Sural nerve conduction: Amplitude and distal latency of sensory nerve action potential

Background: The sensory nerve action potential (SNAP) is an important factor in the electro diagnostic evaluation of a patient with suspected peripheral neuropathy. Sural nerve is the most frequently studied nerve in the electrophysiology. For proper diagnosis sural sensory conduction abnormalities, a reference data are required for each electrophysiology laboratory. Aims and Objectives: The aim of the study was to find out normative reference data of amplitude and distal latency (DL) of sural SNAP for Northern Kerala population. Materials and Methods: The study was designed as cross-sectional and observational study and analysis of values was done using SPSS version 16. A total of 250 healthy subjects of age 15–50 from Northern Kerala participated in the study which included equal number of males and females. Results: Normative reference data for sensory amplitude and DL were derived in the present study. Sensory amplitude was more and DL was found to be less in female population, indicating faster nerve conduction in female. Conclusion: The reference data derived here can be utilized to detect any abnormality sural nerve sensory conduction. The gender effect on sural nerve sensory conduction parameters can be attributed to the height difference, as nerve conduction velocity is inversely proportional to height.

Clinical analysis of chronic mild occupational carbon disulfide poisoning / 中国职业医学

Objective: To analyze clinical features and electroneuromyography (ENMG) results of chronic mild occupational carbon disulfide poisoning cases. Methods: A total of 344 patients diagnosed with chronic mild occupational carbon disulfide poisoning based on GBZ 4-2002 Diagnostic Criteria of Occupational Chronic Carbon Disulfide Poisoning were selected as study subjects from 2006 to 2019 using the retrospective study method. Their clinical data was collected and analyzed. Results: The main symptoms of the study subjects were dizziness, headache, insomnia, dreaming, memory impairment, numbness and weakness in the distal extremities. Positive signs mainly included symmetrical glove and stocking distribution like sensory disorders in the distal extremities, and the weakening or absent Achilles tendon reflex and knee reflex. The incidence of symptoms and signs increased with the length of service (all P<0.01). The incidence of fundus and venous changes in patients was 41.3%, which increased with the length of service (P<0.01). ENMG examination showed varying degrees of abnormalities in the peripheral motor and/or sensory nerves in all patients, with a higher incidence of motor nerve abnormalities than sensory nerve abnormalities (21.1% vs 3.7%, P<0.01). The incidence of motor nerve abnormality was higher on the right side than the left side (23.7% vs 18.5%, P<0.01). The incidences of motor nerve abnormalities from high to low in the order were median nerve, common peroneal nerve, ulnar nerve and posterior tibial nerve (34.9% vs 27.9% vs 16.6% vs 5.1%, P<0.01). The incidences of sensory nerve abnormalities from high to low in the order were median nerve, ulnar nerve and sural nerve (5.2% vs 5.1% vs 0.7%, P<0.01). The incidences of left ulnar nerve, right ulnar nerve and right median nerve were higher in male patients than in female patients (15.2% vs 5.3%, 24.0% vs 11.7%, 44.8% vs 28.7%, all P<0.05), while the incidences of the left and right common peroneal nerve in lower extremity motor nerve were lower in male patients than in female patients (18.4% vs 52.1%, 21.2% vs 46.8%, all P<0.01). Conclusion: Chronic mild occupational carbon disulfide poisoning was mainly manifested as multiple peripheral nerve injury. ENMG results showed that the distal motor nerve conduction abnormalities were more sensitive than the sensory nerve conduction abnormalities, with a higher degree of impairment in the upper limb than the lower limb, and more impairment in the right side than the left side.

Nerve Conduction Studies in Asymptomatic HIV Positive Persons

Background: Nerve Conduction Studies were performed in asymptomatic HIV positive persons and corresponding controls to detect subclinical peripheral nervous system involvement in early stage of HIV. Aims & Objective: To perform Nerve Conduction Studies in asymptomatic HIV positive persons and corresponding controls. Material and Methods: In this study,100 participants in the age group 25-45 years were selected. In study group, 50 3 participants who were HIV positive and asymptomatic (CD4 count > 350 cells/mm ) and were not on Anti Retro Viral Treatment (ART), were included. In control group 50 healthy age matched HIV negative participants were included. We performed Nerve Conduction Studies in these participants. For motor nerves, Distal Latency (DL), Motor Nerve Conduction Velocity (MNCV), Compound Muscle Action Potential (CMAP) amplitude were measured and for sensory nerves Onset Latency (OL), Sensory Nerve Conduction Velocity (SNCV) and Sensory Nerve Action Potential (SNAP) amplitude were measured. Results: Nerve Conduction Studies in asymptomatic HIV revealed that, MNCV was significantly decreased for median motor nerve and tibial motor nerve in study group compared to control group, SNAP was significantly reduced for median sensory nerve in study group compared to control group, OL was significantly prolonged for sural nerve in study group than control group and SNCV was significantly decreased for sural nerve in study group than control group. Conclusion: Nerve Conduction Studies in asymptomatic HIV positive persons suggests subclinical peripheral nervous system involvement in early stages of HIV. Hence Nerve Conduction Studies can be important to detect subclinical peripheral nervous system involvement in the early stages of HIV.

Localization of the lateral cutaneous branch of subcostal nerve in iliac crest region and its application in the free sensory superficial circumflex iliac artery perforator flap / 中华显微外科杂志

Objective:To analyze the feasibility of applying transcutaneous electrical nerve stimulator and high-frequency ultrasound in superficial nerve positioning for detection anatomical location in the area of lateral lip of the iliac crest by lateral cutaneous branch of subcostal nerve(LCSN). The significance of using the nerve as a free sensory superficial circumflex iliac artery perforator flap was discussed.Methods:The data of patients who underwent the repair of defects on limbs with free perforator flap or composite flap of superficial iliac circumflex artery carrying sensory nerve and the volunteers who agreed to have the location of the LCSN measured between October, 2018 and October, 2020 were collected. The LCSN were located by percutaneous electrical nerve stimulation and ultrasound, and the patients were measured and located during surgery. Using Passing-Bablok regression and Bland-Altman graph to evaluated the consistency between transcutaneous electrical nerve stimulation, ultrasound and the surgical positioning.Results:A total of 43 subjects, including 22 patients and 21 volunteers, were selected for locating the LCSN. Thirty-nine males and 4 females, with an average age of 39 years old and an average BMI of 24.08. The operation time of percutaneous nerve electrical stimulation was(6±1) min, and the detection distance was(80.7±5.9) mm. The high-frequency ultrasound was(23±4) min, and the distance was(81.2± 6.6) mm. The average operation time of surgical measured distance was(80.9±8.2)(65-100) mm, the diameter of nerve was(2.3±0.8)(1.0-4.0) mm, and the operation time was(5±1) min. A 95% CI of Passing-Bablok regression intercept and slope of operation, percutaneous electrical nerve stimulation and ultrasoundincluded 0 and 1, respectively. The points on Bland-Altman plot were distributed on both sides, and 95% CI of total mean difference, total intercept and slope included 0. Therefore, it was can be considered that the application of percutaneous electrical nerve stimulation and ultrasound in LCSN localization has good consistency.Conclusion:The location point of the LCSN crossing the iliac crest which detected by transcutaneous electrical nerve stimulation and high-frequency ultrasound detection was close to the measurement taken during the operation. It was also showed that both of them can be used for preoperative locationing of the sensory branch of the sensory nerve flap, optimizing the design of the flap, shortening the operation time, and reducing the unnecessary injury in operation.

A comparative study of the conduction velocity of motor and sensory fibres of ulnar and median nerves among leprosy patients and normal subjects

Background: Leprosy and the associated scourge have affected humanity for thousands of years. One of the most debilitating consequences of leprosy is peripheral neuropathy. Nerve Conduction Velocity study provides us with a non-invasive modality to assess peripheral nerve involvement in leprosy.Methods: With this in mind, a cross-sectional observational study was conducted including 30 leprosy patients as "Cases" and 30 age-matched healthy subjects, not suffering from any kind of neurological disorders, as "Controls". Using a digital electromyography machine, the Latency, Amplitude and Conduction Velocities of Motor and Sensory fibres of Ulnar and Median nerves were recorded. The results were compared among controls and cases using suitable statistical tests (descriptive statistics and significance testing using unpaired t-test).Results: In this study, with regard to Sensory Nerve conduction Velocity (SNCV), statistically very significant difference was noted in case of right (p 0.0011) and left (p 0.0037) ulnar nerves among controls and cases. The difference in the amplitude of Motor Action potential (MAP) with regard to right median nerve, among cases and controls, was also statistically significant (p 0.0127). Further the amplitude of Sensory Nerve Action Potential (SNAP) values were higher among cases compared to controls.Conclusions: As such, the findings of this study (and which is also corroborated by many previous studies) lead us to the conclusion that NCV studies can detect lepromatous neuropathy much before the emergence of frank clinical signs and this type of neuropathy is predominantly demyelinating in nature with occasional axonal loss.

Characteristics of peripheral nerve damage caused by occupational acute trimethyltin chloride poisoning / 中国职业医学

OBJECTIVE: To explore the characteristics of peripheral nerve injury caused by occupational acute trimethyltin chloride(TMT) poisoning. METHODS: The clinical manifestations and test data of neurotic electrophysiology, pure tone hearing threshold and acoustic immittance in 16 patients with occupational acute TMT poisoning were retrospectively analyzed. The patients were followed up after 6 months of discharge. RESULTS: Among the 16 cases of occupational acute TMT poisoning, 6, 4 and 6 cases were with mild, moderate and severe poisoning, respectively. For the firstly appeared symptoms, 7 cases had abnormal mental behavior and memory loss, 5 cases had tinnitus and hearing loss, 5 cases had decreased visual acuity, 2 cases had diplopia and 2 cases had binocular pain. The main clinical manifestations included 8 cases of disturbance of consciousness, and 6 cases of abnormal orientation and aggressive behavior. After correction of hypokalemia, 7 cases of patients had limb muscle weakness, hypomyotonia and weakened tendinous reflect, 9 cases had decreased tactile sensation below the groin in the lower limbs, and 6 cases had instability of walking. The main manifestations of neuroelectrophysiological detection were: 9 patients(accounting for 56.3%) showed abnormal neuroelectromyography, 4 cases of severe poisoning had damaged motor nerve, sensory nerve axon and myelin sheath, and the proximal nerve was also partially damaged. There were 2 cases of moderate poisoning showing abnormal symptoms, the axon and myelin sheath of sensory nerve were damaged, one common peroneal nerve was demyelinated. Three cases of mild poisoning had one common peroneal nerve axon damaged, one proximal tibial nerve damaged, and the axon and myelin sheath of sensory nerve were damaged. Brainstem auditory evoked potential I wave and visual evoked potential P100 latency prolonged and amplitude decreased in some of the patients with mild, moderate and severe poisoning. The sensorineural hearing loss occurred in 81.3% of patients. CONCLUSION: Occupational acute TMT poisoning can cause damage to motor nerve, sensory nerve axon and myelin sheath of extremities. Both distal and proximal nerves might be involved. It can also damage cochlear hair cells and optic nerve. Attention should be paid to the early treatment of peripheral nerve damage, cochlear hair cell and optic nerve damage caused by TMT.

Effect of red light combined with hot compress on peripheral neuropathy of diabetes / 中国基层医药

Objective@#To investigate the effect of red light combined with hot compress on diabetic peripheral neuropathy (DPN).@*Methods@#From June 2017 to June 2018, 110 patients with DPN admitted to the Department of Endocrinology, Hangzhou Hospital of Traditional Chinese Medicine were selected in the study.The patients were divided into study group (55 cases) and control group (55 cases) according to the random number table method.All patients were given DPN basic care and treatment, with red light in the control group, and red light combined with hot compress in the study group.The motor nerve conduction velocity (MCV) and the sensory nerve conduction velocity (SCV) of the ulnar nerve, median nerve and common peroneal nerve were compared between the two groups before and after treatment.The total scores of the Toronto clinical scoring system (TCSS) were compared between the two groups before and after treatment.The efficacy of the two groups was compared.@*Results@#Before treatment, there were no statistically significant differences in MCV [(40.45±5.33)m/s vs.(40.14±5.08)m/s, t=0.312, P=0.755; (41.15±5.51)m/s vs.(40.86±5.23)m/s, t=0.283, P=0.778; (42.27±5.84)m/s vs.(41.94±5.75)m/s, t=0.299, P=0.766] and SCV [(39.38±4.82)m/s vs.(39.08±4.60)m/s, t=0.334, P=0.739; (40.13±5.45)m/s vs.(39.86±5.15)m/s, t=0.267, P=0.790; (41.18±5.78)m/s vs.(40.89±5.46)m/s, t=0.278, P=0.782] between the ulnar nerve, median nerve and common peroneal nerve in the two groups.After treatment, the ulnar nerve, median nerve and common peroneal nerve of the two groups were treated.The MCV[(48.77±7.25)m/s vs.(44.62±6.30)m/s, t=3.204, P=0.002; (49.35±7.46)m/s vs.(45.36±6.45)m/s, t=3.001, P=0.003; (49.26±7.13)m/s vs.(46.35±6.22)m/s, t=2.281, P=0.025] and SCV[(47.67±6.52)m/s vs.(43.57±5.61)m/s, t=3.535, P=0.001; (47.77±6.63)m/s vs.(44.31±5.14)m/s, t=3.059, P=0.003; (48.33±7.17)m/s vs.(45.12±6.41)m/s, t=2.475, P=0.015] of the two groups were increased, while which of the study group increased more significantly.Before treatment, there was no statistically significant difference in the total scores of TCSS between the two groups [(10.15±1.23)points vs.(10.45±1.51)points, t=1.142, P=0.256]. After treatment, the total scores of TCSS decreased in the two groups, while which of the study group decreased more significantly[(7.22±0.85)points vs.(8.15±0.96)points, t=5.379, P=0.000]. After treatment, the effective rate of the study group was 87.27%, which of the control group was 63.64%, the difference was statistically significant(χ2=8.295, P=0.004).@*Conclusion@#The combination of red light and hot compress on DPN has a more prominent clinical effect, which is worthy of wide application.

Ultrasound-guided lumbar sympathetic block for flap repair of lower limb defects / 中华创伤骨科杂志

Objective To evaluate the efficacy of ultrasound-guided lumbar sympathetic block (LSB) used for flap repair of lower limb defects.Methods A retrospective study was conducted of the 27 patients who had received flap repair of lower limb defects at Department of Anesthesiology,Central People's Hospital of Zhanjiang surgery from June 2017 to December 2018.Of them,14 had conventional flap repair (conventional group) and 13 additional ultrasound-guided LSB (LSB group).The 2 groups were compared at 12,24,48 and 72 hours after operation in terms of color,texture,skin temperature and survival of the flaps and visual analogue scale (VAS) pain scores.Functional recovery of flap sensation after one month follow-up was also observed and compared.Results The 2 groups were comparable because there were no significant differences between them in the preoperative general data(P ＞ 0.05).All the patients were followed up for an average of 3.1 months (from 2 to 6 months).At 12 and 24 hours after operation,the LSB group had significantly more patients with normal flap color (84.6％ and 92.3％) than the conventional group (35.7％ and 50.0％) (P ＜ 0.05).At 12,24,48 and 72 hours after operation,the LSB group had significantly higher skin temperature (36.7 ± 0.2 ℃,36.8±0.3 ℃,36.9±0.2 ℃ and 36.9±0.1 ℃) than the conventional group(35.4±0.4 ℃,35.7 ± 0.6 ℃,35.9 ± 0.3 ℃ and 36.2 ± 0.2 ℃) (P ＜ 0.05).At 12 and 24 hours after operation,the LSB group had significantly lower VAS pain scores (2.1 ± 1.0 and 2.3 ± 0.9) than the conventional group(4.6 ± 0.9 and 4.4 ±0.8) (P ＜0.05).All the flaps in the LSB group obtained primary survival after operation while infection occurred in one case in the conventional group.One month follow-up showed that 12 patients in the LSB group (92.3％) obtained sensory recovery of flaps while 6 ones (42.9％) did in the conventional group,showing a significant difference (P ＜ 0.05).Conclusion As an auxiliary treatment for flap repair of lower limb defects,SLB can improve the blood supply to the transplanted flap and facilitate the recovery of nerve function in the graft flap.

Effect of red light combined with hot compress on peripheral neuropathy of diabetes / 中国基层医药

Objective To investigate the effect of red light combined with hot compress on diabetic peripheral neuropathy (DPN).Methods From June 2017 to June 2018,110 patients with DPN admitted to the Department of Endocrinology,Hangzhou Hospital of Traditional Chinese Medicine were selected in the study. The patients were divided into study group (55 cases) and control group (55 cases) according to the random number table method.All patients were given DPN basic care and treatment,with red light in the control group,and red light combined with hot compress in the study group.The motor nerve conduction velocity ( MCV) and the sensory nerve conduction velocity (SCV) of the ulnar nerve,median nerve and common peroneal nerve were compared between the two groups before and after treatment.The total scores of the Toronto clinical scoring system ( TCSS) were compared between the two groups before and after treatment.The efficacy of the two groups was compared.Results Before treatment,there were no statistically significant differences in MCV [(40.45 ± 5.33)m/s vs.(40.14 ± 5.08)m/s,t=0.312,P=0.755;(41.15 ± 5.51)m/s vs.(40.86 ± 5.23)m/s,t=0.283,P=0.778;(42.27 ± 5.84)m/s vs.(41.94 ± 5.75)m/s, t=0.299,P=0.766] and SCV [(39.38 ± 4.82) m/s vs.(39.08 ± 4.60) m/s,t=0.334,P=0.739;(40.13 ± 5.45)m/s vs.(39.86 ± 5.15)m/s,t=0.267,P=0.790;(41.18 ± 5.78)m/s vs.(40.89 ± 5.46) m/s,t=0.278, P=0.782] between the ulnar nerve,median nerve and common peroneal nerve in the two groups.After treatment,the ulnar nerve,median nerve and common peroneal nerve of the two groups were treated.The MCV[(48.77 ± 7.25)m/s vs.(44.62 ± 6.30)m/s,t=3.204,P=0.002;(49.35 ± 7.46)m/s vs.(45.36 ± 6.45)m/s,t=3.001,P=0.003;(49.26 ± 7.13)m/s vs.(46.35 ± 6.22)m/s,t=2.281,P=0.025] and SCV[(47.67 ± 6.52)m/s vs.(43.57 ± 5.61)m/s,t=3.535,P=0.001;(47.77 ± 6.63)m/s vs.(44.31 ± 5.14) m/s,t=3.059,P=0.003;(48.33 ± 7.17)m/s vs.(45.12 ± 6.41)m/s,t=2.475,P=0.015] of the two groups were increased,while which of the study group increased more significantly.Before treatment,there was no statistically significant difference in the total scores of TCSS between the two groups [(10.15 ± 1.23) points vs.(10.45 ± 1.51) points,t=1.142,P=0.256].After treatment,the total scores of TCSS decreased in the two groups, while which of the study group decreased more significantly[(7.22 ± 0.85)points vs.(8.15 ± 0.96)points,t=5.379,P=0.000].After treatment,the effective rate of the study group was 87.27%,which of the control group was 63.64%,the difference was statistically significant (χ2 =8.295,P=0.004).Conclusion The combination of red light and hot compress on DPN has a more prominent clinical effect,which is worthy of wide application.

Potencial de ação duplo e alterações ecográficas do nervo mediano em doentes com síndrome do túnel cárpico / Double peak action potential and ultrasonography nerve evaluation in patients with carpal tunnel syndrome

Introdução: A síndrome do túnel cárpico (STC) é sustentada pela presença de lentificação do potencial de ação do nervo mediano no estudo ortodrómico de condução nervosa sensitiva em comparação com o nervo radial (EC-MR). Uma técnica modificada de registo simultâneo de ambos os nervos (EC-MRsimul) pode ser utilizada, detetando a lentificação do nervo mediano através da presença de potencial de ação sensitivo duplo (PAS-D). O objetivo deste estudo é correlacionar o PAS-D com os achados de EC-MR e com o edema perineural em doentes com diagnóstico de STC. Métodos: Indivíduos saudáveis e doentes com STC há menos de 12 meses foram submetidos a avaliação eletrofisiológica, incluindo o EC-MR e o EC-MRsimul. Foi também realizada ultrassonografia para registo da área seccional do nervo mediano (AS-NM) no punho e antebraço e, respetivo índice punho-antebraço (I-PA). Resultados: Foram recrutados 38 doentes com idade média de 54,8 ± 15,3 anos com STC e 18 indivíduos saudáveis. A diferença de latência distal entre o nervo mediano e radial foi superior nos doentes (0,80 ± 0,30ms vs. 0,15 ± 0,20ms; p=0,015). O EC­MRsimul demonstrou a presença de PAS-D nos indivíduos sintomáticos. A AS­NM no punho foi também superior nos doentes (8,9 ± 0,9mm2 vs. 6,6 ± 0,7mm2; p<0.003), tendo sido identificado um quisto sinovial e um neurinoma. O edema perineural traduzido pela AS-SM correlacionou-se positivamente com a diferença de latência interpico no EC-MR e com a presença de PAS-D. Conclusão: O PAS-D está associado à presença de lentificação da condução e ao edema perineural do nervo mediano no contexto de STC ou devido a lesões ocupantes de espaço. (AU)

Introduction: Carpal tunnel syndrome (CTS) is characterized by median nerve action potential slowing, which can be shown in comparative orthodromic sensory nerve conduction studies between median and radial nerve (NCS-MR). A modified technique with simultaneous recording of both nerves (NCS-MRsimul) can also be used to detect median nerve slowing through the presence of double peak action potential (DPp). The study aims to correlate the presence of DPp with NCS-MR findings and with perineural edema in patients diagnosed with STC. Methods: Healthy individuals and patients with CTS for less than 12 months underwent NCS-MR and MRsimul. An ultrasonography evaluation was also performed to record the medial nerve sectional area (SA-MN) on the wrist and forearm, and the wrist-to-forearm ratio (WFR) was calculated. Results: We recruited 38 patients with CTS whose mean age was 54.8 ± 15.3 years and 18 healthy individuals. Distal latency difference between the median and radial nerves was higher in patients with CTS (0.80 ± 0.30 ms vs. 0.15 ± 0.20 ms, p = 0.015). NCS-MRsimul showed DPp in symptomatic individuals. SA-MN in the wrist was also higher in patients with CTS (8.9 ± 0.9 mm2 vs. 6.6 ± 0.7 mm2 , p <0.003). Ultrasonography evaluation identified a synovial cyst and a neurinoma. Perineural edema traduced by higher SA-MN and WFR correlated positively with interpeak latency difference in NCS-MR and with the presence of DPp. Conclusions: DPp was associated with median nerve sensory action potential slowing and with perineural edema due to either CTS or to space-occupying lesions. (AU)

Capsaicin-Sensitive Sensory Nerves Indirectly Modulate Motor Function of the Urinary Bladder / 대한배뇨장애요실금학회지

PURPOSE: The urinary bladder (UB) is innervated by both sensory and autonomic nerves. Recent studies have shown that sensory neuropeptides induced contractions in the detrusor muscle. Therefore, in a mouse model, we investigated the presence of interactions between the submucosal sensory nerves and the autonomic nerves that regulate the motor function of the detrusor muscle. METHODS: UB samples from male C57BL/6 mice were isolated, cut into strips, and mounted in an organ bath. Dose-response curves to norepinephrine and phenylephrine were studied in UB strips with and without mucosa, and the effects of preincubation with a receptor antagonist and various drugs on relaxation were also studied using tissue bath myography. RESULTS: Phenylephrine-induced relaxation of the UB strips showed concentration-related effects. This relaxation appeared in both mucosa-intact and mucosa-denuded UB strips, and was significantly inhibited by lidocaine, silodosin, and guanethidine (an adrenergic neuronal blocker). Meanwhile, phenylephrine-induced relaxation was inhibited by pretreatment with propranolol and calcitonin gene-related peptide (CGRP)–depletory capsaicin in UB strips with and without mucosa. CONCLUSIONS: The present study suggests that phenylephrine activates the α-1A adrenergic receptor (AR) of the sensory nerve, and then activates capsaicin-sensitive sensory nerves to release an unknown substance that facilitates the release of norepinephrine from adrenergic nerves. Subsequently, norepinephrine stimulates β-ARs in the detrusor muscle in mice, leading to neurogenic relaxation of the UB. Further animal and human studies are required to prove this concept and to validate its clinical usefulness.

Reference values for nerve conduction studies in healthy newborns, infants and children in Philippine Children's Medical Center

@#<p style="text-align: justify;"><strong>BACKGROUND:</strong> Nerve conduction studies play a diagnostic role in the clinical evaluation of neuromuscular disorders in children. Reference ranges define the expected parameter values in disease-free children.</p><p style="text-align: justify;"><strong>OBJECTIVE:</strong> To propose reference values for sensory and motor nerve conduction and late responses in upper and lower limb peripheral nerves in Filipino children 5 years and below.</p><p style="text-align: justify;"><strong>METHODS</strong>: Sensory nerve conduction studies on median, ulnar, superficial peroneal, and sural nerves and motor nerve conduction and late response studies on median, ulnar, peroneal and posterior tribal nerves were done using standardized techniques among 100 healthy Filipino children.</p><p style="text-align: justify;"><strong>RESULTS:</strong> Subjects were stratified according to age groups. Reference values for the following parameters: (1) sensory conduction velocity and amplitude; (2) motor conduction velocity, amplitude and latency at distal sites;  (3) F-wave latency; and (4) H-reflex latency were summarized. These were expressed as mean ±standard deviation or median (range) for values that follow Gaussian and non-Gaussian distributions. The 5th and 95th percentile values were likewise reported. Age had direct correlation with various nerve conduction parameters. Height was directly correlated with F-wave parameters of median, ulnar and peroneal nerves but not posterior tribal nerve.</p><p style="text-align: justify;"><strong>CONCLUSIONS</strong>: Reference standards for nerve conduction studies of commonly tested nerves of Filipino children are presented. Values are comparable to reference ranges elsewhere except for the H-reflex latency which is higher in this study.</p>

Usefulness of End-to-Side Bridging Anastomosis of Sural Nerve to Tibial Nerve: An Experimental Research

OBJECTIVE: Repair of sensorial nerve defect is an important issue on peripheric nerve surgery. The aim of the present study was to determine the effects of sensory-motor nerve bridging on the denervated dermatomal area, in rats with sensory nerve defects, using a neural cell adhesion molecule (NCAM). METHODS: We compared the efficacy of end-to-side (ETS) coaptation of the tibial nerve for sural nerve defect repair, in 32 Sprague-Dawley rats. Rats were assigned to 1 of 4 groups: group A was the sham operated group, group B rats had sural nerves sectioned and buried in neighboring muscles, group C experienced nerve sectioning and end-to-end (ETE) anastomosis, and group D had sural nerves sectioned and ETS anastomosis was performed using atibial nerve bridge. Neurological evaluation included the skin pinch test and histological evaluation was performed by assessing NCAM expression in nerve terminals. RESULTS: Rats in the denervated group yielded negative results for the skin pinch tests, while animals in the surgical intervention groups (group C and D) demonstrated positive results. As predicted, there were no positively stained skin specimens in the denervated group (group B); however, the surgery groups demonstrated significant staining. NCAM expression was also significantly higher in the surgery groups. However, the mean NCAM values were not significantly different between group C and group D. CONCLUSION: Previous research indicates that ETE nerve repair is the gold standard for peripheral nerve defect repair. However, ETS repair is an effective alternative method in cases of sensorial nerve defect when ETE repair is not possible.

Low amplitude dorsal ulnar cutaneous nerve sensory nerve action potential from cross over innervation. Can nerve ultrasound help?

The ulnar dorsal aspect of the hand is predominantly innervated by the dorsal ulnar cutaneous nerve with variable input from the superficial radial cutaneous nerve. This cross innervation can cause difficulty in interpreting low amplitude sensory nerve action potential for the dorsal ulnar cutaneous nerve particularly when facing suspected ulnar neuropathyat the elbow. In three subjects with low dorsal ulnar cutaneous sensory nerve action potential amplitude due to cross over with the superficial radial nerve, we compared amplitude with nerve circumference and fascicular count as measured by ultrasound. Dorsal ulnar cutaneous nerve circumference was significantly smaller where there was low sensory nerve action potential amplitude and showed fewer fascicles. Nerve ultrasonography may be a useful additional test modality to determine if low dorsal ulnar cutaneous nerve amplitude is physiological.

Experimental study on the effect of VIP on MVD in the process of fracture healing in rats with high selectiveneurotomy / 医学研究生学报

Objective The mechanism and signaling mechanisms of fracture healing by vasoactive intestinal peptide (VIP) regulating are not clear.We established an selective cut off sensory/motor nerve combined with tibial fracture rat model to study the effects of VIP and microvessel density(MVD) during the fracture healing process after nerve injury.Methods 60 SD rats were randomly divided into 3 groups: tibial fracture + motor nerve (anterior root) cutting group (group ART);tibial fracture + posterior root (sensory nerve) cutting group (group PRT);tibial fracture group (group SO),and each group were 20.Three groups of rats in the model after the establishment of 1W, 2W, 3W, 4W these time points, were killed.The skeleton specimens were obtained in the vicinity of the fracture 5mm, to observe the expression of VIP and microvessel density of the law of change.Results Histology observation showed: new bone trabecular bone callus maturity of PRT group is lower than SO group and ART group at each time points;the immunohistochemical staining showed that compared with callus VIP average optical density of PRT group at 2w and 3w(0.156±0.015、0.163±0.012), SO group(0.216±0.012、0.223±0.010) and ART group(0.198±0.014、0.212±0.016) increased obviously(P<0.05).The detection of callus MVD indicated that compared with callus MVD average density of PRT group at 2w and 3w(26.4±2.2、32.3±2.0), SO group(38.2±2.3、40.6±2.6) and ART group(36.6±2.2、38.5±2.1) significant increased (P<0.05).At the 2nd, 3rd and 4th week, the wet weight of tibia was significantly increased in group ART and SO compared with group PRT(P<0.05),which increased more significantly at 2 weeks.Conclusion The effect of loss of sensory nerve innervation on the formation of microvessel density, callus maturity and fracture healing rate were more pronounced than loss of motor nerve innervation.

Effect of selective sensory radicotomy before or after the ganglion on tibia fracture healing / 中华显微外科杂志

Objective To analyze the effect of the fracture healing by using selective sensory radicotomy before and after the ganglion.Methods From September,2014 to August,2015,120 rats were averagely divided into 3 groups,which was the sham operate group(SO),the anterior injury of ganglion rhizotomy group (AGR) and the posterior injury of ganglion rhizotomy group (PGR).Tibial transverse fracture was performed on right or left randomly and the fracture was fixed with intramedullary.In coordination with the fractured-side,the selective radicotomy from L4 to L6 was made.The mRNA level of collagen-Ⅰ and collagen-Ⅱ in bony callus was quantified at 3,7 days and 2 weeks after the operation by RT-PCR(n=5).The histological examination,X-ray,biomechanical testing were performed at 4 and 8 weeks.The quantitative data of iconography and biomechanics was acquired by using the relative ration which resulted from fractured-side data dividing the unfractured-side one for every pair tibia in same rat.Results At 3 days after surgery,the mRNA of collagen-Ⅰ were 81.3±11.1,37.5±8.2 and 24.7±9.2,the mRNA of collagen-Ⅱ were 2.4±0.5,2.1±1.0 and 2.9±1.2 in SO,AGR and PGR group respectively;At 7 days after surgery,the mRNA of collagen-Ⅰ were 17.9±5.8,7.2±1.8 and 6.7±2.4,the mRNA of collagen-Ⅱ were 12.5±3.4,2.8±1.3 and 1.2±0.4 in SO,AGR and PGR group respectively.The SO group had significantly upregulation of collagen-Ⅰ and collagen-Ⅱ mRNA compared with the AGR and PGR groups at 3 days and 7 days respectively after surgery(P＜0.05).There was a significant difference of the collagen-Ⅱ between AGR group (2.8±1.3) and PGR group (1.2±0.4) at 7 days after injury(P＜ 0.05).The fracture bony callus in PGR group was a significantly larger and less ossified than that in the AGR group.The mechanical load of fracture in SO group was larger than that of the other 2 groups (P＜0.05).Conclusion Sensory denervation negatively affects fracture-healing.The ganglion of sensory nerve plays an important role in bone fracture healing and normal innervation is essential for the fracture repair.

TRPV1 and TRPA1 in cutaneous neurogenic and chronic inflammation: pro-inflammatory response induced by their activation and their sensitization

Cutaneous neurogenic inflammation (CNI) is inflammation that is induced (or enhanced) in the skin by the release of neuropeptides from sensory nerve endings. Clinical manifestations are mainly sensory and vascular disorders such as pruritus and erythema. Transient receptor potential vanilloid 1 and ankyrin 1 (TRPV1 and TRPA1, respectively) are non-selective cation channels known to specifically participate in pain and CNI. Both TRPV1 and TRPA1 are co-expressed in a large subset of sensory nerves, where they integrate numerous noxious stimuli. It is now clear that the expression of both channels also extends far beyond the sensory nerves in the skin, occuring also in keratinocytes, mast cells, dendritic cells, and endothelial cells. In these non-neuronal cells, TRPV1 and TRPA1 also act as nociceptive sensors and potentiate the inflammatory process. This review discusses the role of TRPV1 and TRPA1 in the modulation of inflammatory genes that leads to or maintains CNI in sensory neurons and non-neuronal skin cells. In addition, this review provides a summary of current research on the intracellular sensitization pathways of both TRP channels by other endogenous inflammatory mediators that promote the self-maintenance of CNI.

Therapeutic effect of the combined treatment of mecobalamin and salvia miltiorrhiza ligustrazine on diabetic peripheral neuropathy / 中国基层医药

Objective To learn therapeutic effect of the combined treatment of mecobalamin and salvia milti-orrhiza ligustrazine on diabetic peripheral neuropathy.To provide effective and reliable operation method for the treat-ment of disease.Methods 163 cases with diabetic peripheral neuropathy were randomly divided into observation group(86 cases)and control group(77 cases).The observation group was treated with mecobalamin combined salvia miltiorrhiza ligustrazine,the control group was treated with mecobalamin.The sensory conduction velocity (SNCV) and motor conduction velocity (MNCV)were measured in the two groups before and after treatment.The therapeutic effects were evaluated after one course.Results The MNCV and SNCV of the two groups were higher than before treatment,the difference was statistically significant (t =24.298,25.546,18.737,15.733,14.284,14.886,9.337, 9.402,all P 0.05).Conclusion In the treatment of diabetic peripheral neuropathy,the com-bined treatment of mecobalamin and salvia miltiorrhiza ligustrazine has better curative effect and low incidence rate of adverse reaction,with good clinical application value.

01-1Molecular mechanisms of thermosensation through TRP channels / 日本温泉気候物理医学会雑誌

  TRP (transient receptor potential) channels were first described in Drosophila in 1989, and in mammals, TRP channels comprise six related protein families (TRPC, TRPV, TRPM, TRPA, TRPML, TRPP). One subunit of the TRP channel is composed of six transmembrane domains and a putative pore region with both amino and carboxyl termini on the cytosolic side. It is thought that the subunits form functional channels as homo- or hetero-tetramers. TRP channels are best recognized for their contributions to sensory transduction, responding to temperature, nociceptive stimuli, touch, osmolarity, pheromones and other stimuli from both within and outside the cell. Among the huge TRP super family of ion channels, some have been proven to be involved in thermosensation detecting ambient temperatures from cold to hot. There are now ten thermosensitive TRP channels (TRPV1, TRPV2, TRPV3, TRPV4, TRPM2, TRPM3, TRPM4, TRPM5, TRPM8 and TRPA1) with distinct temperature thresholds for their activation. Because temperature ranges above 43 degree C or below 15 degree C are considered to cause pain sensation in our body, thermosensitive TRP channels whose temperature thresholds are in the range can be viewed as nocicpetive receptors as well. Thermosensitive TRP channels work as ‘multimodal receptors’ which respond to various chemical and physical stimuli. TRPV1, the first identified thermosensitive TRP channel, was found as a receptor for capsaicin, and later was found to have thermosensitivity. I would like to talk about the physiological significance of the thermosensitive TRP channels (TRPV1, TRPA1, TRPV4 and TRPM2). Some of the thermosensitive TRP channels are expressed in the tissues not exposed to the dynamic changes in the ambient temperature and activated by warm temperature around our body temperature, suggesting that they have some specific physiological functuions. In addition, how structure and functions of thermosensitive TRP channels were changed dynamically in the process of evolution will also be discussed.

01-1 Molecular mechanisms of thermosensation through TRP channels / 日本温泉気候物理医学会雑誌

  TRP (transient receptor potential) channels were first described in Drosophila in 1989, and in mammals, TRP channels comprise six related protein families (TRPC, TRPV, TRPM, TRPA, TRPML, TRPP). One subunit of the TRP channel is composed of six transmembrane domains and a putative pore region with both amino and carboxyl termini on the cytosolic side. It is thought that the subunits form functional channels as homo- or hetero-tetramers. TRP channels are best recognized for their contributions to sensory transduction, responding to temperature, nociceptive stimuli, touch, osmolarity, pheromones and other stimuli from both within and outside the cell. Among the huge TRP super family of ion channels, some have been proven to be involved in thermosensation detecting ambient temperatures from cold to hot. There are now ten thermosensitive TRP channels (TRPV1, TRPV2, TRPV3, TRPV4, TRPM2, TRPM3, TRPM4, TRPM5, TRPM8 and TRPA1) with distinct temperature thresholds for their activation. Because temperature ranges above 43 degree C or below 15 degree C are considered to cause pain sensation in our body, thermosensitive TRP channels whose temperature thresholds are in the range can be viewed as nocicpetive receptors as well. Thermosensitive TRP channels work as ‘multimodal receptors’ which respond to various chemical and physical stimuli. TRPV1, the first identified thermosensitive TRP channel, was found as a receptor for capsaicin, and later was found to have thermosensitivity. I would like to talk about the physiological significance of the thermosensitive TRP channels (TRPV1, TRPA1, TRPV4 and TRPM2). Some of the thermosensitive TRP channels are expressed in the tissues not exposed to the dynamic changes in the ambient temperature and activated by warm temperature around our body temperature, suggesting that they have some specific physiological functuions. In addition, how structure and functions of thermosensitive TRP channels were changed dynamically in the process of evolution will also be discussed.