Does the type of electrode affect the electromyoneurographic parameters in rats?

Abstract Purpose: To evaluate if the type of electrode (needle vs. surface) affects the electromyoneurography parameters in rats. Methods: Twenty male rats were anesthetized, then compound muscle action potential were recorded using a Neuropack S1 MEB- 9400©. All animals were submitted to two electroneuromyography analysis: first with surface electrode and then by needle electrode. We evaluated the latency, amplitude, duration and area of the negative peak of the gastrocnemius and cranial tibial muscles. Results: There were no significant differences between the groups in the mean of duration, latency, amplitude or area of the negative peak in gastrocnemius and cranial tibial muscles. Conclusion: The type of electrode does not affect the electroneuromyography parameters.

Is phrenic nerve conduction affected in patients with difficult-to-treat asthma? / A neurocondução do nervo frênico está alterada na asma de difícil controle?

ABSTRACT Objective The aim of this study was to obtain data on phrenic neuroconduction and electromyography of the diaphragm muscle in difficult-to-treat asthmatic patients and compare the results to those obtained in controls. Methods The study consisted of 20 difficult-to-treat asthmatic patients compared with 27 controls. Spirometry, maximal inspiratory and expiratory pressure, chest X-ray, phrenic neuroconduction and diaphragm electromyography data were obtained. Results The phrenic compound motor action potential area was reduced, compared with controls, and all the patients had normal diaphragm electromyography. Conclusion It is possible that a reduced phrenic compound motor action potential area, without electromyography abnormalities, could be related to diaphragm muscle fiber abnormalities due to overload activity.

RESUMO Objetivo O objetivo do presente estudo foi obter dados da neurocondução do frênico e exame com agulha do diafragma em pacientes com asma de difícil controlee comparar com um grupo normal. Métodos O estudo consiste em realizar radiografia de tórax, espirometria, pressão máxima inspiratória e expiratória, neurocondução do nervo frênico e eletromiografia do músculo diafragma em 20 pacientes asmáticos de difícil controle e comparar com 27 controles. Resultados Encontramos redução da área do potencial de ação muscular composto do nervo frênico e a eletromiografia do musculo diafragma estava normal em todos os pacientes. Conclusão É possível que a redução da área do potencial de ação muscular composto do nervo frênico nos pacientes com asma de difícil controle associado a eletromiografia normal do músculo diafragma esteja relacionada as alterações da fibra muscular do mesmo devido à sobrecarga de atividade.

Phrenic nerve conduction studies: normative data and technical aspects / Aspectos técnicos e normatização da neurocondução do nervo frênico

ABSTRACT Objective: The aim of the present study was to define normative data of phrenic nerve conduction parameters of a healthy population. Methods: Phrenic nerve conduction studies were performed in 27 healthy volunteers. Results: The normative limits for expiratory phrenic nerve compound muscle action potential were: amplitude (0.47 mv - 0.83 mv), latency (5.74 ms - 7.10 ms), area (6.20 ms/mv - 7.20 ms/mv) and duration (18.30 ms - 20.96 ms). Inspiratory normative limits were: amplitude (0.67 mv - 1.11 mv), latency (5.90 ms - 6.34 ms), area (5.62 ms/mv - 6.72 ms/mv) and duration (13.77 ms - 15.37 ms). Conclusion: The best point of phrenic nerve stimulus in the neck varies among individuals between the medial and lateral border of the clavicular head of the sternocleidomastoid muscle and stimulation of both sites, then choosing the best phrenic nerve response, seems to be the appropriate procedure.

RESUMO Objetivo: O objetivo do presente estudo foi definir os dados normativos de condução do nervo frênico de uma população saudável. Métodos: Foram realizados estudos de condução do nervo frênico em 27 voluntários saudáveis. Resultados: Os limites normais do potencial de ação muscular composto do nervo frênico durante a expiração foram: amplitude (0.47 mv - 0.83 mv), latência (5.74 ms - 7.10 ms), área (6.20 ms/mv - 7.20 ms/mv) e duração (18.30 ms - 20.96 ms). E durante a inspiração os limites normais foram: amplitude (0.67 mv - 1.11 mv), latência (5.90 ms - 6.34 ms), área (5.62 ms/mv - 6.72 ms/mv) e duração (13.77 ms - 15.37 ms). Conclusão: O melhor ponto de estímulo do nervo frênico no pescoço varia entre a borda medial e lateral da cabeça clavicular do músculo esternocleidomastóideo. Estimular ambos os locais e escolher a melhor resposta do nervo frênico parece ser o procedimento mais adequado.

Alteración de las fibras finas A-delta por entrampamiento del nervio mediano en la muñeca utilizando el período silente cutáneo / The impairment of A-delta fibers in median nerve compression at the wrist, using the cutaneous silent period

El síndrome del túnel carpiano (STC) es una neuropatía por entrampamiento a nivel de la muñeca que cursa con dolor, parestesias y disestesias dolorosas. El diagnóstico electrofisiológico se basa en el estudio de la neuroconducción de las fibras gruesas. Nuestra hipótesis consiste en la existencia del compromiso de las fibras nerviosas finas y que este compromiso se correlaciona con el grado de gravedad. Se evaluaron retrospectivamente 69 manos correspondientes a 47 pacientes, varones y mujeres (edad media 53.8, rango 22-87 años) y como grupo contro, 21 manos correspondientes a los lados asintomáticos de estos casos. Se realizaron estudios de neuroconducción motora, sensitiva y ondas F para clasificar a las manos según el grado de gravedad. Se realizó el período silente cutáneo (PSC) en todas las manos. Se evaluaron latencias medias y duraciones medias del PSC. Las latencias medias se hallaron significativamente prolongadas en las manos con neuropatía (84.3 ± 16.3 mseg) con respecto a las manos sin neuropatía (74.8 ± 11.6 mseg), p < 0.05. Las latencias medias se hallaron más prolongadas en las manos con neuropatía de mayor gravedad (p < 0.05). En los 3 pacientes con neuropatía grado más grave no se halló el PSC. Se demostró el compromiso de las fibras finas A-delta en los pacientes con STC, con mayor compromiso a mayor severidad. El PSC puede usarse como complemento de los estudios de neuroconducción motora y sensitiva.

Carpal tunnel síndrome (CTS) is an entrapment neuropathy of the median nerve at the wrist, that leads to pain, paresthesia and painful dysesthesia. The electrophysiological diagnosis is based upon nerve conduction studies which evaluate thick nerve fibers. Our hypothesis is that there is an additional dysfunction of small fibers in CTS, which correlates with the degree of severity of the neuropathy. A retrospective study of 69 hands that belonged to 47 patients of both sexes (mean age 53.8, years, range 22-87) was performed, and, as a control group, 21 hands which corresponded to the asymptomatic side of those patients were evaluated. Motor and sensory conduction studies, as well as F-waves were performed to classify the neuropathy according to the degree of severity. Cutaneous silent period (CSP) was elicited in all hands. Mean onset latencies and durations of CSP were evaluated. Mean onset latencies were significantly prolonged in neuropathic hands (84.3 ± 16.3 msec) compared to asymptomatic hands (74.8 ± 11.6 msec) (p < 0.05). Mean latencies of the CSP were even prolonged (p < 0.05) in hands affected by a more severe neuropathy. In the 3 hands with most severe neuropathy, a CSP could not be elicited. In CTS an impairment of A-delta fibers was recorded through the CSP. The more severe the neuropathy is, the more impairment of A-delta fibers can be found. CSP may be assessed as a complement of motor and sensory nerve conduction studies in this neuropathy.

Sensory disturbance and polyneuropathy in rheumatoid arthritis patients with foot deformity / Perturbações sensitivas e polineuropatia em pacientes com artrite reumatoide com deformidade do pé

Abstract Introduction Our aim in this study was to present the results of sensory evaluation tests and electrophysiological evaluations in rheumatoid arthritis (RA) patients with foot deformity and to determine their relation with general health status and lower extremity functionality. Materials and methods Fifty-one patients with RA diagnosis and foot deformity were included in the study. Demographic and disease characteristics of the patients were recorded, and a detailed neurological examination was performed. Superficial sensation, pain, heat, vibration, and two-point discrimination sensation were evaluated in each foot, and their sum was used to determine the sensory deficits index (SDI) of 0–10. The presence of polyneuropathy was evaluated with electrophysiological methods. The Health Assessment Questionnaire and mobility and walking subscales of the Arthritis Impact Measurement Scales-2 were used to assess general health status and lower extremity functionality, respectively. According to the sensory examination and electromyography results, patients were compared in terms of their general health status and lower extremity functional status. Results Sensory disturbance was detected in 39 patients (74%) during the examination; however, 27 patients (52.9%) had polyneuropathy determined electrophysiologically. In patients with sensory deficits, statistically significant deterioration was detected in general health and foot functionality, including mobility and walking, when compared to patients with a normal sensory evaluation. Conclusions Even in the presence of normal electrophysiological tests, sensory dysfunction alone seems to be associated with severe disability in general health status and foot functionality when compared to patients with a normal sensory examination.

Resumo Introdução O objetivo deste estudo foi apresentar os resultados dos testes de avaliação sensitiva e do exame eletrofisiológico em pacientes com artrite reumatoide (AR) com deformidade do pé e determinar a sua relação com o estado geral de saúde e o aspecto funcional dos membros inferiores. Materiais e métodos Foram incluídos no estudo 51 pacientes com diagnóstico de AR e deformidade do pé. Foram registradas as características demográficas e da doença de cada indivíduo e foi feito um exame neurológico detalhado. Foi avaliada a sensibilidade superficial, dolorosa, térmica e vibratória e aplicado o teste de discriminação de dois pontos em cada um dos pés. A soma dos escores foi usada para determinar o índice de déficits sensitivos (IDS) de 0‐10. A presença de polineuropatia foi avaliada com métodos eletrofisiológicos. Foram usados o Health Assessment Questionnaire e as subescalas mobilidade e deambulação da Arthritis Impact Measurement Scales‐2 para avaliar o estado geral de saúde e o aspecto funcional de membros inferiores, respectivamente. De acordo com os resultados dos exames de eletromiografia e de sensibilidade, os pacientes foram comparados em relação ao seu estado geral de saúde e estado funcional de membros inferiores. Resultados Foram detectados distúrbios sensitivos em 39 pacientes (74%) durante o exame; contudo, 27 (52,9%) tinham polineuropatia determinada eletrofisiologicamente. Em pacientes com déficits sensitivos, foi detectada deterioração estatisticamente significativa no estado geral de saúde e no aspecto funcional do pé, inclusive na mobilidade e deambulação, quando comparados com os pacientes com uma avaliação sensitiva normal. Conclusão Mesmo na presença de testes eletrofisiológicos normais, a disfunção sensitiva isolada parece estar associada a incapacidade grave no estado geral de saúde e ao aspecto funcional do pé em comparação com pacientes com um exame sensitivo normal.

Clinical and neurophysiological features of the hereditary neuropathy with liability to pressure palsy due to the 17p11. 2 deletion / Aspectos clínicos e neurofisiológicos de pacientes com a neuropatia hereditária com a susceptibilidade à pressão associada à deleção 17p11. 2

ABSTRACT The hereditary neuropathy with liability to pressure palsies (HNPP) is an autossomal dominant disorder manifesting recurrent mononeuropathies. Objective Evaluate its clinical and nerve conduction studies (NCS) characteristics, searching for diagnostic particularities. Method We reviewed the neurological manifestations of 39 and the NCS of 33 patients. Results Family history was absent in 16/39 (41%). The onset complaints were weakness in 24, pain in 6, sensory deficit in 5 and paresthesias in 4. Pain was seen in 3 other patients. The following neuropathy patterns were found: multiple mononeuropathy (26), mononeuropathy (7), chronic sensorimotor polyneuropathy (4), chronic sensory polyneuropathy (1) and unilateral brachial plexopathy (1). NCS showed a sensorimotor neuropathy with focal conduction slowing in 31, two had mononeuropathy and another brachial plexopathy. Conclusion HNPP presentation is variable and may include pain. The most frequent pattern is of an asymmetrical sensory and motor neuropathy with focal slowing at specific topographies on NCS.

RESUMO A neuropatia hereditária com susceptibilidade à pressão (HNPP) é uma doença autossômica dominante que manifesta mononeuropatias recorrentes. Objetivo Avaliar as características clínicas e os estudos da condução nervosa (ECN) procurando particularidades diagnósticas. Método Revisamos as características clínicas de 39 e os ECN de 33 pacientes. Resultados História familiar ausente em 16/39 (41%). As manifestações iniciais foram: fraqueza em 24, dor em 6, déficit sensitivo em 5 e parestesias em 4. Dor foi referida por outros 3 pacientes. Os seguintes padrões de neuropatia foram observados: mononeuropatia múltipla (26), mononeuropatia (6), polineuropatia sensitivo-motora (4), polineuropatia sensitiva (1) e plexopatia braquial unilateral (1). Os ECN mostraram uma neuropatia sensitivo-motora com redução focal da velocidade de condução em 31, dois tinham mononeuropatia e outro plexopatia braquial. Conclusão A apresentação da HNPP é variável e pode incluir dor. O padrão mais frequente é o de uma neuropatia sensitivo-motora assimétrica com alentecimentos focais da condução em topografias específicas nos ECN.

Peripheral neurppathy electrophysiological screening in children with celiac disease / Triagem eletrofisiológica de neuropatia periférica em crianças com doença celíaca

Background The involvement of the peripheral nervous system in children with celiac disease is particularly rare. Objective The aim of this study was to assess the need for neurophysiological testing in celiac disease patients without neurological symptoms in order to detect early subclinical neuropathy and its possible correlations with clinical and demographic characteristics. Methods Two hundred and twenty consecutive children with celiac disease were screened for neurological symptoms and signs, and those without symptoms or signs were included. Also, patients with comorbidities associated with peripheral neuropathy or a history of neurological disease were excluded. The remaining 167 asymptomatic patients as well as 100 control cases were tested electro-physiologically for peripheral nervous system diseases. Motor nerve conduction studies, including F-waves, were performed for the median, ulnar, peroneal, and tibial nerves, and sensory nerve conduction studies were performed for the median, ulnar, and sural nerves with H reflex of the soleus muscle unilaterally. All studies were carried out using surface recording electrodes. Normative values established in our laboratory were used. Results Evidence for subclinical neuropathy was not determined with electrophysiological studies in any of the participants. Conclusion In this highly selective celiac disease group without any signs, symptoms as well as the predisposing factors for polyneuropathy, we did not determine any cases with neuropathy. With these results we can conclude that in asymptomatic cases with celiac disease electrophysiological studies are not necessary. However, larger studies with the electrophysiological studies performed at different stages of disease at follow-ups are warranted. .

Contexto O envolvimento do sistema nervoso periférico em crianças com doença celíaca é particularmente raro. Objetivo O objetivo do presente estudo foi avaliar a necessidade de testes neurofisiológicos em pacientes com doença celíaca sem sintomas neurológicos, a fim de detectar neuropatia subclínica precoce e suas possíveis correlações com características clínicas e demográficas. Métodos Duzentos e vinte crianças consecutivas com doença celíaca foram pesquisadas para os sinais e sintomas neurológicos, e foram incluídos somente aqueles sem sintomas ou sinais. Além disso, os portadores de comorbidades associadas à neuropatia periférica ou história de doença neurológica também foram excluídos. Os 167 pacientes assintomáticos, bem como 100 casos controles foram testados electrofisiologicamente para doenças do sistema nervoso periférico. Estudos de condução nervosa motora, incluindo ondas F foram realizados para os nervos medianos, ulnar, fibular e tibiais; realizaram-se estudos de condução sensorial para o nervo mediano, ulnar, e nervos surais com reflexo H do músculo sóleo unilateralmente. Todos os estudos foram realizados utilizando gravação por eletrodos de superfície. Foram usados valores normativos estabelecidos em nosso laboratório. Resultados Não foi determinada evidência de neuropatia subclínica com estudos eletrofisiológicos em qualquer um dos participantes. Conclusão Neste grupo altamente seletivo de pacientes com doença celíaca sem quaisquer sinais, sintomas, bem como os fatores predisponentes para a polineuropatia, não se determinou qualquer caso com neuropatia. Com estes resultados, pode-se concluir que, em casos assintomáticos com doença celíaca os estudos eletrofisiológicos não são necessários. No entanto, são necessários maiores estudos eletrofisiológicos realizados em diferentes fases da doença. .

Small fiber dysfunction in patients with Wilson's disease / Disfunção de fibras finas em pacientes com doença de Wilson

Objective: Patients with Wilson’s disease (WD) may develop a wide variety of neuropsychiatric symptoms, but there are few reports of autonomic dysfunction. Here, we described evidence of small fiber and/or autonomic dysfunction in 4 patients with WD and levodopa-responsive parkinsonism. Method: We reviewed the charts of 4 patients with WD who underwent evaluation for the presence of neuromuscular dysfunction and water-induced skin wrinkling test (SWT). Results: Two men and 2 women (33±3.5 years) with WD were evaluated. They all had parkinsonism at some point during their disease course. Parkinsonism on patient 4 almost completely subsided with treatment of WD. Two patients had significant sensory and 2 significant autonomic complaints, including syncopal spells. NCS/EMG was normal in all but SWT was abnormal in half of them (mean 4-digit wrinkling of 0.25 and 1). Discussion: A subset of patients with WD exhibit evidence of abnormal skin wrinkling test (small fiber neuropathy). .

Objetivo: Pacientes com doença de Wilson (DW) podem desenvolver uma ampla variedade de sintomas neuropsiquiátricos, mas existem poucos relatos de disfunção autonômica. Aqui, nós descrevemos evidência de disfunção de fibras finas/autonômica em 4 pacientes com DW e parkinsonismo responsivo à levodopa. Método: Nós revisamos os prontuários de 4 pacientes com DW que foram submetidos a avaliação neuromuscular e ao teste de quantificação do enrugamento cutâneo (TEC). Resultados: Dois homens e 2 mulheres (33±3,5 anos) com DW foram avaliados. Todos apresentaram parkinsonismo durante o curso de sua doença. Parkinsonismo no paciente 4 quase completamente desapareceu com tratamento da DW. Dois pacientes apresentaram queixas sensitivas e 2 apresentaram queixas autonômicas significativas incluindo episódios de síncope. Eletroneuromiografia foi normal em todos e TEC foi anormal em metade deles (score do TEC nos 4 dedos de 0,25 e 1). Discussão: Um subgrupo de pacientes com DW apresenta evidência de TEC anormal (neuropatia de fibras finas). .

In Vivo Effects of Adipose-Derived Stem Cells in Inducing Neuronal Regeneration in Sprague-Dawley Rats Undergoing Nerve Defect Bridged with Polycaprolactone Nanotubes

There have been many attempts for regeneration of peripheral nerve injury. In this study, we examined the in vivo effects of non-differentiated and neuronal differentiated adipose-derived stem cells (ADSCs) in inducing the neuronal regeneration in the Sprague-Dawley (SD) rats undergoing nerve defect bridged with the PCL nanotubes. Then, we performed immunohistochemical and histopathologic examinations, as well as the electromyography, in three groups: the control group (14 sciatic nerves transplanted with the PCL nanotube scaffold), the experimental group I (14 sciatic nerves with the non-differentiated ADSCs at a density of 7x105 cells/0.1 mL) and the experimental group II (14 sciatic nerves with the neuronal differentiated ADSCs at 7x105 cells/0.1 mL). Six weeks postoperatively, the degree of the neuronal induction and that of immunoreactivity to nestin, MAP-2 and GFAP was significantly higher in the experimental group I and II as compared with the control group. In addition, the nerve conduction velocity (NCV) was significantly higher in the experimental group I and II as compared with the control group (P=0.021 and P=0.020, respectively). On the other hand, there was no significant difference in the NCV between the two experimental groups (P>0.05). Thus, our results will contribute to treating patients with peripheral nerve defects using PCL nanotubes with ADSCs.

Ulnar sensory-motor amplitude ratio: a new tool to differentiate ganglionopathy from polyneuropathy / Razao de amplitude sensitivo-motora ulnar: novo parametro para diferenciar ganglionopatia de polineuropatia

The objective of this study was to evaluate if the ratio of ulnar sensory nerve action potential (SNAP) over compound muscle action potential (CMAP) amplitudes (USMAR) would help in the distinction between ganglionopathy (GNP) and polyneuropathy (PNP). Methods We reviewed the nerve conductions studies and electromyography (EMG) of 18 GNP patients, 33 diabetic PNP patients and 56 controls. GNP was defined by simultaneous nerve conduction studies (NCS) and magnetic resonance imaging (MRI) abnormalities. PNP was defined by usual clinical and NCS criteria. We used ANOVA with post-hoc Tukey test and ROC curve analysis to compare ulnar SNAP and CMAP, as well as USMAR in the groups. Results Ulnar CMAP amplitudes were similar between GNP x PNP x Controls (p=0.253), but ulnar SNAP amplitudes (1.6±3.2 x 11.9±9.1 × 45.7±24.7) and USMAR values (0.3±0.3 × 1.5±0.9 × 4.6±2.2) were significantly different. A USMAR threshold of 0.71 was able to differentiate GNP and PNP (94.4% sensitivity and 90.9% specificity). Conclusions USMAR is a practical and reliable tool for the differentiation between GNP and PNP. .

O objetivo deste estudo foi avaliar se a razão entre as amplitudes dos potenciais de ação sensitivo (SNAP) e motor (CMAP) do nervo ulnar (USMAR) auxiliaria na distinção entre ganglionopatia (GNP) e polineuropatia (PNP). Métodos Revisamos os estudos de neurocondução e eletromiografia de 18 pacientes com GNP, 33 com PNP diabética e 56 controles. GNP foi definida pela presença simultânea de anormalidades na neurocondução e na ressonância magnética cervical. PNP foi definida por critérios clínicos e neurofisiológicos usuais. Usamos o teste ANOVA com Tukey post-hoc e análise da curva ROC para comparar o SNAP e CMAP ulnares, assim como o USMAR entre os grupos. Resultados As amplitudes dos CMAPs ulnares foram similares entre GNP × PNP × Controles (p=0,253), mas as amplitudes dos SNAPs ulnares (1,6±3,2 × 11,9±9,1 × 45,7±24,7) e os valores de USMAR (0,3±0,3 × 1,5±0,9 × 4,6±2,2) foram significativamente diferentes. Um corte de 0,71 para a USMAR foi capaz de diferenciar GNP de PNP (sensibilidade de 94,4% e especificidade de 90,9%). Conclusões A USMAR é um parâmetro útil e confiável para o diagnóstico diferencial entre GNP e PNP. .

Primary neural leprosy: systematic review / Hanseníase neural primária: revisão sistemática

The authors proposed a systematic review on the current concepts of primary neural leprosy by consulting the following online databases: MEDLINE, Lilacs/SciELO, and Embase. Selected studies were classified based on the degree of recommendation and levels of scientific evidence according to the “Oxford Centre for Evidence-based Medicine”. The following aspects were reviewed: cutaneous clinical and laboratorial investigations, i.e. skin clinical exam, smears, and biopsy, and Mitsuda's reaction; neurological investigation (anamnesis, electromyography and nerve biopsy); serological investigation and molecular testing, i.e. serological testing for the detection of the phenolic glycolipid 1 (PGL-I) and the polymerase chain reaction (PCR); and treatment (classification criteria for the definition of specific treatment, steroid treatment, and cure criteria).

Os autores propuseram-se a realizar uma revisão sistemática em conceitos atuais sobre a hanseníase neural primária, consultando as seguintes bases bibliográficas on-line: MEDLINE, Lilacs/SciELO e Embase. Os estudos selecionados foram classificados conforme o grau de recomendação e o nível de evidência científica de acordo com o “Oxford Centre for Evidence-based Medicine”. Os seguintes temas foram revisados: investigações clínica e laboratorial cutâneas, ou seja, exame, esfregaço e biópsia de pele e reação de Mitsuda; investigação neurológica (anamnese, eletroneuromiografia e biópsia de nervo); investigação sorológica e testes moleculares, ou seja, testes sorológicos para detecção de um glicolipídio fenólico e reação de cadeia de polimerase (PCR) e tratamento (critérios de classificação para definição de tratamento específico, tratamento com esteroides e critérios de cura).

Polirradiculopatía inflamatoria crónica sensitiva / Chronic inflammatory sensory polyradiculopathy

La polirradiculopatía inflamatoria crónica sensitiva es una entidad definida, frecuentemente subdiagnosticada y potencialmente tratable. Debe ser sospechada en pacientes con ataxia sensitiva, estudios de conducción nerviosa normales y una resonancia magnética que muestre engrosamiento y realce con gadolinio de las raíces lumbosacras. Presentamos el caso de un hombre de 57 años de edad con marcada ataxia sensitiva en pierna izquierda. Al examen físico presentaba fuerza conservada, reflejos osteotendinosos disminuidos, tacto fino y superficial reducidos por debajo de las rodillas; abatiestesia y apalestesia en ambos pies. Los estudios de conducción nerviosa eran normales, los potenciales evocados somatosensitivos tibiales con ausencia de respuesta bilateral. El líquido cefalorraquídeo presentaba hiperproteinorraquia sin células. La resonancia magnética mostró engrosamiento y realce con gadolinio de las raíces lumbosacras. El paciente fue tratado con inmunoglobulina endovenosa (IgEV) a 2 g/kg durante 5 días, con buena respuesta. La evolución clínica, la hiperproteinorraquia, el realce de raíces en la resonancia magnética, la buena respuesta a la inmunoterapia y la exclusión de otras causas de ataxia sensitiva fueron compatibles con el diagnóstico de polirradiculopatía inflamatoria crónica sensitiva. Para el diagnóstico de esta enfermedad se requiere la identificación del compromiso aislado de las raíces sensitivas.

Chronic inflammatory sensory polyradiculopathy is a defined entity, frequently underdiagnosed, and potentially treatable. It must be suspected in patients with sensory ataxia, normal nerve conduction studies, and MRI with thickened lumbosacral nerve roots and gadolinium enhancement. We present the case of a 57-year-old man with marked sensory ataxia on his left leg. Examination showed normal strength, decreased knee and ankle jerks. Light touch and pinprick sensations were reduced below the knees. Vibration and joint position sense were absent at the feet. Nerve conduction studies were normal. Tibial sensory evoked potentials disclosed absent responses bilaterally. CSF was acellular with elevated protein. Lumbosacral magnetic resonance showed thickening of roots, with gadolinium enhancement. The patient was treated with IV-Ig, 2 g/kg, for 5 days with improvement of symptoms. The clinical course, elevated CSF protein, the evidence of root enhancement on the MRI, good response to immunotherapy, and the exclusion of other causes of sensory ataxia, were compatible with the diagnosis of chronic inflammatory sensory polyradiculopathy. To diagnose this disease the identification of isolated involvement of the sensory roots is required.

Raphe obscurus neurons participate in thermoregulation in rats / Neurônios do núcleo obscuro da rafe participam da termorregulação em ratos

In mammalian, several evidences suggest that central serotonin participates in thermoregulation. Nucleus raphe obscurus (NRO), a serotonergic nucleus, has been recognized to be the source of generation of various hemodynamic patterns in different behavioral conditions, but its involvement in thermoregulation is unclear. In the present study, extracellular action potentials of NRO neurons were recorded in anesthetized rats, which were submitted to cold and warm stimuli in the tail. The firing rate of the neurons was compared before and after each stimulation. It was found that 59% of the neurons submitted to a cold stimulus trial had a significant increase in their firing frequency, while 48% of the neurons submitted to warm stimulation trial were inhibited. The opposite responses in neuronal activity of NRO units to cooling or heating suggest that these cells are involved in producing the homoeothermic vascular adaptations secondary to changes in cutaneous temperature in the rat tail.

A termorregulação em mamíferos envolve a participação da serotonina. O núcleo obscuro da rafe (NRO), que é serotoninérgico, participa do controle autonômico, mas seu envolvimento na termorregulação é incerto. Neste estudo, registramos potenciais de ação extracelulares de neurônios do NRO em ratos anestesiados nos quais a cauda foi submetida a estímulos de calor ou frio. A frequência de disparo dos neurônios foi comparada antes e depois dos estímulos. O grupo controle não apresentou modificação da frequência de disparo, enquanto que 59% dos neurônios registrados em animais submetidos a estímulo de frio tiveram sua frequência aumentada. Por outro lado, 48% dos animais submetidos a estímulo de calor tiveram sua frequência de disparo diminuída. As respostas opostas da frequência de disparo em neurônios de animais submetidos à estimulação com frio e calor sugere que estes neurônios estejam envolvidos na geração de respostas hemodinâmicas, que são coerentes com a termorregulação nesta espécie.

Reliability study on quantitative detection of extensor digitorum brevis strength with needle electromyography and nerve conduction / 法医学杂志

OBJECTIVE@#To study the objectivity and reliability of needle electromyography and nerve conduction for detection of musculus extensor digitorum brevis strength, which may provide a basis for establishing a quantitative detection of muscle strength in forensic clinical study.@*METHODS@#Forty-four healthy people were enrolled as the subjects, and during toe dorsiflexion, the following items including needle electromyography indexes, motor unit potential (MUP) amplitude, MUP count, recruitment reaction type, and nerve conduction detection indexes, compound muscle action potential (CMAP) amplitude, CMAP latent period and motor nerve conduction velocity (MNCV), were simultaneously detected under the cooperation and disguise condition.@*RESULTS@#Under the cooperation condition, regardless of the same operator or different operators, there were good test-retest reliabilities in MUP amplitude, CMAP amplitude, CMAP latent period and MNCV, while there were normal test-retest reliabilities in MUP count and recruitment reaction type and the repeatability of the same operator was slightly better than the repeatability between different operators. Under the disguise condition, test-retest reliabilities of MUP amplitude, CMAP amplitude, CMAP latent period and MNCV were relatively high, while test-retest reliabilities of MUP count and recruitment reaction type were relatively low.@*CONCLUSION@#There are good test-retest reliabilities in MUP amplitude, CMAP amplitude, CMAP latent period and MNCV, which can be conducive to comparison between different operators and results at various times; MUP count and recruitment reaction type, which can be easily affected by subjectivity of operators and examinees, can be used to differentiate whether an examinee disguises or not. The indexes used to objectively judge muscle strength remain to be further investigated.

The evaluation of SCI by TMS-MEP and its forensic significance / 法医学杂志

OBJECTIVE@#To find an objective and accurate examination for evaluation of spinal cord injury (SCI) in forensic clinical medicine.@*METHODS@#The onset latency of cortex, peak latency of N1, central motor conduction time (CMCT) and wave width of the abductor pollicis brevis and the anterior tibialis were calculated by transcranial magnetic stimulation-motor evoked potential (TMS-MEP). The data of 68 patients suffered from SCI including 23 cervical levels and 45 thoracolumbar levels were collected and compared with that of 30 normal controls.@*RESULTS@#In experimental group, when the muscle strength of the abductor pollicis brevis or the anterior tibialis decreased or disappeared, the onset latency of cortex, the peak latency of N1, and CMCT prolonged and the wave width broadened. And these indexes of grade 2 and 3 muscle strength in experimental group were higher than that in the control group (P < 0.05).@*CONCLUSION@#The TMS-MEP can determine directly and objectively the motor functional status of pyramidal tract of spinal cord in order to provide more accurate and objective evidences in forensic medicine.

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

Efecto del ácido tióctico en los cambios clínicos, neuroconductivos e histopatológicos de la neuropatía diabética sensitivo motora distal / Effect of thioctic acid in the clinical, histopathological and neuroconductivos the distal motor sensory diabetic neuropathy

La polineuropatía diabética es la más común de las complicaciones microvasculares de la diabetes mellitus, siendo causa importante de morbilidad y mortalidad asociada a la enfermedad. Evaluar el efecto del ácido tióctico en los cambios clínicos, neuroconductivos e histopatológicos en la neuropatía diabética sensitivo motora distal. Estudio prospectivo, longitudinal, de intervención terapéutica, en pacientes que acudieron a la consulta externa y unidad cardiometabólica del Servicio de Medicina Interna del Hospital Militar “Dr. Carlos Arvelo”, a quien se les realizó historia clínica con evaluación del score sensitivo-motor, pruebas de neuroconducción y biopsia de piel, con evaluación a la semana n° 1, 4,12, 18 y 24. 30 pacientes diabéticos con criterio clínico de neuropatía diabética sensitivo motora distal. Se observó mejoría de las parestesias a partir de la semana 12 (p <0.05) de la administración del ácido tióctico a dosis de 600mg/día por vía oral. En la neuroconducción hubo aumento de la velocidad de conducción durante el post tratamiento (p<0,05). Se realizaron 12 biopsias de piel: 2 fueron positivas (16,7%) previo tratamiento y 10 negativas (83,3%) con anticuerpo PGP 9,5. En la semana 24 post tratamiento 7 positivas (58,3%) y 5 negativas (41,7%) (p<0,05). Se demostró que el tratamiento con ácido tióctico es efectivo en mejorar los síntomas y la neuroconducción en los pacientes diabéticos con neuropatía sensitivo motora distal.

Diabetic neuropathy is the most common microvascular complication of diabetes mellitus, and a major cause of morbidity and mortality. To evaluate the effect of thioctic acid in the clinical, histopathological neuroconductive and sensory motor diabetic distal neuropathy. Prospective, longitudinal, therapeutic intervention, in patients attending the outpatient and cardiometabolic consultation Internal Medicine; an assessment of sentitivo-motor score was performed and blood chemistry was measured as well as HbA1c. Neuroconduction and skin biopsy with assessment at weeks 1, 4.12, 18 and 24 were done. 30 diabetic patients with clinical criteria of distal motor sensory neuropathy were included. The clinical symptom was paresthesia, which was present from week 12 and showed improvement (p <0.05) at weeks 18 and 24 (p<0.05). Neuroconduction was measured by increased conduction velocity post treatment (p <0.05). Biopsieswere performed in 12 patients; two were positive (16.7%) after treatment and 10 negative (83.3%) for PGP 9.5 antibody. At week 24 of treatment, 7 were positive (58.3%) and 5 negative (41.7%) (p<0.05). We demonstrated effectiveness of thioctic acid after week 12 of treatment.

Combined nerve conduction index in diabetic polyneuropathy / Índice combinado de condução nervosa na polineuropatia diabética

Diabetic polyneuropathy can be confirmed by nerve conduction studies. The data can be analyzed in the form of a combined index instead of individual parameters. METHODS: The combined index included five parameters of nerve conduction studies commonly used for evaluation of polyneuropathies. We evaluated sensitivity in 100 diabetic patients with suspected polyneuropathy, and specificity in 200 non-diabetic patients with suspected lumbosacral radiculopathy. All results were expressed in number of standard deviations (SD). RESULTS: The sensitivity of the combined index was 81 or 74%, and specificity was 97 or 98%, using respectively -2.0 or -2.5 SD as cutoff. The range of sensitivity of the other parameters was 57-65% or 48-56%, and specificity range was 96-98% or 98-100%, using the same criteria. DISCUSSION: The combined index had higher sensitivity and equivalent specificity compared to isolated parameters.

A polineuropatia diabética pode ser confirmada por estudos de condução nervosa. Os dados podem ser analisados por um índice combinado ao invés de parâmetros isolados. MÉTODOS: O índice combinado incluiu cinco parâmetros usados rotineiramente na avaliação de polineuropatias. Avaliamos a sensibilidade em 100 pacientes diabéticos com suspeita de polineuropatia e a especificidade em 200 pacientes não diabéticos com suspeita de radiculopatia lombossacral. Todos os resultados foram expressos em número de desvios-padrão (DP). RESULTADOS: A sensibilidade do índice combinado foi 81 ou 74%, e a especificidade foi 97 ou 98%, usando respectivamente -2,0 ou -2,5 DP como ponto de corte. A sensibilidade dos parâmetros isolados oscilou entre 57-65% ou 48-56%, e a especificidade foi 96-98% ou 98-100%, usando os mesmos critérios. DISCUSSÃO: O índice combinado apresentou melhor sensibilidade e especificidade equivalente aos parâmetros isolados.

Application of needle electromyography and nerve conduction study in forensic appraisal / 法医学杂志

OBJECTIVE@#To explore the application value of needle electromyography (EMG) and nerve conduction study (NCS) in the forensic appraisal; to provide scientific basis for establishing normative and unified assessment methods of the peripheral nerve study in forensic medicine.@*METHODS@#One hundred and sixty-four samples with injured peripheral nerve (injury group) and 138 samples with normal peripheral nerve (control group) were collected and tested with methods of EMG and NCS respectively. The relevance rate of two methods were compared and statistical analysis was performed.@*RESULTS@#In the injury group, there was no statistical difference on the relevance rate between the application of EMG and that of NCS (P > 0.05). In the control group, there was no statistical difference on the negative rate between the two methods (P > 0.05). The false negative rate of the injury group and the false positive rate of the control group were both 0% when using the two methods together.@*CONCLUSION@#When the injured peripheral nerve in forensic appraisal is in doubt, application of both EMG and NCS could disclose truth from falsehood. The accuracy and credibility of identification results could be enhanced.