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Maternal deprivation, as a result of the artificial rearing (AR) paradigm, disturbs electrophysiological and histological characteristics of the peripheral sensory sural (SU) nerve of infant and adult male rats. Such changes are prevented by providing tactile or social stimulation during isolation. AR also affects the female rat's brain and behavior; however, it is unknown whether this early adverse experience also alters their SU nerve development or if tactile stimulation might prevent these possible developmental effects. To assess these possibilities, the electrophysiological and histological characteristics of the SU nerve from adult diestrus AR female rats that: (i) received no tactile stimulation (AR group), (ii) received tactile stimulation in the anogenital and body area (AR-Tactile group), or (iii) were mother reared (MR group) were determined. We found that the amplitude, but not the area, of the evoked compound action potential response in SU nerves of AR rats was lower than those of SU nerves of MR female rats. Tactile stimulation prevented these effects. Additionally, we found a reduction in the outer diameter and myelin thickness of axons, as well as a large proportion of axons with low myelin thickness in nerves of AR rats compared to the nerves of the MR and AR-Tactile groups of rats; however, tactile stimulation only partially prevented these effects. Our data indicate that maternal deprivation disturbs the development of sensory SU nerves in female rats, whereas tactile stimulation partially prevents the changes generated by AR. Considering that our previous studies have shown more severe effects of AR on male SU nerve development, we suggest that sex-associated factors may be involved in these processes.

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To investigate variations regarding the formation and course of the sural nerve (SN). We dissected 60 formalin-fixed Brazilian fetuses (n = 120 lower limbs) aged from the 16th to 34th weeks of gestational age. Three incisions were made in the leg to expose the SN, and the gastrocnemius muscle was retracted to investigate the SN course. Statistical analyses regarding laterality and sex were performed using the Chi-square test. Eight SN formation patterns were classified after analysis. Type 4 (in which the SN is formed by the union of the MSCN with the LSCN) was the most common SN formation pattern. Although there was no statistical association between the formation patterns and the lower limb laterality (p = 0.9725), there was as to sex (p = 0.03973), indicating an association between anatomical variation and sex. The site of branch joining was in the distal leg most time (53.75%). In all lower limbs, the SN or its branches crossed from the medial aspect of the leg to the lateral margin of the calcaneal tendon (CT). Most often, the SN is formed by joining the MSCN and the LSCN in the distal leg. The SN or its branches ran close to the saphenous vein, crossed the CT from medial to lateral, and distributed around the lateral malleolus.

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Demonstration of the possibility to obtain the sensory nerve action potential (SNAP) of sural nerve in patients over 60 years old, without peripheral neuropathy. Prospective study on 101 patients older than 60 years of age. Stimulation was applied 12 cm proximal to the recording point. Two hundred and two SNAPs of the sural nerve were collected with an average peak latency of 3.2 ms, onset latency of 2.6 ms, peak-to-peak amplitude of 15.2 µV and velocity of 45.7 m/s. It was possible to obtain the sural nerve SNAP in all tested patients older than 60, without peripheral neuropathy. The values obtained in this study prove to be useful as a reference in the evaluation of patients older than 60 years of age.

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Despite the frequent clinical hyper- or hypothermia cases, thermal-dependence of the endogenous pain modulation system at the spinal cord is not well understood. We evaluate spinal dorsal horn neuronal network responses during mechanical heterotopic noxious stimuli (HNS) at three different body temperatures (34; 37 or 40°C) by measuring lumbar cord dorsum potentials activated by electrical stimulation of the ipsilateral sural nerve in adult thiopental anesthetized rats. A noxious clamp was applied randomly to the tail, right hindpaw, right forepaw, muzzle and left forepaw. HNS induced a decrease of the N wave amplitude and duration at 37°C. This effect was reduced at 40°C for both amplitude (-18.2% for 37-40°C; P<0.0005) and duration (-16.4% for 37-40°C; P<0.0001). P wave did not show neither amplitude nor duration changes at neither 3 tested temperatures. Clinical range changes of temperature could modify pain sensation, moreover, hyperthermia increases nociceptive sensory input to dorsal horn, and could exacerbate pain sensation in individuals with fever.

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Most of the endogenous pain modulation (EPM) involves the spinal dorsal horn (SDH). EPM including diffuse noxious inhibitory controls have been extensively described in oligoneuronal electrophysiological recordings but less attention had been paid to responses of the SDH neuronal population to heterotopic noxious stimulation (HNS). Spinal somatosensory-evoked potentials (SEP) offer the possibility to evaluate the neuronal network behavior, reflecting the incoming afferent volleys along the entry root, SDH interneuron activities and the primary afferent depolarization. SEP from de lumbar cord dorsum were evaluated during mechanical heterotopic noxious stimuli. Sprague-Dawley rats (n = 12) were Laminectomized (T10-L3). The sural nerve of the left hind paw was electrically stimulated (5 mA, 0.5 ms, 0.05 Hz) to induce lumbar SEP. The HNS (mechanic clamp) was applied sequentially to the tail, right hind paw, right forepaw, muzzle and left forepaw during sural stimulation. N wave amplitude decreases (-16.6 %) compared to control conditions when HNS was applied to all areas of stimulation. This effect was more intense for muzzle stimulation (-23.5 %). N wave duration also decreased by -23.6 %. HNS did not change neither the amplitude nor the duration of the P wave but dramatically increases the dispersion of these two parameters. The results of the present study strongly suggest that a HNS applied to different parts of the body is able to reduce the integrated electrical response of the SDH, suggesting that not only wide dynamic range neurons but many others in the SDH are modulated by the EPM.

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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 3.6 ms (0.4 SD), amplitude 6.1 mV (2.0 SD) and conduction velocity 54.8m/s (4.2 SD). Average tibial nerve distal latency was 3.5 ms (0.4 SD), amplitude 16.7mV (4.7 SD) and conduction velocity 53 m/s (3.8 SD). Average sural nerve peak latency was 3.4 ms (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 0.4 ms (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.

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OBJECTIVE: To assess whether sensorimotor peripheral nerve function is associated with muscle power in community-dwelling older men. DESIGN: Longitudinal cohort study with 2.3±0.3 years of follow-up. SETTING: One clinical site. PARTICIPANTS: Participants (n=372; mean age ± SD, 77.2±5.1y; 99.5% white; body mass index, 27.9±3.7kg/m(2); power, 1.88±0.6W/kg) at 1 site of the Osteoporotic Fractures in Men Study (N=5994). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: A nerve function ancillary study was performed 4.6±0.4 years after baseline. Muscle power was measured using a power rig. Peroneal motor nerve conduction amplitude, distal motor latency, and mean f-wave latency were measured. Sensory nerve function was assessed using 10-g and 1.4-g monofilaments and sural sensory nerve conduction amplitude and distal latency. Peripheral neuropathy symptoms at the leg and feet were assessed by self-report. RESULTS: After adjustments for age, height, and total body lean and fat mass, 1 SD lower motor (ß=-.07, P<.05) and sensory amplitude (ß=-.09, P<.05) and 1.4-g (ß=-.11, P<.05) and 10-g monofilament insensitivity (ß=-.17, P<.05) were associated with lower muscle power/kg. Compared with the effect of age on muscle power (ß per year, -.05; P<.001), this was equivalent to aging 1.4 years for motor amplitude, 1.8 years for sensory amplitude, 2.2 years for 1.4-g monofilament detection, and 3.4 years for 10-g detection. Baseline 1.4-g monofilament detection predicted a greater decline in muscle power/kg. Short-term change in nerve function was not associated with concurrent short-term change in muscle power/kg. CONCLUSIONS: Worse sensory and motor nerve function were associated with lower muscle power/kg and are likely important for impaired muscle function in older men. Monofilament sensitivity was associated with a greater decline in muscle power/kg, and screening may identify an early risk for muscle function decline in late life, which has implications for disability.

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The aim of this study was to determine the effect of chronic undernourishment on the amplitude depression of the first negative component in the cord dorsum potentials (N(1)-CDPs) caused by the conditioning stimulation of sensory cutaneous nerves in the rat spinal cord. Single electrical pulses (1Hz; 2 times threshold) applied to the sural (SU) nerve of control rats (n=14) produced CDPs with a first negative component (N(1)-CDPs) larger in amplitude (14.2±1.3%, p<0.01) than those recorded in chronically undernourished rats (n=14; 3 times threshold). The conditioning stimulation of the SP nerve (4 shocks at 300Hz, 3×T) in the control rats (n=5) evoked a long-lasting (~200ms) depression of the N(1)-CDP (60.2±7.2%). In contrast such depression was smaller in magnitude (42.5±5.7%, p<0.01) and time course (100-120ms) in undernourished rats (n=7). The systemic application of picrotoxin (PTX) reduced, but did not abolish the conditioned depression of the N(1)-CDPs and DRPs in both the control and undernourished rats. By assuming that the depression of the N(1)-CDPs is representative of presynaptic mechanisms, it is proposed that chronic undernourishment influence the activation of presynaptic neuronal pathways that regulate the transmitter release of cutaneous afferent fibers in the spinal cord and such effect could act as a compensatory mechanism that counterbalances the decreased activation of spinal neurons by the reduced afferent input in the rat.

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Pain is a subjective and individual sensation causing major discomfort. So, it is necessary to put into practice methods to objectively quantify it. Several studies indicate that evoked potentials (EP) generate responses which may reflect painful processes. This study reports the results of the application of two different protocols by using biopotentials to objectively measure pain. The first (protocol 1) evaluates the relation between pain, induced by electrical stimulation, and subjective perception and also with nociceptive flexion reflex (NFR) represented by muscle activity (electromyography) detected on the femoral biceps after sural nerve stimulation. The second protocol (protocol 2) verifies whether there is some correlation between M-wave parameters and subjective pain sensation. The results obtained from protocol 1 suggest that the area of the EMG envelope and entropy estimated from the EMG activity are correlated with subjective sensation of pain. The analysis of data obtained from protocol 2 shows a correlation between the global minimum of the M-wave and pain increase. These results contribute to studies which seek to objective measures for pain quantification based on the analysis of biopotentials.

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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.

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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.

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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.

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BACKGROUND: Using grafts directed to distal targets in brachial plexus reconstruction has the advantage over proximal targets of avoiding axonal dispersion. A long graft (more than 10 cm) is needed to reach most distal targets. The objective of this article is to identify factors associated with good versus poor outcomes in a clinical series of long grafts used for distal brachial plexus reconstruction. METHODS: In 34 patients with a flail arm, 47 sural grafts >10 cm long were followed for ≥2 years postoperatively. Surgical technique included standard supraclavicular exposure of the proximal brachial plexus and its branches, the phrenic nerve and spinal accessory nerve. Distal target nerves were exposed via an incision starting at the axilla, following the gap between the biceps and triceps. Cases achieving a good result were statistically compared against those with a poor result as to the donor nerve/root, target nerve, patient age and weight, time from trauma to surgery, graft length and long-term rehabilitation quality. FINDINGS: A good outcome was observed with 23 grafts (48.9%), but 66.7% of the 30 long grafts done within 6 months of trauma yielded a good result. Only 1 of 15 patients with the lowest quality rehabilitation score experienced a good result (6.6%) versus all 12 patients with the highest rating (p < 0.001). Trauma-to-surgery time was roughly half as long in those with a good result (4.7 vs. 9.0 months, p < 0.001). No other inter-group differences were observed. CONCLUSIONS: The results of a series of distal brachial plexus target reinnervations with long grafts is presented and analyzed. According to them, time from trauma to surgery and an adequate postoperative rehabilitation are important predictors of outcome.

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The effect of chronic undernourishment on the cord dorsum potentials (CDPs) and the dorsal root potential (DRP), closely related to primary afferent depolarization (PAD) and presynaptic inhibition in the spinal cord of the rat, was analyzed in this study. Single electrical pulses applied to the sural nerve (SU) of control (n=14) and chronically undernourished (n=16) Wistar rats produced CDPs, which are composed of four components: afferent volley (AV), two negative components (N(1) and N(2)), and one positive component (P wave) and negative DRPs recorded in a small rootlet of the L6 segment of the rat. The CDPs of the control and undernourished rats with AV components of comparable amplitude (U(AV)/C(AV)=0.96), showed N(1) components of similar amplitude (U(N1)/C(N1)=0.94), but smaller P wave (U(PW)/C(PW)=0.23). A comparable reduction in the amplitude of the DRPs was obtained in the undernourished rats (U(DRP)/C(DRP)=0.36). When normalized as a function of the body mass of the animals, the CDPs and DRPs produced in undernourished rats were of significantly smaller normalized amplitude than those evoked in the control. According to these results, it is suggested that chronic undernourishment induce a depressive effect on the mechanisms generating the P wave component in the CDP and the DRPs either by decreasing the sensory input and/or the excitability of the dorsal horn neurones involved in the generation of PAD and presynaptic inhibition in the spinal cord of the rat.

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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%) 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.

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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.

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UNLABELLED: The reliability of medial plantar, sural, and superficial peroneal nerve conduction studies (NCS) has not been widely studied. These nerves are usually involved in distal sensory neuropathies and their serial study is relevant in the clinical setting. PURPOSE: To determine the inter- and intrarater reliability of superficial peroneal, sural, and medial plantar NCS in healthy participants. METHODS: Two raters performed the bilateral NCS twice in 20 healthy participants (23.5 +/- 3.5 years). Reliability was analyzed by the Bland-Altman method and intraclass correlation coefficient (ICC). Variability was established by the coefficient of variation. RESULTS: The Bland-Altman method showed a good level of intra- and interrater agreement for all nerves. The amplitude (rater 1) and latency of the medial plantar nerve and the amplitude of the sural nerve (rater 2) had an intrarater ICC of >or=0.75. Interrater analysis showed concordance levels between moderate and very low. The highest coefficients of variations were found for amplitude and the lowest for nerve conduction velocity. CONCLUSIONS: Although the Bland-Altman method confirmed a good intra- and interrater reliability of the studied nerves, ICC analyses showed mixed results. These statistical approaches are complementary, and each one has advantages and disadvantages that must be considered in their application and interpretation.

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INTRODUCTION: There are various options for covering soft tissue defects in the lower extremities, but the distal third of the leg continues to be a difficult area. The distally-based sural neurocutaneous flap which is based on the sural nerve and the superficial sural artery has been an important option since it was first proposed. METHODS AND MATERIALS: 16 children, with an average age of 9 years had different local lesions on the distal third of the leg or foot which compromised the Achilles tendon, extensor tendons in the foot and toes or the osteoarticular system, were treated using the distally-based sural flap. One patient had an amputation at midfoot caused by a garden strimmer, seven had lesions caused by motorcycle accidents and eight were caused by car accidents. RESULTS: The minimum follow up was 8 months. In all cases, the lesions were successfully covered. Only one showed necrosis of the flap, but the adipofascial tissue was well irrigated and was resurfaced by a free skin graft. CONCLUSION: The distally-based sural neurocutaneous flap is a good alternative for soft tissue defects in the distal area of the leg, a region where it is historically difficult to cover soft tissue defects.

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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.

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The aim of this study was to analyze the possible alterations produced by inadequate perinatal food intake, in quantity (undernutrition) or quality (malnutrition), on the generation and propagation of the compound action potential (CAP) evoked in sensory sural nerves, during the postnatal development of the rat. Low intensity stimulation (2-3 times the threshold of the most excitable nerve fibers; xT) of the sural nerve evoked an early potential (CAP-A component) which is due to activation of low-threshold, fast-conducting myelinated group A afferent fibers. Meanwhile, at higher stimulus intensity (20-30T) it produced a second, long-lasting potential (CAP-C component) probably due to activation of high-threshold, slow-conducting group Adelta or C afferent fibers. Compared to control nerves, the CAP-A component, but not the CAP-C component of undernourished and malnourished nerves showed significant changes in amplitude, area, electrical threshold and conduction velocity (except absolute refractory period) at several postnatal ages. Our results may suggest that a relative large number of myelinated group A afferent fibers in the sural nerve of undernourished and malnourished animals suffer severe alterations on their electrophysiological properties of generation and propagation of the action potential during the postnatal development of the rat.

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