scholarly journals Sensory nerve conduction in the caudal nerves of rats with diabetes

2011 ◽  
Vol 26 (2) ◽  
pp. 121-124 ◽  
Author(s):  
Celina Cordeiro de Carvalho ◽  
Juliana Netto Maia ◽  
Otávio Gomes Lins ◽  
Sílvia Regina Arruda de Moraes

PURPOSE: To investigate sensory nerve conduction of the caudal nerve in normal and diabetic rats. METHODS: Diabetes was induced in twenty 8-weeks old Wistar male rats. Twenty normal rats served as controls. Caudal nerve conduction studies were made before diabetes induction and the end of each week for six consecutive weeks. The caudal nerve was stimulated distally and nerve potentials were recorded proximally on the animal's tail using common "alligator" clips as surface electrodes. RESULTS: After induction, nerve conduction velocities (NCV) increased slower in the diabetic than in the control group. Sensory nerve action potentials (SNAP) conduction velocities increased slower in the diabetic than in the control group (slope of regression line: 0.5 vs 1.3m/s per week; NCV in the 15th week = 39±3m/s vs 44±4m/s). Tukey's tests showed differences between groups at the 11th, 13th and 15th weeks old. From the 10th week on, SNAP amplitudes increased faster in the diabetic than in the control group (slopes of the regression line: 10 vs 8µV per week; SNAP amplitudes in the 15th week: 107±23µV vs 85±13µV). Differences at the 12th, 13th and 15th weeks were significant. CONCLUSION: In diabetic rats nerve conduction velocities were slower whereas amplitudes were larger than in normal rats.

2016 ◽  
pp. 292-311
Author(s):  
Eric J. Sorenson

Sensory nerve action potentials (SNAPs) are an important component of an electrodiagnostic test of peripheral nerves and can localize lesions either proximal or distal to the dorsal root ganglia. They are among the most sensitive measures of peripheral nerve dysfunction, and can provide information about the pathophysiology of the neuropathy, suggesting demyelination or axonal loss in some cases. Because SNAPs are much smaller than compound muscle action potentials, they are technically more difficult to study. Temperature will have a greater impact on SNAPs than motor potentials, with cooler limb temperatures leading to longer latencies, slower conduction velocities, and larger amplitudes. Responses are commonly averaged 3 to 5 times to minimize the effect of the background noise on the waveforms. Distance from the electrical generator and inter-electrode distance will also impact the appearance and size of the nerve potential waveform. This chapter reviews the concepts and applications of sensory nerve action potentials and sensory nerve conduction studies.


2009 ◽  
pp. 239-256
Author(s):  
Eric J. Sorenson

Nerve conduction studies are an invaluable addition to clinical electrophysiology testing. SNAPs are a sensitive and specific measure of function in the peripheral sensory pathways. These studies confirm whether large myelinated axons are affected by an underlying abnormality. When an area that is affected is clinically tested, nerve conduction studies can help to distinguish between a preganglionic (i.e., root level or higher) and a postganglionic (i.e., peripheral) process.


2009 ◽  
Vol 67 (1) ◽  
pp. 69-73 ◽  
Author(s):  
Dante Guilherme Velasco Hardoim ◽  
Guilherme Bueno de Oliveira ◽  
João Aris Kouyoumdjian

OBJECTIVE: To compare a long-term carpal tunnel syndrome (CTS) on nerve conduction studies (NCS) in hands treated non-surgically. METHOD: We retrospectively selected 261 symptomatic CTS hands (166 patients), all of them confirmed by NCS. In all cases, at least 2 NCS were performed in an interval greater than 12 months. Cases with associated polyneuropathy were excluded. NCS parameters for CTS electrodiagnosis included a sensory conduction velocity (SCV) <46.6 m/s (wrist to index finger, 14 cm) and distal motor latency (DML) >4.25 ms (wrist to APB, 8 cm). RESULTS: 92.8% were women; mean age was 49 years (20-76); the mean interval between NCS was 47 months (12-150). In the first exam, the median sensory nerve action potential (SNAP) and the compound action muscular potential were absent in 9.8% and 1.9%, respectively. In the second/last exam, SCV worsened in 54.2%, remained unchanged in 11.6% and improved in 34.2%. SNAP amplitude worsened in 57.7%, remained unchanged in 13.1% and improved in 29.2%. DML worsened in 52.9%, remained unchanged in 7.6% and improved in 39.5%. Overall, NCS parameters worsened in 54.9%, improved in 34.3% and remained unchanged in 10.8%. CONCLUSION: Long-term changing in NCS of CTS hands apparently were not related to clinical symptomatology and could lead to some difficulty in clinical correlation and prognosis. Aging, male gender and absent SNAP were more related to NCS worsening, regardless the mean interval time between the NCS.


Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1522
Author(s):  
Yeek Tat Ng ◽  
Sonia Chew Wen Phang ◽  
Gerald Chen Jie Tan ◽  
En Yng Ng ◽  
Nevein Philip Botross Henien ◽  
...  

Chronic hyperglycemia increases oxidative stress, activates inflammatory pathways and reduces nerve growth factor (NGF) among diabetic patients, which contribute to development of diabetic peripheral neuropathy (DPN). Tocotrienol-Rich Vitamin E (Tocovid) possesses potent antioxidant and anti-inflammatory properties which are postulated to target these pathogeneses in order to ameliorate DPN. This study aims to evaluate the effects of Tocovid on nerve conduction parameters and serum biomarkers among diabetic patients. This multicenter, prospective, randomized, double-blind, placebo-controlled clinical trial was conducted on 80 eligible participants. The intervention group (n = 39) was randomly allocated to receive 200 mg of Tocovid twice a day, and the control group (n = 41) received placebo twice a day. At the end of eight weeks, the nerve conduction parameters, as assessed by nerve conduction study, as well as serum biomarkers (NGF, malondialdehyde, vascular cell adhesion molecule 1, tumor necrosis factor receptor 1 and thromboxane B2) were compared between the two groups. Compared to placebo, Tocovid significantly improves the nerve conduction velocities of all nerves (+1.25 m/s, interquartile range [IQR] 3.35, p < 0.001, median nerve; +1.60 m/s, IQR 1.80, p < 0.001, sural nerve; +0.75 m/s, IQR 2.25, p < 0.001, tibial nerve). Meanwhile, the levels of serum NGF were significantly higher in the Tocovid group as compared to placebo at eight weeks post-intervention. Participants receiving Tocovid illustrated highly significant improvement in terms of nerve conduction velocities for all nerves tested after eight weeks of supplementation. In addition, Tocovid supplementation elevated the levels of serum NGF, in which its increase is postulated to reflect enhanced neuronal functions. This novel finding suggests that Tocovid could be a disease-modifying agent targeting serum NGF to improve nerve conduction velocities.


2017 ◽  
Vol 2 (4) ◽  
pp. 172-177
Author(s):  
Saeid Tanoorsaz ◽  
Naser Behpoor ◽  
Vahid Tadibi

Introduction: Cardiac apoptosis is one of the most important cardiovascular complications of diabetes. We aimed to investigate the changes of caspase-8, Bcl-2, and N-terminal pro B-type natriuretic peptide (NT-proBNP) in cardiac tissue after 4 weeks of aerobic exercise in male rats with diabetes. Methods: Forty adult male rats were randomly allocated to healthy control, diabetes, control + exercise and exercise + diabetes groups. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) solution (55 mg/kg). Two weeks after injection, fasting blood glucose levels were measured. After the induction of diabetes, the exercise program was performed for 4 weeks (5 sessions per week) at a speed of 15 to 18 m/min for 25 to 44 minutes. Forty-eight hours after the last training session, the subjects were anesthetized and the heart muscle was removed. Caspase-8, Bcl-2 and NT-proBNP levels were measured by ELISA method. Results: The induction of diabetes in the control group resulted in a significant increase in caspase-8, and NT-proBNP levels while an insignificant increase was observed for Bcl-2 levels (P<0.05). In non-diabetic groups, exercise caused no changes in caspase-8, NT-proBNP and Bcl-2 (P<0.05). Exercise in diabetic groups significantly decreased NT-proBNP while no changes were observed in caspase-8 and Bcl-2 (P<0.05). Conclusion: Our findings showed that diabetes increases the pro-apoptotic and anti-apoptotic agent. In addition, 4 weeks of regular aerobic exercises can be used as a non-pharmacological strategy to reduce the complications of apoptosis in diabetic cardiomyocytes.


2020 ◽  
Vol 10 (4) ◽  
pp. 136-141
Author(s):  
Mohammed Salah Elmagzoub ◽  
Ahmed Hassan Ahmed ◽  
Hussam M A Hameed

Background: Nerve conduction studies (NCSs) help in delineating the extent distribution of neural lesion, and the diagnosis of peripheral nerve disorders. Because normative nerve conduction parameters were not yet established in Sudan EMG laboratories, this study aims towards having our own reference values, as we are using the American and British parameters. This will allow avoiding the discrepancies that might be induced by many factors. Methods: NCSs were performed in 200 Median nerves of 100 adult healthy Sudanese subjects using standardized techniques. Results: The median SNAP (sensory nerve action potential) values were as follows: distal latency, 2.6±3 ms with a range of (2.3-2.9); peak latency, 3.5±0.5 ms (3.0-4.0); amplitude, 47.7±18.0μV (29.7-65.7); conduction velocity, 53.0±7.8 m/s (45.2-60.8). The following values were obtained for the Median nerve CMAP (compound muscle action potential) at wrist stimulation: distal latency, 3.5±0.5 ms with a range of (3.0-4.0); peak latency, 9.4± 1.0 ms (8.4-10.4); duration, 5.9±0.9 ms (5.0-6.8); amplitude, 12.3±2.5 mV (9.8-14.8); area, 43.0±10.4 mVms (32.6-53.4); conduction velocity, 63.6±6.2 m/s (57.4-69.8). The F wave was 28.4±1.8 ms (26.6-30.2). Conclusion: The overall mean sensory and motor nerve conduction parameters for the tested nerve compared favorably with the existing literature with some discrepancies that were justified.


2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Matthew Ritch ◽  
Omer Suhaib ◽  
Yuebing Li

Background: Sciatic neuropathy is differentiated from lumbosacral radiculopathy based on the finding of abnormal sensory nerve action potentials (SNAPs). Cases of sciatic neuropathy with intact SNAPS have not been well described. Methods: A retrospective analysis of 12 patients with sciatic neuropathy in a single institution. Results: We describe 12 patients in whom a sciatic neuropathy was diagnosed based on a combination of history, physical exam, radiological and electrodiagnostic (EDX) findings. Lower extremity SNAPs were found to be within normal range in all patients, although SNAP amplitude asymmetry between both sides was observed in 3. Included patients were young (mean age of 40.3 years) and mostly female (9 patients). Conclusions: Sciatic neuropathy may occur with a relative sparing of sensory fibers. Recognition of this group of patients should help to avoid making a misdiagnosis of lumbosacral radiculopathy.


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