Mean Nerve Conduction Velocity Research Articles

The effect of Angipars on diabetic neuropathy in STZ-induced diabetic male rats: a study on behavioral, electrophysiological, sciatic histological and ultrastructural indices.

Diabetes mellitus is the most common metabolic disease with a high prevalence rate in human society that eventually leads to the peripheral nervous system complications in a great number of patients. In the present study, the effects of Angipars on nerve conduction velocity, histological alterations, and behavioral indices were investigated. Diabetes was induced in male rats by intraperitoneal injection of streptozotocin (STZ). Six weeks after STZ injection, animals were divided into five groups control, vehicle, and 3 experimental groups. The vehicle group received 1 mL distilled water daily for two weeks and three experimental groups received, respectively, intraperitoneal injection of 5, 10, and 20 mg/kg Angipars daily for two weeks. Intraperitoneal injection of Angipars, in some extent, could significantly improve behavioral indices of the experimental groups as compared to the vehicle group. Furthermore, mean nerve conduction velocity in the vehicle group showed significant difference with that in the control and the 2nd experimental groups; therefore, Angipars could increase nerve conduction velocity in neuropathic rats. Overall, Angipars exerted positive effects on the treatment and reduction of physiologic symptoms and improvement of sciatic morphological injuries in neuropathic rats.

Clinical and Electrophysiological Changes after Open Carpal Tunnel Release: Preliminary Study of 25 Hands

Background: Electrophysiological study has been known as a useful method to evaluate the therapeutic effect of operation in idiopathic carpal tunnel syndrome (CTS). The purpose of this study was to evaluate the clinical and electrophysiological changes after carpal tunnel release (CTR) compared to the preoperative results. Methods: We analyzed the changes of nerve conduction study (NCS) before and after minimal open carpal tunnel release in 18 patients (25 hands) with CTS. Follow-up study was performed over 6 months after operation. Results: Clinical improvement was seen in all cases after CTR. In contrast, electrophysiological improvement was various depending on the parameters; the mean median sensory latency and nerve conduction velocity (NCV) improved significantly (p = 0.001). The mean median motor latency also improved, but NCV and compound muscle action potential (CMAP) amplitude did not change. The extent of improvement was evident in moderate CTS, but not in severe CTS. Conclusions: In this preliminary study, all subjects who underwent CTR achieved a clinical relief along with a significant improvement of electrophysiological parameters such as median sensory latency, sensory NCV and median distal motor latency. After CTR, a number of cases with mild to moderate CTS showed a prominent improvement of clinical and electrophysiological parameters, while fewer improvements were seen in severe CTS, although it did not reach the statistical significance. (Korean J Clin Neurophysiol 2014;16:21-26)

Efficacy and safety of methylcobalamin, alpha lipoic acid and pregabalin combination versus pregabalin monotherapy in improving pain and nerve conduction velocity in type 2 diabetes associated impaired peripheral neuropathic condition. [MAINTAIN]: Results of a pilot study.

Background and Objective:To assess whether methylcobalamin and alpha lipoic acid (ALA) added to pregabalin provide additional benefit compared to pregabalin alone in type 2 diabetes mellitus associated peripheral neuropathy.Setting and Design:An open label, randomized, controlled parallel-group pilot study.Materials and Methods:Thirty adult patients with type 2 diabetes mellitus with symptoms of peripheral neuropathy for ≥6 months were randomized to receive pregabalin 75 mg, methylcobalamin 750 μg, and ALA 100 mg (PMA, n = 15); or pregabalin 75 mg (PG, n = 15) for 12 weeks. Assessment variables were numeric rating scale (NRS), sleep interference scores (SIS), response rate to pain, and global assessment for the usefulness of therapy. The nerve conduction velocity was assessed for sensory and motor nerves. Safety assessment included adverse events reported by the patients, clinical laboratory, and general medical, neurological examinations.Statistical Analysis:Efficacy analyses were done on per-protocol (PP) population, whereas safety analyses were done on intent-to-treat (ITT) population.Results:Significant improvement was seen in pain and sleep interference in both groups. Mean nerve conduction velocity of left common peroneal nerve (CPN) showed significant improvement in PMA group at week 12 compared to baseline (P = 0.018). For right CPN both groups showed significant improvement. (PMA, P = 0.002, PG, P = 0.007). For sensory testing, at week 12, right superficial peroneal nerve showed reduction in nerve conduction velocity in PG group compared to baseline (P = 0.043).Conclusion:Methylcobalamine, ALA and pregabalin combination provides pain relief and improves sleep interference. Addition of methylcobalamin and ALA to pregabalin improves the nerve function. Due to small sample size, most of the efficacy parameters could not reach significant difference between groups; hence benefit of the 3-drug-combimation should be interpreted with reservation.

Efficacy and safety of methylcobalamin, alpha lipoic acid and pregabalin combination versus pregabalin monotherapy in improving pain and nerve conduction velocity in type 2 diabetes associated impaired peripheral neuropathic condition. [MAINTAIN]: Results of a pilot study.

Background and Objective: To assess whether methylcobalamin and alpha lipoic acid (ALA) added to pregabalin provide additional benefit compared to pregabalin alone in type 2 diabetes mellitus associated peripheral neuropathy. Setting and Design: An open label, randomized, controlled parallel-group pilot study. Materials and Methods: Thirty adult patients with type 2 diabetes mellitus with symptoms of peripheral neuropathy for ≥6 months were randomized to receive pregabalin 75 mg, methylcobalamin 750 μg, and ALA 100 mg (PMA, n = 15); or pregabalin 75 mg (PG, n = 15) for 12 weeks. Assessment variables were numeric rating scale (NRS), sleep interference scores (SIS), response rate to pain, and global assessment for the usefulness of therapy. The nerve conduction velocity was assessed for sensory and motor nerves. Safety assessment included adverse events reported by the patients, clinical laboratory, and general medical, neurological examinations. Statistical Analysis: Efficacy analyses were done on per-protocol (PP) population, whereas safety analyses were done on intent-to-treat (ITT) population. Results: Significant improvement was seen in pain and sleep interference in both groups. Mean nerve conduction velocity of left common peroneal nerve (CPN) showed significant improvement in PMA group at week 12 compared to baseline (P = 0.018). For right CPN both groups showed significant improvement. (PMA, P = 0.002, PG, P = 0.007). For sensory testing, at week 12, right superficial peroneal nerve showed reduction in nerve conduction velocity in PG group compared to baseline (P = 0.043). Conclusion: Methylcobalamine, ALA and pregabalin combination provides pain relief and improves sleep interference. Addition of methylcobalamin and ALA to pregabalin improves the nerve function. Due to small sample size, most of the efficacy parameters could not reach significant difference between groups; hence benefit of the 3-drug-combimation should be interpreted with reservation.

Sciatic nerve repair with tissue engineered nerve: Olfactory ensheathing cells seeded poly(lactic-co-glygolic acid) conduit in an animal model

Background and Aim:Synthetic nerve conduits have been sought for repair of nerve defects as the autologous nerve grafts causes donor site morbidity and possess other drawbacks. Many strategies have been investigated to improve nerve regeneration through synthetic nerve guided conduits. Olfactory ensheathing cells (OECs) that share both Schwann cell and astrocytic characteristics have been shown to promote axonal regeneration after transplantation. The present study was driven by the hypothesis that tissue-engineered poly(lactic-co-glycolic acid) (PLGA) seeded with OECs would improve peripheral nerve regeneration in a long sciatic nerve defect.Materials and Methods:Sciatic nerve gap of 15 mm was created in six adult female Sprague-Dawley rats and implanted with PLGA seeded with OECs. The nerve regeneration was assessed electrophysiologically at 2, 4 and 6 weeks following implantation. Histopathological examination, scanning electron microscopic (SEM) examination and immunohistochemical analysis were performed at the end of the study.Results:Nerve conduction studies revealed a significant improvement of nerve conduction velocities whereby the mean nerve conduction velocity increases from 4.2 ΁ 0.4 m/s at week 2 to 27.3 ΁ 5.7 m/s at week 6 post-implantation (P < 0.0001). Histological analysis revealed presence of spindle-shaped cells. Immunohistochemical analysis further demonstrated the expression of S100 protein in both cell nucleus and the cytoplasm in these cells, hence confirming their Schwann-cell-like property. Under SEM, these cells were found to be actively secreting extracellular matrix.Conclusion:Tissue-engineered PLGA conduit seeded with OECs provided a permissive environment to facilitate nerve regeneration in a small animal model.

Evaluation of spectrum of peripheral neuropathy in predialysis patients with chronic kidney disease

Introduction: Neurological complications secondary to the uremic state, contribute largely to the morbidity and mortality in patients with renal failure. The prevalence of peripheral neuropathy remains high in advanced renal dysfunction. Materials and methods: The present cross-sectional study was conducted on 100 adult patients of chronic kidney disease between 18 and 75 years of age with serum creatinine greater than 2 mg/dL. Apart from routine examination and baseline investigations, detailed history was elicited pertaining to patients’ neurological symptoms, and scored according to the Neurological Symptom Score. Motor nerve conduction velocity was measured from right median, ulnar, peroneal, and tibial nerves. Results: It was observed that neurological symptoms increased steadily with raise in serum creatinine. The mean nerve conduction velocities (NCVs) of right median nerve, ulnar nerve, peroneal nerve, and tibial nerve were 51.34 ± 6.07, 53.04 ± 5.91, 44.72 ± 6.14, and 44.20 ± 5.17, respectively. The NCVs of all the tested nerves decreased significantly with increase in serum creatinine levels (p < 0.01): 70% of the patients had uremic polyneuropathy; 6% had asymptomatic neuropathy, 51% had symptomatic non-disabling neuropathy, while disabling neuropathy was seen in 13% of the patients. Conclusion: Our data suggests that NCV testing when complimented with meticulous neurological assessment can provide invaluable input. These tests apart from helping us detect neuropathy in advanced renal dysfunction; can also detect the disease in largely asymptomatic patients which avoids the necessity to order for detailed neurophysiological investigation

Using eggshell membrane as nerve guide channels in peripheral nerve regeneration.

The aim of this study was to evaluate the final outcome of nerve regeneration across the eggsell membrane (ESM) tube conduit in comparison with autograft. Thirty adult male rats (250-300 g) were randomized into (1) ESM conduit, (2) autograft, and (3) sham surgery groups. The eggs submerged in 5% acetic acid. The decalcifying membranes were cut into four pieces, rotated over the teflon mandrel and dried at 37(°)C. The left sciatic nerve was surgically cut. A 10-mm nerve segment was cut and removed. In the ESM group, the proximal and distal cut ends of the sciatic nerve were telescoped into the nerve guides. In the autograft group, the 10 mm nerve segment was reversed and used as an autologous nerve graft. All animals were evaluated by sciatic functional index (SFI) and electrophysiology testing. The improvement in SFI from the first to the last evalution in ESM and autograft groups were evaluated. On days 49 and 60 post-operation, the mean SFI of ESM group was significantly greater than the autograft group (P< 0.05). On day 90, the mean nerve conduction velocity (NCV) of ESM group was greater than autograft group, although the difference was not statistically significant (P> 0.05). These findings demonstrate that ESM effectively enhances nerve regeneration and promotes functional recovery in injured sciatic nerve of rat.

An electrophysiological study of peripheral polyneuropathy in brucellosis.

Brucellosis is an anthropozoonotic disease with heterogeneous clinical presentations. This study aims to investigate the peripheral nervous system (PNS) involvement in brucellosis. A total of 57 patients with brucellosis, and 42 age- and gender-matched healthy subjects were enrolled into the study. We performed motor conduction studies that included bilateral median, ulnar, tibial and peroneal nerves, and sensory nerve investigations from bilateral median, ulnar, radial, sural and medial plantar nerves. Among patients with brucellosis, 21 had neuropathic symptoms. Of these, 9 had abnormalities in nerve conduction studies. The electromyographic testing revealed abnormalities in 2 patients without neuropathic symptoms. Overall, 11 patients (4 males, 7 females) with brucellosis (19.3%) had polyneuropathy (PNP). The mean age of patients with PNP was 52.63 ± 19.06 years, being significantly higher than those without PNP (P = 0.006). The mean duration of brucellosis was also longer in patients with PNP, but not significant. The mean distal latency (DL) and nerve conduction velocity (NCV) values were almost always longer in patients with brucellosis than controls, though not statistically significant. Our results showed that brucellosis causes clinical or subclinical peripheral PNP, and should therefore be considered as a cause of PNP, especially in endemic regions.

Large-area irradiated low-level laser effect in a biodegradable nerve guide conduit on neural regeneration of peripheral nerve injury in rats

This study used a biodegradable composite containing genipin-cross-linked gelatin annexed with β-tricalcium phosphate ceramic particles (genipin-gelatin-tricalcium phosphate, GGT), developed in a previous study, as a nerve guide conduit. The aim of this study was to analyse the influence of a large-area irradiated aluminium–gallium–indium phosphide (AlGaInP) diode laser (660nm) on the neural regeneration of the transected sciatic nerve after bridging the GGT nerve guide conduit in rats. The animals were divided into two groups: group 1 comprised sham-irradiated controls and group 2 rats underwent low-level laser (LLL) therapy. A compact multi-cluster laser system with 20 AlGaInP laser diodes (output power, 50mW) was applied transcutaneously to the injured peripheral nerve immediately after closing the wound, which was repeated daily for 5min for 21 consecutive days. Eight weeks after implantation, walking track analysis showed a significantly higher sciatic function index (SFI) score (P<0.05) and better toe spreading development in the laser-treated group than in the sham-irradiated control group. For electrophysiological measurement, both the mean peak amplitude and nerve conduction velocity of compound muscle action potentials (CMAPs) were higher in the laser-treated group than in the sham-irradiated group. The two groups were found to be significantly different during the experimental period (P<0.005). Histomorphometric assessments revealed that the qualitative observation and quantitative analysis of the regenerated nerve tissue in the laser-treated group were superior to those of the sham-irradiated group. Thus, the motor functional, electrophysiologic and histomorphometric assessments demonstrate that LLL therapy can accelerate neural repair of the corresponding transected peripheral nerve after bridging the GGT nerve guide conduit in rats.

Nerve conduction, visual evoked responses and electroretinography in tunnel workers previously exposed to acrylamide and N-methylolacrylamide containing grouting agents

The study examines possible persisting effects on the peripheral nervous system and visual system in tunnel workers previously exposed to acrylamide and N-methylolacrylamide during grouting work. We compared neurophysiological function in 44 tunnel workers previously exposed during grouting operations (2–10 years post exposure), with 49 tunnel workers with no history of exposure to acrylamide. Nerve conduction velocities (NCV), distal delay, F-response and amplitude in median and ulnar nerves of the right arm, peroneal, sural and tibial nerves of the right leg, visual evoked response (VER) and electroretinography (ERG) were measured. VER and ERG were also performed in 24 subjects more recently exposed to acrylamide grout (16 months post exposure). Exposure to acrylamide containing grouts was assessed by questionnaires. A statistically significant reduction in the mean sensory NCV of the sural nerve (p=0.005), as well as a non-significant reduction of sural amplitude was found in the previously exposed group compared to the control group. VER latencies to the onset of the occipital potential (N75) were prolonged in both exposed groups compared to the control group (p<0.05). ERG 30 Hz flicker amplitude was reduced in the recently exposed group compared to the referents (p<0.05). The results indicate slight subclinical, but persistent toxic effects in the sural nerve and the visual system in tunnel workers exposed to N-methylolacrylamide and acrylamide during grouting operations.

Two measurement methods of motor ulnar nerve conduction velocity at the elbow: A comparative study

Electrodiagnostically, localization of ulnar nerve lesions, which commonly occurs at the elbow, is sometimes problematic. Measurement of motor ulnar nerve conduction velocity (NCV) at the elbow is amongst the most popular techniques to diagnose ulnar neuropathy. In this method, recording from the first dorsal interosseous muscle (FDI) is suggested to be more sensitive than the abductor digiti minimi (ADM). However, the criterion for abnormality is based on the normal values recorded from ADM. To determine the normal values of Ulnar motor NCV using FDI and ADM and the difference between the values obtained from FDI and ADM. Additionally, to measure the amount of reduction of NCV across the elbow for each recording site. This was a cross-sectional study performed on 50 healthy volunteers (100 nerves). All subjects were in the same condition regarding joint position and surface hand temperature. We recorded ulnar NCV at forearm and across the elbow with recording electrode on both FDI and ADM, simultaneously. The mean NCV at the elbow recorded from ADM and FDI were 62.65 +/- 7.62 m/s and 60.49 +/- 7.42 m/s respectively, showing significant difference. The ulnar minimum normal NCVs recorded from ADM and FDI were 47.4 m/s and 45.6 m/s, respectively. If the normal values of ADM are used as the basis for recording from FDI, it could lead to false-positive diagnosis of cases suspicious of ulnar neuropathy. Therefore it is preferred to use the normal values of FDI itself while recording.

Is diabetic dermopathy a sign for severe neuropathy in patients with diabetes mellitus? Nerve conduction studies and symptom analysis

Objective To assess if diabetic dermopathy (DD) is a sign for severe polyneuropathy (PNP). Methods We investigated the clinical and electrophysiological characteristics of 166 diabetic men (59.5+11.1 years) with different degrees of peripheral nerve involvement. Results All of the clinical variables were more common in patients with diabetic foot ulcers (DF) than in patients with sole PNP ( P<0.001). Only the loss of superficial and vibration sense was more common in the DF patients than the DD patients ( P<0.02). Nerve conduction studies showed the mean compound muscle action potentials (CMAP) were smaller in the DD and DF patients than the PNP patients for peroneal, median and ulnar nerves ( P<0.01). The mean nerve conduction velocities (NCV) of all nerves were slower in the DD and DF patients in compared to sole PNP patients ( P<0.01). The mean distal latencies (DL) of the DD/DF patients were longer than the PNP group. Conclusions The DD and DF patients did not significantly differ in CMAP, NCV, and DL. Significance: Both clinical and electrophysiological features of DD and DF are similar, and significant different than PNP alone. These results suggest that DD is an important clinical sign for more severe neuropathic impairment.

An experimental study on reconstruction of rhesus tissue-engineered peripheral nerve

目的 评价组织工程化周围神经修复猕猴 4 cm尺神经缺损的实验效果,为临床研究提供资料.方法分别用 6种移植物桥接 4 cm尺神经缺损. A组:自体 BMSCs+去细胞同种异体神经支架; B组:自体 SCs+去细胞同种异体神经支架; C组:自体 BMSCs+ PLGA支架导管; D组: 去细胞同种异体神经支架; E组: PLGA支架导管; F组:自体神经.通过功能学、神经电生理学及组织学研究评价各自的实验效果.结果 A、 B、 C三种组织工程化神经实验组,术后 6个月神经电生理和组织学检查,能引起小鱼际肌群产生复合动作电位的潜伏期、复合动作电位的 最大振幅、神经传导速度和再生的神经纤维数目与自体神经移植组 (F组 )相比差异无显著性意义( P >0.05),但分别大于未加细胞的支架组( D、 E组),差异有显著意义( P< 0.05).结论用自体源 SCs或 BMSCs作种子细胞与去细胞同种异体神经支架,或自体源 BMSCs与 PLGA支架导管构建不同的组织工程化周围神经,修复猕猴 4 cm尺神经缺损均取得较好的效果 。

Study on the reconstruction of rhesus tissue-engineered peripheral nerve using acellular allogenic nerve with implanted autologous mesenchymal stem cells or Schwann cells

目的 评价用自体源骨髓间充质干细胞(MSCs)或许旺细胞(SCs)作种子细胞,与去细胞同种异体神经构建的组织工程化外周神经修复猕猴尺神经4 cm缺损的实验效果,为临床研究提供资料.方法分别用4种移植物桥接猕猴4 cm尺神经缺损.A组:种植自体MSCs的去细胞同种异体神经;B组:种植自体SCs的去细胞同种异体神经;C组:去细胞同种异体神经;D组:自体神经移植.通过功能学、神经电生理学及组织学指标评价各组修复神经缺损的效果.结果 A、B组术后6个月能引起小鱼际肌群产生复合动作电位的潜伏期、复合动作电位的最大振幅、神经传导速度和再生的神经纤维数目与自体神经移植组相比无统计学意义(P＞0.05);但A、B、C、D组分别与C组相比,差异有统计学意义(P＞0.05).结论用自体源SCs或MSCs作种子细胞,与去细胞同种异体神经构建的组织工程化外周神经修复猕猴4 cm尺神经缺损,均能取得与自体神经移植相近的效果。

Avoidance of direct injury to the peripheral nerve with maxacalcitol (22oxa-1,25(OH)2D3) in rats.

Secondary hyperparathyroidism is one of the most common complications in patients with long-term end-stage renal disease. A recent report has stated that high doses of vitamin D derivatives injected directly into the parathyroid glands can reduce serum parathyroid hormone levels and suppress further enlargement of the parathyroid glands without side-effects. Maxacalcitol (22oxa-1,25(OH)(2)D(3); OCT) is a new vitamin D derivative that can be administered intravenously, and is available in Japan. Direct injection of OCT into enlarged parathyroid glands is a promising new treatment for moderate renal hyperparathyroidism. It is considered to be safe for surrounding tissues, such as peripheral nerves, but the actual effects of OCT on nerves have not yet been documented. We measured nerve conduction velocity (NCV) in 24 rat femoral nerves soaked in saline, ethanol, or OCT at various concentrations. Nerves from each group (saline, ethanol, OCT groups) were also examined by microscopy. The mean NCV of rat femoral nerves was 33.67 +/- 1.39 m/s in the saline group. In the OCT group, the velocities were not changed at any of the concentrations tested, and there were no significant differences in NCVs between the saline and OCT groups. In the 50% ethanol group, the velocity decreased significantly to 8.98 +/- 4.78 m/s (P < 0.01). A histological study demonstrated the nerves soaked in OCT at 10 microg/mL to essentially be intact, while those soaked in anhydrous ethanol were damaged. This study demonstrated that OCT administration does not affect peripheral NCV, indicating that OCT could possibly be used for the treatment of moderate renal hyperparathyroidism safely without nerve damage.

Sex difference in brain nerve conduction velocity in normal humans

Nerve conduction velocity (NCV), the speed at which impulses travel along nerves, has been extensively determined in human peripheral nerves because of its clinical utility. In contrast, almost no studies have been made of human brain NCV. We determined brain NCVs in the visual nerve pathway for 185 male and 200 female university students ages 18–25 years. In each of three independent test conditions, we found that the mean NCV of male students is about 4% faster than in females ( P≤0.0001 for each condition). These male students also have a shorter reaction time in each of seven different RT tests than do females, even though, on the null hypothesis of equal NCVs, we would expect males to have longer RT times because of their greater physical size. Four of these comparisons are significant at or below the 0.001 level. These males also increase their NCVs with increasing age, in contrast to females. These sex differences in NCV parallel reported sex differences in age changes in white matter in the brain. These age changes may largely explain these NCV differences.

Optimal blood glucose control during 18 years preserves peripheral nerve function in patients with 30 years' duration of type 1 diabetes.

To assess the association between 18 years of mean HbA(1c) and nerve conduction parameters of the lower limb in patients with type 1 diabetes of 30 years' duration. HbA(1c) has been examined prospectively since 1982 in a group of 39 patients with type 1 diabetes. Mean age at baseline was 25 years (range 18-40) with 12 years' disease duration. The mean age at diagnosis of diabetes was 12.5 years. Nerve function of lower limbs was assessed at baseline, after 8 years, and after 18 years. A total of 23 men and 16 women were studied. Mean age was 43 years. Mean HbA(1c) was 8.2% (range 6.6-11.3) during 18-year follow-up. Nerve conduction velocity (NCV) and nerve action potential amplitude (NAPA) at the last examination were significantly associated with mean HbA(1c) (P < 0. 05). From 1982 to 1999, there was a significant reduction in nerve function in patients with mean HbA(1c) >or=8.4% (highest tertile). For example, the mean NCV in the tibial nerve was reduced from 47 to 31 m/s (P < 0.01). The number of nerves with NCV (P < 0.01) and NAPA (P = 0.01) reduced to below the reference level in each patient was also significantly associated to mean HbA(1c). No significant associations were found between nerve function parameters, sex, disease duration, blood pressure, serum cholesterol, microalbuminuria, or smoking. The present study shows that mean HbA(1c) is a strong predictor of nerve function. Mean HbA(1c) <8.4% over 18 years was associated with near-normal nerve function.

Mixed median nerve forearm conduction velocity in the presence of focal compression neuropathy at the wrist versus peripheral neuropathy

Watson J, DiBenedetto M, Gale SD. Mixed median nerve forearm conduction velocity in the presence of focal compression neuropathy at the wrist versus peripheral neuropathy. Arch Phys Med Rehabil 2002;83:302-7. Objectives: To establish normal values for the conduction velocity of the mixed median nerve in the forearm, and to determine the use of mixed median nerve conduction velocity (NCV) studies across the forearm in the differential diagnosis of carpal tunnel syndrome (CTS), peripheral neuropathy, and CTS with peripheral neuropathy. Design: Criterion standard. Mixed median NCV studies across the forearm were added to routine CTS investigational protocols. Setting: University outpatient setting, rural referral base. Participants: Thirty healthy volunteers and 60 patients referred with symptoms and signs suggestive of CTS and/or peripheral neuropathy. Interventions: Not applicable. Main Outcome Measures: Motor sensory and mixed median nerve conduction velocity across the forearm. Results: The mean mixed median NCV across the forearm was 64.5m/s in healthy subjects and subjects with CTS. The mean mixed NCV in subjects with peripheral neuropathy was 54m/s, even in the presence of CTS. Conclusion: Mixed median NCV in the forearm added to the standard protocols is helpful in differentiating the diagnosis of CTS from peripheral neuropathy and CTS with peripheral neuropathy. © 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Acetyl-L-Carnitine (Levacecarnine) in the Treatment of Diabetic Neuropathy

To assess the efficacy and tolerability of acetyl-L-carnitine (levacecarnine; LAC) versus placebo in the treatment of diabetic neuropathy, mainly by evaluating the effects of treatment on electrophysiological parameters and pain symptoms. This was a multicentre (n = 20), randomised, double-blind, placebo-controlled, parallel-group study. 333 patients meeting clinical and/or neurophysiological criteria for diabetic neuropathy were enrolled. Patients were randomised to treatment with LAC or placebo. LAC (or placebo) was started intramuscularly at a dosage of 1000 mg/day for 10 days and continued orally at a dosage of 2000 mg/day for the remainder of the study (355 days). MAIN OUTCOME PARAMETERS AND RESULTS: The main efficacy parameter was the effect of treatment on 6- and 12-month changes from baseline in nerve conduction velocity (NCV) and amplitude in the sensory (ulnar, sural and median) and motor (median, ulnar and peroneal) nerves. The effect of treatment on pain was also evaluated by means of a visual analogue scale (VAS). Among the 294 patients with impaired electrophysiological parameters at baseline, those treated with LAC showed a statistically significant improvement in mean NCV and amplitude compared with placebo (p < 0.01). The greatest changes in NCV (at 12 months) were observed in the sensory sural nerve (7 m/sec in the LAC group vs +1.0 m/sec in the placebo group), sensory ulnar nerve (+2.9 vs +0.1 m/sec, respectively) and motor peroneal nerve (+2.7 vs -0.2 m/sec), whereas the greatest changes in amplitude were recorded in the motor peroneal nerve (+2.2 vs +0.1 mV). After 12 months of treatment, mean VAS scores for pain were significantly reduced from baseline by 39% in LAC-treated patients (p < 0.0 vs baseline) compared with 8% in placebo recipients. LAC was well tolerated over the study period. LAC was effective and well tolerated in improving neurophysiological parameters and in reducing pain over a 1-year period. LAC is, therefore, a promising treatment option in patients with diabetic neuropathy.

Ulnar nerve motor conduction to the abductor digiti minimi.

Ulnar motor study to the abductor digiti minimi is commonly performed, but a more extensive database of normative values using modern electrodiagnostic and statistical techniques and temperature control is needed for this test. Demographic subgroups of age, gender, and height should be evaluated using a large subject population to determine whether separate normal ranges should be created for subsets of the general population. In this study, 248 volunteers were tested to measure ulnar motor latency, amplitude, area, duration, and nerve conduction velocity. Side-to-side and distal-to-proximal variability was analyzed. A repeated measures analysis of variance was performed with the waveform measures as the dependent variables and age, gender, and height as independent variables. None of the results were found to vary significantly (at the P < or = 0.01 level) with the subjects' physical characteristics, and thus, the data for all subjects were pooled to create a normative database. The normal range was derived as mean +/- 2 standard deviations and at the 97th (third) percentile of observed values. Mean latency was 3.0 +/- 0.3 ms, and amplitude was 11.6 +/- 2.1 mV. Mean nerve conduction velocity was 61 m/s across all segments tested. The upper limit of normal side-to-side variability (mean + 2 standard deviations) for latency was 0.6 ms; for amplitude, it was 3.6 mV. The upper limit of normal drop in conduction velocity across the elbow was 15 m/s (at the 97th percentile). Additional data are presented for all variables measured, as well as for side-to-side variability and distal-to-proximal change.