Eleven patients with diagnosis of possible neurocistycercosis were studied in our Department since 1986. All of them were adults. Eight were Bolivian citizens. The commonest neurological clinical manifestation were seizures and/or headache. Brain CT scans showed cystic lesions and calcifications in 5 patients, only calcifications in 3, enlarged ventricles in 2 and an isolated frontal cystic lesion in 1. Six out of 7 patients who were submitted to spinal fluid ELISA test showed positive response for cysticercosis. Patients were put on praziquantel (50mg/Kg/d) or albendazol (15mg/Kg/d) with good outcome for all them. Surgery was carried on for treatment of enlarged ventricles (2 patients) and for a like-expansive lesion (1 patient). The aim of this work is to underscore the fact that in Buenos Aires city, which previously was not within the endemic latinamerican area for cysticercosis, is now possible to find patients with the neurological manifestations of this parasitosis, most probably due to migration of people coming from the north provinces or from countries situated at its border where the disease is endemic.

Fueron examinados 11 pacientes adultos con el diagnostico presuntivo de neuro-cisticercosis, 8 de ellos provenientes de Bolivia y los restantes del interior de la Argentina. Como manifestacion clinica inicial el 82% de ellos mostro convulsiones y el 73% cefaleas. Ambas alteraciones podían estar combinadas en el mismo paciente o presentarse en forma independiente. La tomografia computada de cerebro evidencio calcificaciones y quistes en 5 enfermos, solo calcificaciones en 3, hidrocefalia en 2 y un unico quiste en 1. En 7 casos se efectuo ELISA en el LCR, de ellos 6 resultaron positivos. El tratamiento medico se hizo en base a la administración de praziquantel o albendazol con buena evolución de los pacientes en todos los casos. El tratamiento quirúrgico fue indicado solo en el caso en que una lesion actuase como masa ocupante con aumento de la presión endocraneana (1 caso) o produjera obstruccion de la circulacon del LCR llevando a una hidrocefalia (2 casos). El estudio presente pretende alertar sobre la posibilidad que nuevas regiones, como la Ciudad de Buenos Aires, puedan ingresar dentro del area endemica latinoamericana a consecuencia de los movimientos migratorios internos y externos y el asentamiento de portadores de la parasitosis en el perimetro urbano.

Foi feita investigação da velocidade de condução motora no nervo ulnar de 70 pacientes em fase crônica da doença de Chagas. Foi verificado que 2,6% deles apresentavam lentificação em grandes axônios motores em segmentos distais e 14% em segmentos proxi-mais: 27% deles apresentavam também condução lentificada em pequenas fibras motoras. Essas observações indicam que alguns pacientes na fase crônica da doença podem desenvolver uma neuropatia motora.

A comprenhensive investigation of nerve motor conduction velocity was carried out in the ulnar nerve of 70 patients in the chronic stage of Chagas disease. It was found that 2.6% of them, had slowness of the large motor axons at distal segments and 14% at proximal segments. Twenty seven percent of them had also slowness of conduction at the smallest motor fibers. These observations signal that some patients in the chronic stage of the infection may develop a motor neuropathy.

Eleven patients with chronic lead intoxication were submitted to somatosensory evoked potential (SEP) studies. All patients demonstrated increased lead blood levels and reduced ALA D activity in red blood cells. Three patients showed delayed spinal arrival (N13 wave), four delayed cortical arrival (N20 wave), and three prolonged central conduction time (time elapsing between N13 and N20 waves) (see table 1). No relationship was found between the abnormal findings and the levels of lead or ALA D. Time of intoxication was not related to the altered electrophysiological features either. The findings reported suggest that, beside the well known peripheral involvement in chronic lead intoxication, some patients may develop central nervous system impairment perhaps related to myelin involvement as suggested by the prolonged SEP central conduction time.

Once pacientes con cifras elevadas de plombemia y disminuidas de delta aminolevulínico dehidrasa (ALA D), fueron estudiados mediante la realización de potenciales evocados somatosensitivos obtenidos por estimulación del nervio mediano, midiendo el ingreso medular, el arribo cortical v el tiempo de conducción central (TCC). Los datos fueron comparados con controles. Se correlacionaron con las deterniinaciones bioquímicas y con el tiempo de exposición al tóxico. Por encima dei limite superior control, se encontro el ingreso medular en tres pacientes, el arribo cortical en cuatro y el TCC en tres. Los valores de N13,N20 y TCC no mostraron correlación con los parâmetros bioquímicos ni con el tiempo de exposición al tóxico. Estos hallazgos sugieren que, si bien la neuropatía periférica condiciona el retraso dei ingreso medular y del arribo cortical, es probable que exista también compromiso de la mielina central en algunos de los pacientes crónicamente expuestos.

Thirty five patients with acute Chagas' disease who demonstrated parasitaemia at the time of the investigation were submitted to a detailed electromyographical study. With their muscles at rest, 12 patients showed fibrillation potentials and/or positive sharp waves. On volitional contraction, 7 had short duration motor unit potentials (MUPs) and low polyphasic MUPs. On motor and sensory nerve fibers conduction studies, 20 disclosed values below the lower control limit within one or more nerves. Finally, 12 patients produced a muscle, decremental response on nerve supramaximal repetitive stimulation. The findings signal that primary muscle involvement, neuropathy and impairement of the neuromuscular transmission, either isolated or combined, may be found in the acute stage of human Chagas' disease.

Treinta y cinco pacientes con el diagnóstico de enfermedad de Chagas en su etapa aguda, todos con parasitemia positiva en el momento de la investigación, fueron sometidos a estudio electromiográfico por técnicas convencionales. En reposo, 12 de ellos mostraron fibrilaciones y/o potenciales positivos. Durante la contracción voluntaria, en 7 pacientes los potenciales de unidad motora eran bifásicos de corta duración y polifásicos de baja amplitud. En 20 se encontró disminución de la velocidad de conducción motora y/o sensitiva en uno o mas de los nervios explorados. Finalmente, 12 pacientes mostraron caida de la amplitud del potencial muscular evocado por estímulo nervioso repetitivo supramáximo. Los hallazgos hechos señalan que durante la fase aguda de la enfermedad de, Chagas en el hombre puede producirse alteración primaria del músculo, neuropatía y compromiso de la transmisión neuromuscular, en forma aislada o combinadas entre si.

An electrophysiological investigation of the state of the neuromuscular transmission (nmt) was carried out in 58 patients with the diagnosis of chronic Chagas' disease. On repetitive supramaximal nerve stimulation it was found that some patients did not show abnormalities, others had decremental muscle responses, others developed enhancement of the muscle evoked potential amplitudes, while some other patients combined both types of pathological responses. The findings suggest that some patients with chronic Chagas' disease develop impairement of nmt, though data obtained in this study do not give information about neither the type of impairement nor the localization (pre or postsynaptic, or both) of the damage.

Cincuenta y ocho pacientes con edades entre los 1 y 58 años, con diagnóstico de enfermedad de Chagas crónica fueron estudiados para evaluar la transmisión neuromuscular. Se estimuló en forma supramáxima el nervio cubital a nivel de muñeca, con registro de electrodos de superficie en hipotenar. Dicha estimulación se realizó a 3 Hz durante 2 segundos y 10 Hz durante 1 segundo en condiciones basales, trás 4 minutos de ejercicio mecánico, luego de 4 minutos de ejercicio mecánico mas isquemia y trás 2 minutos de liberada la isquemia. Se procedió a medir la amplitud del 3, 5, 6 y 10 potencial, que fueron expresados como variación porcentual con respecto al primero al que se le asignó un valor de 100%. Treinta pacientes no evidenciaron diferencias con respecto a la curva obtenida en 20 sujetos controles, 4 mostraron una caida del potencial evocado muscular, 6 una caida del mismo cuando el estímulo se realizó la bajas frecuencias y un incremento cuanto el estímulo fue a altas frecuencias. En los restantes 18 pacientes se observó un incremento del pem. Estos hallazgos sugieren una posible alteración de la transmisión neuromuscular en algunos pacientes que han alcanzado el estadio crónico de la enfermedad de Chagas de probable localización pré y/o post-sináptica.

Seventy five patients with the diagnosis of chronic Chagas' disease were studied by employing EPs techniques. Two of them had delayed arrival of the signal to the Erb's point and one to the spinal cord when looking at SEPs. TWo patients had increment of the time interval between waves 1st and IIIrd, when studying PEATs. These findings were interpreted as due to peripheral nerve fibers damage, a feature described in previous papers. The, most striking finding was the prolonged time interval between waves N13 and N20 (SEPs) found in two patients and between waves IIIrd and Vth (PEAT) seen in 7 affected subjects. These observations suggested the development of some sort of CNS involvement, perhaps related to myelin damage, in patients who reached the chronic state of the infection.

Setenta y cinco pacientes con el diagnóstico de enfermedad de Chagas crónica fueron estudiados con el empleo de los potenciales evocados cerebrales. Tres de ellos tuvieron retardo del arribo de la senal a) punto de Erb ó al ingreso medular en los potenciales evocados somatosensitivos (PESS). Dos pacientes presentaron incremento del intervalo entre las ondas I y III en los potenciales evocados auditivos de tronco (PEAT). Estos hallazgos fueron interpretados como debidos al dano en la fibra nerviosa periférica, un hecho descripto en trabajos previos. El hallazgo mas sorprendente fue la prolongación del intervalo de tiempo entre las ondas N13-N20 en los PESS, hallandose en dos pacientes y entre las ondas III y V en los PEAT en 7 sujetos. Estas observaciones sugieren de algun modo, el compromiso de sistema nervioso central, quizás relacionado al daño de la mielina, en pacientes en estadio crónico de la infección.

A comprehensive electrophysiological examination of the peripheral nervous system was carried out in 12 patients who proved to be toxicated with lead (high lead blood levels, and diminished activity of the delta-aminolevulinate dehydratase, ALA D, in erythrocytes). Maximal motor nerve conduction velocities and terminal latencies were investigated in the median, radial and deep peroneal nerves. Also the amplitude of the evoked muscle response (M wave) was measured in thenar, extensor longus and extensor digitorium brevis muscles. Sensory conduction velocity and amplitude of the nerve compound action potential were measured at the median nerve. Tibialis anterior muscle responses to deep peroneal nerve repetitive stimulation were also explored. Conventional needle electromyogram was performed in the deltoid and tibialis anterior muscles. Slight diminished motor and sensory conduction velocities were found as well as a reduction of the amplitude of the evoked muscle response of the compound sensory action potential. Four out of the 12 patients tested showed either décrémentai or incremental amplitude of the muscle response with nerve repetitive stimulation. A electromyographical diminished interference pattern was found in all patients tested. Most of the remaining motor unit potentials were fragmented or polyphasic. Just one patient disclosed potentials of enhanced duration and amplitude. No relationship was found between blood lead levels or ALA D erythrocytes concentration and the different electrophysiological tests performed, except between reduced ALA D concentration and diminished amplitudes of the M wave and of the sensory compound action potential, and also between ALA D and diminished radial motor conduction velocity. Only a slight relationship was found between timing of toxication and diminished sensory conduction velocity of the median nerve and motor conduction velocity of the radial nerve. Biochemical determination and timing of toxication did not prove to be useful tools for predicting peripheral nervous system damage. The findings suggest that the neuropathy which develops in lead intoxication is probably related mainly to individual predisposition rather than to lead blood levels and ALA D erythrocytes concentration.

Un grupo de 12 pacientes con cifras elevadas de plombemia y disminuidas de ALA D fueron estudiados electrofisiológicamente. Se efectuaron las siguientes determinaciones: amplitud de potencial evocado muscular; latencia distal motora; velocidad de conducción motora en los nervios mediano, ciático poplíteo externo y radial; velocidad de conducción sensitiva y amplitud del potencial evocado sensitivo de nervio en el mediano; exploración electromiográfica convencional; estudio de la transmisión neuromuscular, mediante estimulación repetitiva del nervio ciático popliteo externo a diversas frecuencias, con registro de la amplitud del potencial en músculo tibial anterior. Los datos obtenidos fueron comparados con controles. Se buscaron correlaciones entre las determinaciones bioquímicas y los diferentes hallazgos electrofisiológicos que a su vez se correlacionaron entre si y también con el tiempo de evolución de la intoxicación. Los hallazgos pusieron de manifiesto la presencia de neuropatía axonal junto a moderada desmielinización. La exploración de la transmisión neuromuscular mostró ocasional decremento o incremento de la amplitud del potencial muscular evocado, hechos que suponen cierta participación de la unión neuromuscular. Se halló correlación solamente entre disminución de ALA D y la disminución de las amplitudes del potencial sensitivo del mediano y el evocado muscular del mismo nervio y con la disminución de la VCM del nervio radial. Una débil relación se observó entre el tiempo de exposición y la disminución de la VCS del nervio mediano y VCM del radial. Las determinaciones bioquímicas y el tiempo de exposición transcurridos no probaron ser parámetros sensibles para determinar el grado de afectación del sistema nervioso periférico. El conjunto do hallazgos sugiere que el desarrollo de la neuropatía puede estar ligado a factores individuales de predisposición al daño nervioso.

Um grupo de pacientes com paralisia de Bell foi estudado com o objetivo de descobrir a presença de comprometimento nervoso periférico subclínico. 20 pacientes, 8 homens e 12 mulheres com paralisia de Bell recente como única enfermidade, foram examinados. Em todos os casos outras causas de polineuropatia foram excluídas. Os pacientes foram estudados com exames de líquido cefalorraqueano; latência distal nos nervos faciais do lado afetado e do lado sadio e velocidade de condução motora máxima; latência distal dos nervos mediano e peroneiro direitos. O exame de LCR foi normal em tcdos os casos. A latência do nervo facial foi anormal em todos os pacientes no lado afetado e, no lado clinicamente sadio, diferia significativamente do grupo controle. A metade dos pacientes mostrou valores anormais na velocidade motora máxima e/ou na latência distal de ambos os nervos, como sejam: mediano e peroneiro. Esses resultados estão de acordo com publicações anteriores nas quais se afirma que outros nervos craneanos podem estar afetados na paralisia de Bell. Temos encontrado uma elevada frequência de polineuropatia nesta enfermidade. Estes achados nos levam a crer que, em alguns enfermos, a paralisia de Bell é um componente de uma doença mais disseminada afetando outros nervos craneanos e periféricos.

A group of patients with Bell's palsy were studied in order to disclose the presence of subclinical peripheral nerve involvement. 20 patients, 8 male and 12 female, with recent Bell's palsy as their unique disease were examined, in all cases other causes of polyneuropathy were ruled out. Patients were investigated with CSF examination, facial nerve latencies in the affected and in the sound sides, and maximal motor nerve conduction velocities, as well as motor terminal latencies from the right median and peroneal nerves. CSF laboratory examination was normal in all cases. Facial nerve latencies were abnormal in all patients in the affected side, and they differed significantly from those of control group in the clinically sound side. Half of the patients showed abnormal values in the maximal motor nerve conduction velocities and motor terminal latencies of the right median and peroneal nerves. These results agree with previous reports which have pointed out that other cranial nerves may be affected in Bell's palsy. However, we have found a higher frequency of peripheral nerve involvement in this entity. These findings, support the hypothesis that in some patients Bell's palsy is the component of a more widespread disease, affecting other cranial and peripheral nerves.

An electrophysiological study was carried out searching for variations in the innervation of the muscles of the hand. For this purpose a simple and non time-consuming technique was designed for stimulating the ulnar and median nerves at the elbow and wrist. Recordings were performed with surface electrodes at the abductor pollicis brevis, adductor digiti minimi and first dorsal interosseus muscles. Several anomalous innervation patterns of the intrinsic muscles of the hand were found, and the innervation of the first dorsal interosseus by the median nerve was the most frequent.

Para investigar las probables variaciones en la inervación de los músculos intrínsecos de la mano y/o la anastomosis entre los nervios mediano y cubital, se estudiaron 24 manos, estimulando en forma percutánea a dichos nervios, registrándose en abductor polliçis brevis (APB), adductor digiti minimi (ADM) y primer interóseo dorsal (PID). Se halló una frecuente inervación del PID por el mediano. Se describe la técnica utilizada, comentando incidência, importancia y probable comportamiento en distintas patologias de las variaciones halladas.

An electrophysiological study has been made of the thenar, hypothenar, soleus and extensor digitorum brevis muscles and their inervation in 90 patients with chronic Chagas' disease. Some of them showed a reduced number of functional motor units with increased size of many of the surviving units. No decremental muscle response was found to repetitive nerve stimulation. Motor and sensory conduction velocities as well as motor terminal latencies were on the normal range. These findings suggested that the muscle changes resulted from a primary defect of the alpha spinal motoneurone soma.

90 pacientes afectados por enfermedad de Chagas crónica fueron estudiados electrofisiológicamente procediéndose a cuantificar Ias unidades motoras actuantes en los músculos de la eminencia tenar, eminencia hipotenar, soleo y extensor corto de los dedos. Se halló que muchos de ellos poseían un número reducido de unidades, en tanto que buena parte de las sobrevivientes mostraban su tamaño aumentado. No se encontró alteración en los valores de velocidad. de conducción nerviosa motora o sensitiva ni tampouco en las cifras de latencia residual motora. La respuesta muscular al estímulo repetitivo del nervio fué igualmente normal. Los hallazgos hechos sugirieron que las alteraciones musculares halladas en estos pacientes pueden, obedecer a la existencia de un defecto primario en el soma de la motoneurona alfa medular.

Gastrocnemius muscle biopsies were performed in 7 subjects with chronic Chagas' disease. On clinical and laboratory grounds the selected patients were judged to be healthy, being the only abnormality found the presence of positive serum tests for Chagas' disease. Fibre type grouping of either type I or type II was observed in 5 of the 7 patients. Furthermore, in 2 of the 5 patients showing muscle fibre groupings, angular fibres reacting with NADH and non-specific sterase were also found. These observations strongly suggest denervation associated with reinervation. This picture often can be observed in the skeletal muscle of patients with well compensated denervatory conditions who do not show clinical evidences of denervation.

En 7 pacientes afectados por enfermedad de Chagas crónica se procedió al estúdio biópsico del músculo gastrocnemio. Los pacientes seleccionados mostraran como única anormalidad la presencia de tests positivos en suero para la enfermedad de Chagas. Agrupamiento de fibras musculares de tipo I y II fué observado en 5 de aquellos; en 2 de estos últimos 5 se encontro, además, fibras anguladas que se teñian intensamente con NADH y esterase no especifica. Las observaciones hechas sugirieron la presencia de denervaçión seguida por reinervación, cuadro que puede ser observado con asiduidad en el músculo esquelético de pacientes con afecciones denervatorias bien compensadas y en los que no existen evidencias clinicas de ese compromiso.

An electromyographical investigation of 80 patients with chronic Chagas' disease was made. It was found that 79% of the studied patients had EMG manifestations of old and chronic denervation of the upper and lower limbs without clinical features of nervous system involvement.

Fueron estudiados 80 pacientes portadores de la forma crónica de la enfermedad de Chagas mediante el empleo de técnicas convencionales de electromiografia de detección. Los hallazgos evidenciaron en el 79% de los pacientes signos de denervación antigua tanto en miembros superiores como inferiores, aúnque con predominio en estos últimos. En ningún caso hubo manifestacionrs clínicas concomitantes.

Foi feito estudo eletromiográfico do curto extensor dos dedos e dos músculos tenares e hipotenares em 25 pacientes com polimíosite crônica e aguda. Foi encontrada diminuição no número de unidades motoras funcionantes em alguns pacientes com polimíosite crônica e somente em um caso de polimíosite aguda. Os tamanhos das unidades restantes sugerem que os resultados podem ser explicados em termos de um envolvimento primário dos músculos especialmente na polimiosite aguda, ao passo que na polimiosite crônica ocorre uma combinação de acometimento primário e neurogênico.

An electrophysiological study has been made of the extensor digitorum brevis, thenar and hypothenar muscles in 25 patients with chronic and acute polymyositis. It was found a reduction of the number of functioning motor units in some patients with chronic polymyositis and only in one of those affected by acute polymyositis. The sizes of the surviving units suggested that the results could be explained in terms of a primary muscle involvement mainly in acute polymyositis, while in chronic polymyositis a combination of primary and neurogenic involvement of muscle fibers might take place.