A Study of Somatic Nerve Functions in Diabetic and Normal Persons.

This hospital-based case-control study was undertaken among 50 diabetic cases and 50 non-diabetic controls of Burdwan to evaluate neurophysiological changes. Neurophysiological assessment was done with nerve conduction velocity, amplitude and latency of median nerve motor and sensory component of upper arms and tibial motor and sural sensory part of lower limbs. NCV and amplitude had negative correlation where latency had positive correlation with age and duration of diabetes. Independent t-test was done to compare NCV and amplitude among cases and controls and results showed diminished values in cases than controls (p< 0.001). This study reflected that early diagnosis and management of neuropathy by neurophysiological test may retard the progression of neuropathy in diabetic persons.

Study of variations in medial sural cutaneous nerve, lateral sural cutaneous nerve and peroneal communicating nerve.

The sural nerve complex includes the Medial sural cutaneous nerve (MSCN), Lateral sural cutaneous nerve (LSCN), Peroneal communicating nerve (PCN) and Sural nerve. The sural nerve is the most frequently used donor nerve for peripheral nerve grafting. LSCN can be an alternative to sural nerve in situations requiring a limited length of nerve graft material, the peroneal communicating nerve may also be harvested. Fifty lower limb specimens were dissected and data was collected. The study included 16 male and 9 female cadavers. MSCN was observed in all 50 specimens, out of which 74% specimens had normal course and 22% had a transmuscular course. LSCN was present in 82% of specimens. PCN was arising from Common Peroneal Nerve (CPN) directly in 16% and as a common trunk with LSCN in 14% of specimens. PCN was absent in 28% of cases. So knowledge of variation in these nerves will help the surgeons while considering these nerves for nerve grafting.

Valores de referencia de los estudios de Neuroconducción de miembros inferiores en adultos jóvenes / Young adults' lower limb neuroconduction study reference values

Objetivo Establecer valores de referencia de los estudios de neuroconducción de los nervios peroneo, tibial y sural en un grupo de adultos jóvenes. Materiales y Métodos Se realizaron neuroconducciones en 155 sujetos asintomáticos, de los nervios tibial, peroneo y sural, usando técnicas convencionales actuales y previo consentimiento informado. Se obtuvieron valores de referencia presentados con promedios, desviaciones estándar, percentiles y su correlación con parámetros como edad, peso y estatura a través de un análisis bivariado de correlación lineal utilizando la prueba de Spearman. Resultados Para el nervio peroneo el promedio de la latencia distal fue de 3,6ms (DE 0,4), la amplitud fue de 6,1mV (DE 2,0) y la velocidad de conducción 54,8m/s (DE 4,2). Para el nervio tibial el promedio de la latencia distal fue de 3,5ms (DE 0,4), la amplitud fue de 16,7mV (DE 4,7) y la velocidad de conducción 53m/s (DE 3,8). Para el nervio sural el promedio de la latencia al pico fue de 3,4ms (DE 0,3), la amplitud fue de 21,3mV (DE 5,0). El límite superior de la variación normal de la latencia lado a lado para el nervio peroneo y tibial fue de 0,8ms (promedio + 2DE) y para el nervio sural fue de 0,4ms (promedio + 2DE). Se encontró relación estadísticamente significativa con variables como peso, estatura y edad. Conclusiones Los valores obtenidos pueden ser utilizados en los laboratorios de electrofisiología de nuestro país como referencia en la evaluación de pacientes con patologías musculoesqueléticas y con diferentes tipos de polineuropatía.

Objective Establishing reference values for neuroconduction studies regarding the peroneal, tibial and sural nerves in a group of young adults. Materials and Methods Neuroconduction was tested (also known as nerve conduction velocity (NCV) tests) on 155 asymptomatic subjects' tibial, peroneal and sural nerves using current conventional techniques, after informed written consent had been obtained. Reference values were obtained and presented as averages, standard deviations and percentiles, along with their correlation with parameters such as age, weight and height, via bivariate analysis of linear correlation using Spearman's rank correlation test. Results Peroneal nerve average distal latency was 3.6ms (0.4 SD), amplitude 6.1mV (2.0 SD) and conduction velocity 54.8m/s (4.2 SD). Average tibial nerve distal latency was 3.5ms (0.4 SD), amplitude 16.7mV (4.7 SD) and conduction velocity 53m/s (3.8 SD). Average sural nerve peak latency was 3.4ms (0.3 SD) and amplitude 21.3V (5.0 SD). Peroneal and tibial nerve upper limit of normal side to side variation was 0.8ms (average+2DE) and 0.4ms (average + 2 SD) for the sural nerve. A statistically significant relationship was found with variables such as weight, height and age. Conclusions The values so obtained could be used in Colombia's electrophysiology laboratories as reference in evaluating patients' suffering musculoskeletal pathologies and different types of polyneuropathy.

Can Wistar rats be used as the normotensive controls for nerve morphometry investigations in spontaneously hypertensive rats (SHR)? / Ratos Wistar podem ser utilizados como os controles normotensos dos ratos espontaneamente hipertensos (SHR) em investigações morfométricas de nervos periféricos?

PURPOSE: We compared the sural nerve morphology among Wistar (WR), Wistar-Kyoto (WKY) and Spontaneously hypertensive (SHR) rats, including the nerve fascicles and myelinated fibers morphometry. METHODS: Age matched (20 weeks) female WR (N=6), WKY (N=6) and SHR (N=7) had their right and left sural nerves removed, embedded in epoxy resin, and observed by light microscopy. Morphometric analysis was performed with the aid of computer software. RESULTS: Despite presenting the same age, WR were heavier than WKY and SHR, as were SHR compared to WKY. Systolic arterial pressure was higher in SHR compared to WR, but no differences between SHR and WKY or WR and WKY were observed. The sural nerves were morphometrically symmetric between proximal and distal segments on the same side and between sides in all strains with no differences in the myelinated fiber number. Schwann cell number and density were smaller in SHR and G ratio was larger in SHR, indicating that SHR have thinner myelinated fibers. CONCLUSION: Sural nerve morphology is similar between WKY and WR, allowing the use of WR as the SHR controls in morphological investigations involving peripheral neuropathies.

OBJETIVO: Comparar a morfologia do nervo sural em ratos Wistar (WR), Wistar Kyoto (WKY) e espontanemanete hipertensos (SHR), incluindo a morfometria dos fascículos e fibras mielínicas. MÉTODOS: Os nervos surais direito e esquerdo de WR (N=6), WKY (N=6) e SHR (N=7), com 20 semanas de idade foram removidos e preparados para inclusão em resina epóxi e microscopia de luz. A morfometria foi realizada com o auxílio de um programa de computador. RESULTADOS: Apesar de apresentarem a mesma idade, WR são mais pesados que os WKY e SHR. Ainda, SHR são mais pesados que os WKY. A pressão arterial sistólica foi significativamente maior nos SHR comparados aos WR, sem diferença entre WKY e SHR ou WR e WKY. Os nervos surais são morfometricamente simétricos entre segmentos proximal e distal e entre lados direto e esquerdo nas três diferentes linhagens, sem diferença no número de fibras mielínicas. O número e a densidade de células de Schwann foram menores e a razão G foi maior nos SHR, indicando a presença de fibras mielínicas com bainha mais fina. CONCLUSÃO: A morfologia do nervo sural é semelhante ente WR e WKY, permitindo o uso de WR como controles dos SHR nas investigações envolvendo neuropatias periféricas.

Carpal tunnel syndrome in the elderly: nerve conduction parameters / Síndrome do túnel do carpo em idosos: parâmetros de condução nervosa

Objective: To establish nerve conduction parameters for carpal tunnel syndrome (CTS) electrodiagnosis in the elderly. Method: Thirty healthy subjects (65-86 years), 9 male and 21 female, were studied. Routine median and ulnar sensory and motor nerve conduction studies, median mixed palmar latency, comparative latency techniques median to ulnar (sensory, mixed and motor lumbrical-interossei), median to radial (sensory), and combined sensory index (CSI) were performed in both hands. Results: The upper limits of normality (97.5 percent) were: median sensory distal latency 3.80 ms (14 cm); median motor distal latency 4.30 ms (8 cm); median palmar latency 2.45 ms (8 cm); lumbrical-interossei latency difference 0.60 ms (8 cm); comparative median to radial 0.95 ms (10 cm); comparative median to ulnar 0.95 ms (14 cm); comparative palmar median to ulnar 0.50 ms (8 cm); and CSI 2.20 ms. Sensory and mixed latencies were measured at peak. Conclusion: Our results establish new nerve conduction parameters for mild CTS electrodiagnosis in the elderly and will be helpful to reduce the number of false positive cases in this age.

Objetivo: Estabelecer parâmetros de condução nervosa para o eletrodiagnóstico da síndrome do túnel do carpo (STC) em idosos. Método: Foram estudadas 30 pessoas idosas (65-86 anos) saudáveis. Foi realizado estudo de condução nervosa sensitiva e motora rotineira dos nervos mediano e ulnar, latência palmar mista do mediano, técnicas de comparação de latências mediano-ulnar (sensitivo, misto e motor lumbrical-interósseo) e mediano-radial (sensitivo) e índice sensitivo combinado (ISC) em ambas as mãos. Resultados: Os limites superiores de normalidade, 97,5 por cento foram: latência distal sensitiva do mediano 3,80 ms (14 cm); latência distal motora do mediano 4,30 ms (8 cm), latência palmar do mediano 2,45 ms (8 cm), diferença de latência lumbrical-interósseo 0,60 ms (8 cm), comparação mediano-radial 0,95 ms (10 cm), comparação mediano-ulnar 0,95 ms (14 cm), comparação mediano-ulnar palmar 0,50 ms (8 cm) e ISC 2,20 ms. As latências sensitivas e mistas foram medidas no pico. Conclusão: Nossos resultados estabelecem novos valores de condução nervosa para o eletrodiagnóstico da STC leve em idosos.

Anomalous course of the medial sural cutaneous nerve and its clinical implications

The sural nerve is formed by the union of the medial sural cutaneous nerve, which is a branch of the main trunk (the tibial nerve), and the common fibular communicating branch of the lateral sural cutaneous nerve, which is a branch of the common fibular nerve. Anatomical variations in the formation of the sural nerve are common, although the topographical localization of this nerve is constant. In this report, we describe three cases of an anomalous course of the medial sural cutaneous nerve which descended through the gastrocnemius via a tunnel formed within the muscle. Such anatomical variations of the sural nerve are clinically important when evaluating sensory axonal loss in distal axonal neuropathies since sural nerve mononeuropathy is less likely to occur.

Estudo eletrofisiológico do nervo cutâneo dorsal lateral: aplicabilidade técnica e valores de referência / Electrophysiological study of the lateral dorsal cutaneous nerve: technical applicability and normal values

O estudo da condução neural dos segmentos mais distais dos nervos mais longos pode ser capaz de reconhecer mais precocemente as alterações oriundas da maioria das polineuropatias. O objetivo deste estudo, foi verificar a aplicabilidade técnica do exame de condução ortodrômica do ramo cutâneo dorsal do nervo sural (nervo cutâneo dorsal lateral) em pessoas saudáveis, padronizar os valores normais para serem utilizados como referência e comparar seus valores com os do nervo sural na perna. Quarenta e cinco pessoas com idade média de 41,56 anos (19-75) foram avaliadas, com registro de potenciais de ação de nervo sensitivo nos noventa pés. O eletrodo de captação foi colocado inferior e posteriormente ao maléolo lateral e a estimulação realizada 10 cm distalmente na face dorso-lateral dos pés. O valor médio para a velocidade de condução do nervo sural cutâneo dorsal encontrado foi 47,35 +/- 4,8 m/s e para a amplitude, 4,19 +/- 1,9 mV. A velocidade de condução do segmento distal foi 14 por cento inferior à do proximal. A amplitude média dos potenciais de ação sensitivos do segmento distal foi 73 por cento aquém daquela obtida no segmento proximal. Os resultados confirmam a possibilidade técnica de se estudar o ramo cutâneo dorsal do nervo sural e sugerem que o limite mínimo de normalidade para sua velocidade de condução, após correção para a temperatura de 34§C, seja 38 m/s. Diferenças na amplitude e velocidade de condução devem ser consideradas entre grupos etários.

Las variaciones de la velocidad de conducción nerviosa en función de la temperatura no dependen de la edad / Temperature related nerve conduction velocity is not age-dependent

En 14 sujetos normales (edad x =48,1 ñ 23,9 años, rango 9-83) se estudiaron las variaciones de la velocidad de conducción del nervio sural (VC) en relación con las variaciones de la temperatura. Se analizaron los valores individuales de Q10 y b en función de la edad y no mostraron correlación (r - 0,31 y 0, 25, respectivamente). En el grupo de sujetos jóvenes (n = 7, edad x = 26,7 ñ 10,6 años, rango 9-47) se obtuvieron los valores Q10 - 1,36 y b 1,21 m/s/-C y en el grupo de sujetos de edad avanzada (n = 7, edad x = 72,0 ñ 8,9 años, rango 60-83) Q10 = 1,36 y b = 1,32 m/s/-C, valores similares al total de la muestra. En conclusión, las variaciones de la VC en función de la temperatura no dependen de la edad