en los miopáticos a más del componente central, existen otros de orden periférico, tales como la pérdida de unidades motoras funcionantes durante el esfuerzo y el bloqueo temporario de la transmisión neuromuscular, que contribuye al desarrollo de la fatiga.<hr/>In a group of patients chronically denervated and other with primary muscle involvement a search was made for mechanisms involved in the muscular fatigue. It was found that there was no major differences between patients chronically denervated and controls, while in those others with primary muscle disorders a loss of functional motor units during effort and a transient impairment of neuromuscular transmission play a role together with the central events normally occuring in fatigue. <![CDATA[<b>Cerebrospinal fluid protein concentration gradient</b>: <b>1. Mechanism of origin</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300006&lng=en&nrm=iso&tlng=en Foi feito estudo do mecanismo de origem do gradiente ventriculo-lombar de concentração das proteínas totais do LCR baseado no comportamento da taxa das proteínas totais e do título da reação de fixação de complemento para cisticerco em pacientes com neurocisticercose em atividade. O aumento concomitante da taxa das proteínas totais e da intensidade da reação imunitária, em amostras simultâneas cisternal e lombar do LCR de pacientes com comunicação livre no espaço subaracnóideo espinhal, e as grandes elevações simultâneas destes dados da semiologia no LCR lombar de pacientes que apresentaram bloqueio do espaço subaracnóideo espinhal, indicam que o gradiente de concentração das proteínas ao longo do neuro-eixo resulta da saída seletiva de água.<hr/>In normal conditions there is a concentration gradient of proteins along the neuraxis. From a low level in the ventricles, ranging from 5 to 15 mg/100 ml, to an intermediate level in the cisterna magna, the protein content reaches its highest level in the lumbar sac, 12 to 44 mg/100 ml. Several mechanisms were considered to elucidate the origin of this gradient but many investigators think that the progressive increase of the protein concentration is best explained by the transfer of proteins from serum to the cerebrospinal fluid due to the relatively raised permeability of blood-cerebrospinal fluid barrier in the spinal subarachnoid space. This paper presents a study of the protein concentrations in cisternal and lumbar cerebrospinal fluid samples of patients with neurocysticercosis in activity. The 11 patients of the first group had free subarachnoid space communication between the cisterna magna and the lumbar sac; the 6 patients of the second group had a complete block of the subarachnoid space between these two levels. In every cerebrospinal fluid specimen the quantitative complement fixation test for cysticercus was performed and the titer determined in order to make an assessment of the central nervous system humoral immune response. The analysis of the data of this investigation shows that the concentration gradient of proteins is evident in the cerebrospinal fluid of patients with patency of the spinal subarachnoid space, and the ratio of concentrations of protein contents in simultaneous cisternal and lumbar samples was similar to that one observed in normal individuals. This gradient is also detected when the intensity of the humoral immune response is determined by quantitative complement fixation test for cysticercus in simultaneous cisternal and lumbar specimens. After the onset of spinal subarachnoid block, the confront of the results of the tests in cerebrospinal fluid samples, obtained before and after the blockage, shows a large increase both in the total protein content as well as the intensity of the humoral immune response, in the lumbar level. The similar increases both in protein concentration and titer of cysticercus complement fixation test in the lumbar fluid, in comparison with the cisternal fluid, in patients with patent spinal subarachnoid space, and the large simultaneous and similar increases in both protein content and titer of the cysticercus complement fixation test in the lumbar fluid of patients with spinal subarachnoid block are in disagreement with the usual explanation of the origin mechanims of the gradient. If the large increase in the protein content were the consequence of its transfer from serum to cerebrospinal fluid, it would have determined a decrease in the intensity of the immune response because of the negative or low complement fixation test titer usually verified in blood serum. Due to the poor systemic repercussion of the humoral immune response, the blood serum has a low reagin concentration or no reagin at all. Thus, it would have resulted in a decrease of the reagin concentration, instead of the constant increase observed in the spinal fluid of the great majority of the patients of the two groups. The comparative study of the protein contents and of the degrees of the intensity of the immune response in the cerebrospinal fluid of patients with neurocysticercosis, with patency of the cistern-lumbar subarachnoid space, and with spinal subarachnoid space block, suggests that the cerebrospinal fluid protein concentration gradient is the consequence of the scape of water from the fluid. <![CDATA[<b>Cerebrospinal fluid protein concentration gradient</b>: <b>2 - Effect of the ventriculoatrial shunt</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300007&lng=en&nrm=iso&tlng=en Em trabalho anterior, baseado no estudo comparativo do LCR cisternal e lombar de pacientes com neurocisticercose em atividade, com permeabilidade normal ou com bloqueio do espaço subaracnóideo espinhal, foi apresentada evidência de que o gradiente de concentração das proteínas ao longo do neuro-eixo tem sua origem na saída seletiva de água. Em prosseguimento a esse estudo foi feito este segundo trabalho apoiado nas observações de 11 pacientes com neurocisticercose, que apresentaram no decurso de sua doença hipertensão endocraniana grave que exigiu a derivação ventrículo-atrial do LCR para permitir a sobrevivência. Após a intervenção cirúrgica, foi observada uma melhoria surpreendente do quadro clínico. O exame do LCR lombar revelou aumento da taxa das proteínas totais na maioria dos pacientes, verificando-se valores muito elevados, quando comparados estes resultados com aqueles existentes antes da derivação ventrículo-atrial. Entretanto, neste segundo exame foi observada atenuação da reação inflamatória, revelada pela melhoria da modificação citológica. Este acréscimo da concentração das proteínas totais resultou muito provavelmente da menor movimentação do LCR no espaço subaracnóideo, como consequência do desvio para o sangue de grande parte do LCR produzido. A diminuição da intensidade da resposta imunitária e da reação inflamatória do sistema nervoso central, avaliada pelo exame de LCR feito depois da cirurgia, indica que a drenagem ventricular e a conseqüente normalização da pressão endocraniana permitiram uma melhoria evidente das condições encefálicas. Uma pesquisa bibliográfica especializada não revelou ter sido assinalada esta ocorrência de um acentuado aumento da taxa das proteínas totais no LCR subaracnóideo após a derivação ventrículo-atrial ou peritoneal, quer em pacientes com neurocisticercose, quer em pacientes com outros processos não tumorais que evoluem para o bloqueio do quarto ventrículo ou cisternas da base.<hr/>On a previous paper, based upon the data obtained from comparative studies of cerebrospinal fluid samples of two groups of patients with neuro-cysticercosis in activity, one with patency, the other one with blockage of the spinal subarachnoid space, evidence was presented that the concentration gradient of proteins along the neuraxis was the consequence of the escape of water from cerebrospinal fluid. The second paper is a continuance of that one. The material for this survey consisted of the clinical records of 11 patients with neurocysticercosis who during the course of the disease presented severe intracranial hypertension which required ventriculoatrial shunt as an emergency operation in order to allow survival. After surgery, it was observed a marked improvement in the clinical picture. Later, it was noticed a large increase in the protein content of the spinal fluid of the majority of the patients, as compared with the results verified prior to surgery. However, in these spinal fluid samples the increase in protein content was observed without a simultaneous rise in cell count, suggesting an improvement in the inflammatory condition. It seems very likely that this large elevation of the protein content in the subarachnoid fluid is the consequence of a reduction in the spinal fluid flow rate due to the ventricle-venous shunt. The decrease in the intensity of the central nervous system immune response and inflammatory reaction, estimated on the basis of the spinal fluid changes after surgery, indicates a restored normal state of cerebrospinal fluid pressure due to the beneficial effect of the ventriculoatrial shunt. In search of the world literature we have been unable to find previous description of this marked increase in the protein content of the spinal fluid after ventriculoatrial or peritoneal shunts, either in patients with neurocysticercosis or in patients with other disease processes of no tumoral origin that later develloped blockage of the fourth ventricle and basal cisterns. <![CDATA[<b>Spontaneous thrombosis of a giant aneurysm after extirpation of a hemodinamically related arteriovenous malformation</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300008&lng=en&nrm=iso&tlng=en É registrado o caso de um paciente que apresentava um aneurisma gigante da artéria cerebral média esquerda, e volumosa malformação vascular hemodinamicamente relacionada. Após extirpação da malformação vascular, houve desaparecimento espontâneo do aneurisma, conforme demonstrado em angio-grafias repetidas uma semana, seis meses e um ano após cirurgia. Atribuímos o fato à redução do fluxo sanguíneo regional cerebral, após a extirpação da malformação vascular, e a tendência natural desses aneurismas gigantes se trombosarem parcialmente.<hr/>A case of a patient with a giant aneurysm of the left middle cerebral artery and a huge arteriovenous malformation hemodinamically related is reported. Complete thrombosis of the aneurysm was observed after extirpation of the arteriovenous malformation as shown by angiography one week, six months and a year post-operatively. Reduction of the regional cebral blood flow after extirpation of the arteriovenous malformation and the natural tendency of these giant aneurysms to partially thrombose were to be the explanation for our result. <![CDATA[<b>Rhabdomyolysis and myoglobinuria</b>: <b>a case report</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300009&lng=en&nrm=iso&tlng=en Os autores registram um caso de mioglobinúria confirmada pela eletroforese de proteínas da urina. A eletromiografia revelou alterações de tipo polimiosítico. A biópsia muscular do deltóide esquerdo mostrou processo inflamatório muscular inespecífico. O tratamento instituído baseou-se em repouso, hiperhidratação e alcalinização da urina. Os autores enfatizam a importância do diagnóstico pela relativa benignidade do processo, que tende para a cura se forem superadas as sérias complicações da fase aguda, a iatrogenia medicamentosa e por procedimentos diagnósticos desnecessários no início da doença.<hr/>A case of paroxysmal myoglobinuric myopathy diagnosed by urinary protein electrophoresis is reported. Electromyograph (EMG) study done 20 days after onset of the symptoms demonstrated a polimyositic feature with normal motor and sensitive nervous conduction pattern. A biopsy of the left deltoid muscle performed 3 days after the EMG showed only an inespecific inflammation. The treatment included bed rest, parenteral fluids administration in excess (about 3,000 ml per day) and urinary alkalinization. Recovery started on the 2nd day of hospitalization when the patient showed progressive decrease in pain and weakness; furthermore the patient reacquired his mobility. The myoglobinuria start diminishing in intensity on the third day. The clinical picture of the patient continued to improve in the next 2 weeks, and slow recovery of the muscular strength occurred during the following two months of convalescence. In the present case we were not able to stablish the etiology of the illness. Nevertheless the clinical history suggests that infection, allergy and/or parenteral drug administration have had some role in precipitating the disease. This case report reinforces the concept that it is necessary an early and precise diagnosis of this syndrome followed by an adequate therapeutic approach avoiding the unnecessary use of drugs which "per se" could aggravate the disease. <![CDATA[<b>Fanconi's anaemia</b>: <b>report of two cases in the same family</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300010&lng=en&nrm=iso&tlng=en São registrados dois casos, ocorridos na mesma família, de anemia hipoplásica de Fanconi, nos quais um dos irmãos apresenta a tríade completa de anemia, malformações esqueléticas e quebras cromossômicas e, o outro, apenas as quebras cromossômicas.<hr/>Two familial cases of Fanconi's anaemia are reported. The princeps case shows the complete triad of anaemia, squeletic malformations and chromossome breakage, while in his brother only chromossome breakages were found. <![CDATA[<b>Polyneuropathy caused by Parathion</b>: <b>clinical, eletrophysiological and histological study of a case</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300011&lng=en&nrm=iso&tlng=en Estudamos um paciente com quadro clínico rebelde, produzido por intoxicação pelo Parathion. Foi observado um fenômeno miotônico transitório, não descrito na literatura revisada. A constatação de cifras de AchE eritrocitária baixas e de colinesterase plasmática normais, indicou que era portador de déficit congênito de AchE, esclarecendo-se a evolução crônica do seu quadro. O fenômeno miotônico associado ao quadro clínico, eletrofisiológico, histológico e bioquímico fazem deste paciente um modelo clínico, de etiologia conhecida, da discutida síndrome de Isaacs.<hr/>A case of 38 year old man who worked with organochlorinated and Parathion during 5 years is reported. His follow-up was up to 2 years. The onset of the disease was characterized by cholinergic signs, headache, loss of weight, trembling, miokimias, fasciculations, ataxia, myotonic phenomena (in hands only) and motor sensitive peripheral polyneuropathy (affecting the lower limbs symmetrically). Low concentrations of blood cholinesterases confirmed the etiology. Myotonic phenomena disappeared spontaneuosly 6 months after the initial observation. One year later, the concentration of erytrocyte acetilcholinesterase was found to be low and plasma cholinesterase was normal, suggesting that the patient was carrier of a congenital deficiency of acetilcholinesterase. in literature relationship between myotonia and intoxication due to organophosphorus was not found. The whole clinical picture, cholinergic symptoms, transitory myotonic phenomena and spontaneous motor activity could be explained by an excess of acetilcholine. Eletromyography (EMG) in the first observation showed neuromuscular transmission blocking characterized by deficiency or absence of voluntary activity, unexcitability of fibular nerves, with fibrilations and positive peaks as described previously with Mipafox (another organophosphorus agent). During 2 years of observation numerous end-plates potentials of muscular fibres persisted in the EMG. A progressive increase in voluntary activity showed by unit motor potential of almost normal amplitude and very increased duration was observed. No potentials of reinnervation were noted. The results of EMG were explained as disturbances of neuromuscular transmission associated with moderate signs of denervation The Eaton-Lambert's test and the stimulation of a single unit motor potential confirmed disorder of neuromuscular synapses. The histochemistry of brachial biceps showed scattered atrophic and angulated type I and II fibres. Teased-fibres preparations showed nerve fibres with B, C, and G alterations as defined by Dyck et al. indicating axonal degeneration. These results were according to velocity of sensitive conduction. The conduction velocity of fibular nerves was strongly delayed during all the evolution indicating serious disorders of motor nerves myelin. We think that intoxication by organophosphorus should not be expressed as an identical alteration of both motor and sensitive nerves. The association of myotonic phenomena with such clinical, electrophysiological and histological picture is characteristic of the Isaac's syndrome model with known etiology. <![CDATA[<b>Análises de livros</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300012&lng=en&nrm=iso&tlng=en Estudamos um paciente com quadro clínico rebelde, produzido por intoxicação pelo Parathion. Foi observado um fenômeno miotônico transitório, não descrito na literatura revisada. A constatação de cifras de AchE eritrocitária baixas e de colinesterase plasmática normais, indicou que era portador de déficit congênito de AchE, esclarecendo-se a evolução crônica do seu quadro. O fenômeno miotônico associado ao quadro clínico, eletrofisiológico, histológico e bioquímico fazem deste paciente um modelo clínico, de etiologia conhecida, da discutida síndrome de Isaacs.<hr/>A case of 38 year old man who worked with organochlorinated and Parathion during 5 years is reported. His follow-up was up to 2 years. The onset of the disease was characterized by cholinergic signs, headache, loss of weight, trembling, miokimias, fasciculations, ataxia, myotonic phenomena (in hands only) and motor sensitive peripheral polyneuropathy (affecting the lower limbs symmetrically). Low concentrations of blood cholinesterases confirmed the etiology. Myotonic phenomena disappeared spontaneuosly 6 months after the initial observation. One year later, the concentration of erytrocyte acetilcholinesterase was found to be low and plasma cholinesterase was normal, suggesting that the patient was carrier of a congenital deficiency of acetilcholinesterase. in literature relationship between myotonia and intoxication due to organophosphorus was not found. The whole clinical picture, cholinergic symptoms, transitory myotonic phenomena and spontaneous motor activity could be explained by an excess of acetilcholine. Eletromyography (EMG) in the first observation showed neuromuscular transmission blocking characterized by deficiency or absence of voluntary activity, unexcitability of fibular nerves, with fibrilations and positive peaks as described previously with Mipafox (another organophosphorus agent). During 2 years of observation numerous end-plates potentials of muscular fibres persisted in the EMG. A progressive increase in voluntary activity showed by unit motor potential of almost normal amplitude and very increased duration was observed. No potentials of reinnervation were noted. The results of EMG were explained as disturbances of neuromuscular transmission associated with moderate signs of denervation The Eaton-Lambert's test and the stimulation of a single unit motor potential confirmed disorder of neuromuscular synapses. The histochemistry of brachial biceps showed scattered atrophic and angulated type I and II fibres. Teased-fibres preparations showed nerve fibres with B, C, and G alterations as defined by Dyck et al. indicating axonal degeneration. These results were according to velocity of sensitive conduction. The conduction velocity of fibular nerves was strongly delayed during all the evolution indicating serious disorders of motor nerves myelin. We think that intoxication by organophosphorus should not be expressed as an identical alteration of both motor and sensitive nerves. The association of myotonic phenomena with such clinical, electrophysiological and histological picture is characteristic of the Isaac's syndrome model with known etiology. <![CDATA[<b>In Memoriam</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1983000300013&lng=en&nrm=iso&tlng=en Estudamos um paciente com quadro clínico rebelde, produzido por intoxicação pelo Parathion. Foi observado um fenômeno miotônico transitório, não descrito na literatura revisada. A constatação de cifras de AchE eritrocitária baixas e de colinesterase plasmática normais, indicou que era portador de déficit congênito de AchE, esclarecendo-se a evolução crônica do seu quadro. O fenômeno miotônico associado ao quadro clínico, eletrofisiológico, histológico e bioquímico fazem deste paciente um modelo clínico, de etiologia conhecida, da discutida síndrome de Isaacs.<hr/>A case of 38 year old man who worked with organochlorinated and Parathion during 5 years is reported. His follow-up was up to 2 years. The onset of the disease was characterized by cholinergic signs, headache, loss of weight, trembling, miokimias, fasciculations, ataxia, myotonic phenomena (in hands only) and motor sensitive peripheral polyneuropathy (affecting the lower limbs symmetrically). Low concentrations of blood cholinesterases confirmed the etiology. Myotonic phenomena disappeared spontaneuosly 6 months after the initial observation. One year later, the concentration of erytrocyte acetilcholinesterase was found to be low and plasma cholinesterase was normal, suggesting that the patient was carrier of a congenital deficiency of acetilcholinesterase. in literature relationship between myotonia and intoxication due to organophosphorus was not found. The whole clinical picture, cholinergic symptoms, transitory myotonic phenomena and spontaneous motor activity could be explained by an excess of acetilcholine. Eletromyography (EMG) in the first observation showed neuromuscular transmission blocking characterized by deficiency or absence of voluntary activity, unexcitability of fibular nerves, with fibrilations and positive peaks as described previously with Mipafox (another organophosphorus agent). During 2 years of observation numerous end-plates potentials of muscular fibres persisted in the EMG. A progressive increase in voluntary activity showed by unit motor potential of almost normal amplitude and very increased duration was observed. No potentials of reinnervation were noted. The results of EMG were explained as disturbances of neuromuscular transmission associated with moderate signs of denervation The Eaton-Lambert's test and the stimulation of a single unit motor potential confirmed disorder of neuromuscular synapses. The histochemistry of brachial biceps showed scattered atrophic and angulated type I and II fibres. Teased-fibres preparations showed nerve fibres with B, C, and G alterations as defined by Dyck et al. indicating axonal degeneration. These results were according to velocity of sensitive conduction. The conduction velocity of fibular nerves was strongly delayed during all the evolution indicating serious disorders of motor nerves myelin. We think that intoxication by organophosphorus should not be expressed as an identical alteration of both motor and sensitive nerves. The association of myotonic phenomena with such clinical, electrophysiological and histological picture is characteristic of the Isaac's syndrome model with known etiology.