Ulnar entrapment neuropathy in patients with type 2 diabetes mellitus: An electrodiagnostic study

Aims

This study aimed to assess the prevalence and electrophysiological features of ulnar entrapment neuropathy in patients with type 2 diabetes mellitus (DM).

Methods

Nerve conduction studies (NCS) were performed in a sample of consecutive diabetic patients aged 25–75 years, referred by the Diabetology Unit. NCS of the median, ulnar, radial, peroneal and sural nerves were performed on the non-dominant side. Median entrapment neuropathy at the wrist (MNW) and ulnar neuropathy at the elbow (UNE) and wrist (UNW) were diagnosed according to standard electrodiagnostic criteria.

Results

Sixty-four patients were enrolled, 28 male (44%), average age 61, average DM duration 14.5 years. Polyneuropathy was diagnosed in 45 subjects (70%). UNE was detected in 22 patients (34%) (4 did not have polyneuropathy), in the abductor digiti minimi in 16, the first interosseus in 14 and in both in 8. UNW was detected in 7 (11%) subjects and MNW in 40 (63%). NCS alterations consistent with ulnar neuropathy were detected in a high proportion of patients (45%), suggesting that the ulnar nerve is very susceptible to focal entrapment in DM.

Conclusions

Upper limb sensory and motor NCS, including motor conduction velocity across the elbow, should be considered in the staging of DM patients.     

Subclinical nerve dysfunction in children and adolescents with IDDM

Summary The purpose of this study was to investigate whether young insulin-dependent diabetic patients still develop peripheral nerve dysfunction when using modern multiple insulin injection therapy and to elucidate if this correlated with various disease parameters. Seventy-five patients, 7 to 20 years old with a duration of diabetes of more than 3 years, and 128 age-matched healthy control subjects underwent bilateral studies of median, peroneal, and sural nerves. Presence of diabetes lowered motor conduction velocity (p<0.0001), sensory conduction velocity (p<0.0001) and sensory nerve action potential (p<0.05) in all examined nerves. The mean change in conduction velocity induced by diabetes was –4.8 m/s in the peroneal nerve, –3.3 m/s in the median motor nerve, –2.6 m/s in the sural nerve and –2.4 m/s in the median sensory nerve. Fifty-seven percent of the patients had abnormal conduction (values outside 95% predictive interval) which was seen most often in the motor nerves, especially in the peroneal nerve (41%) followed by the median nerve (24%). In multiple regression analysis, long-term poor metabolic control and increased body length correlated with nerve dysfunction identified in most examined parameters. Three patients had signs or symptoms suggestive of neuropathy. It is concluded that despite modern multiple insulin injection therapy, with reasonably good metabolic control, nerve dysfunction is still common in children and adolescents with insulin-dependent diabetes mellitus. Risk factors are increased height and long-term poor metabolic control.Abbreviations IDDM Insulin-dependent diabetes mellitus - MIT multiple insulin injection therapy - MCV motor nerve conduction velocity - CMAP compound muscle action potential - DML distal motor latency - SCV sensory nerve conduction velocity - SNAP sensory nerve action potential     

Motor pathway function in normoalbuminuric IDDM patients

Summary Central motor pathways were studied in 17 normoalbuminuric insulin-dependent diabetic (IDDM) patients who had been diabetic for more than 20 years, and compared with findings in 17 age-, sex-, and height-matched control subjects. The central motor conduction time was calculated from recordings of the compound muscle action potentials of the abductor pollicis brevis muscle after single transcranial and spinal root magnetic stimulation. The central motor conduction time from motor cortex to cervical spinal roots was 9.8±1.65 ms in diabetic patients and 10.1±1.48 ms in control subjects. In diabetic patients with neuropathy the central motor conduction time was 9.5±1.76 ms vs 10.1±1.56 ms in patients without neuropathy. The excitability of the motor pathways was studied by paired transcranial magnetic stimulation at interstimulation intervals of 30–1000 ms. In normal control subjects, an early facilitation of the amplitude of the compound muscle action potential at an interstimulation interval of 30 ms was found, while no facilitation was present in diabetic patients. In addition the compound muscle action potential latencies were prolonged at interstimulation intervals of 30–50 ms in diabetic patients. The changes of excitability did not correlate with the presence of peripheral neuropathy, metabolic control or diabetes duration. It is concluded that long-term normoalbuminuric IDDM patients have impaired excitability but normal central conduction time of the motor pathways.Abbreviations CMCT Central motor conduction time - CMAP compound muscle action potential - ISI interstimulation interval - MNCV motor nerve conduction velocity - SNCV sensory nerve conduction velocity - APB abductor pollicis brevis muscle - IDDM insulin-dependent diabetes mellitus - NIDDM non-insulin-dependent diabetes mellitus     

糖尿病周围神经病变神经传导速度、F波及皮肤交感反应的变化及临床意义

目的 探讨糖尿病周围神经病变（DPN）患者神经传导速度（NCV）、F波及交感神经皮肤反应（SSR）的变化特点及临床应用价值.方法 97例DPN患者进行神经电生理检查,包括运动神经传导速度（MCV）、感觉神经传导速度（SCV）、F波及SSR检测.结果 异常率分别为SSR 75.2％,NCV 48.8％,F波34.5％,下肢神经病变重于上肢（P＜0.05）.结论 NCV、F波及SSR联合应用可全面地评估糖尿病周围神经的损害,三者相辅相成,缺一不可.     

Median neuropathy at the wrist as an early manifestation of diabetic neuropathy

Aims/Introduction

To elucidate the clinical significance of median neuropathy at the wrist (MN) in patients with diabetes.

Materials and Methods

In total, 340 patients with diabetes who were hospitalized for glycemic control were enrolled in the present study. The diagnoses of MN and diabetic polyneuropathy (DPN) were based on electrophysiological criteria. A total of 187 patients were divided into four subgroups: patients without MN or DPN; patients with MN without DPN; patients with MN and DPN; and patients with DPN without MN. Intergroup comparisons of clinical characteristics and results of nerve conduction studies were carried out.

Results

A total of 71 patients had neither MN nor DPN; 25 had MN, but no DPN; 55 had MN and DPN; and 36 had DPN, but no MN. In comparison with the MN and DPN group, the MN without DPN group included more patients in the early phase of diabetes (diagnosed within the past 5 years) and fewer patients with diabetic microangiopathy. Comparative median nerve conduction studies showed significantly lower motor and sensory nerve conduction velocities, longer F-wave latencies, and smaller sensory nerve action potentials in patients with MN and DPN than in those without DPN.

Conclusions

MN in patients with diabetes could be attributed to an impairment in axonal function at common entrapment sites, and could be used to identify an early manifestation of diabetic neuropathy.     

糖尿病周围神经病700例临床与神经电生理分析

目的探讨糖尿病周围神经病的临床和电生理特点,明确电生理检查的诊断价值。方法对700患者进行感觉和运动神经传导测定,240例患者进行针极肌电图测定。结果507例(724%)患者电生理检查异常,其中307例(606%)为多发性周围神经病,74例(146%)为腕管综合征;感觉神经传导异常程度重于运动神经,波幅的下降程度较传导速度减慢明显,下肢重于上肢(P<005)。仅有46%的患者针极肌电图异常而神经传导正常。结论糖尿病周围神经病的临床和电生理表现均以感觉神经受损为主;电生理检查有助于发现临床病变,但并非所有患者均能发现电生理异常;建议不将针极肌电图进行糖尿病周围神经病的筛查作为常规使用。     

The significance of carpal tunnel syndrome in transthyretin Val30Met familial amyloid polyneuropathy

Carpal tunnel syndrome (CTS) is frequently reported in association with amyloidosis. We determined the significance of CTS in transthyretin Val30Met-associated familial amyloid polyneuropathy (FAP ATTR Val30Met) by comparing the electrophysiological indices of the median and ulnar nerves in 58 patients. As a whole, sensory nerve conduction velocity (SCV) was slowed and distal motor latency (DML) was prolonged to a similar extent in the median and ulnar nerves in these patients. The extent of abnormalities in the median nerve was almost similar to that in the ulnar nerve in both early-onset cases from endemic foci and late-onset cases from non-endemic areas. In age-matched idiopathic patients with CTS (20 patients, 27 hands), the slowing of SCV and the prolongation of DML in the median nerve were significant, while the slowing of motor conduction velocity was much less compared to FAP ATTR Val30Met patients. Although concomitant lesions in the ulnar nerve entrapment site at the wrist cannot be excluded, these findings indicate that CTS is not the sole distinctive feature in the majority of FAP ATTR Val30Met patients. The electrophysiological abnormality at the distal portion of the median nerve may be a consequence of polyneuropathy rather than an entrapment injury.     

The electrophysiological findings of subclinical neuropathy in patients with recently diagnosed type 1 diabetes mellitus

To assess the prevalence of subclinical neuropathy within the first year of type 1 diabetes mellitus, 30 patients and 14 healthy subjects have been studied prospectively. The patients whose diabetes duration was longer than 1 year have been excluded from the study. Control group consisted of healthy volunteers. Subjective neuropathy symptoms, neurological examination, and electrophysiological findings were evaluated. All patients were clinically asymptomatic. At least two abnormal independent neurophysiological nerve parameters, which were required as the criterion of the peripheral nervous system subclinical involvement, were found as in 96.6% of diabetic patients in the first years. The percentages of abnormal electrophysiological parameters in different motor and sensory nerves were 86.7% in sural nerve, 83.3% in peroneal motor nerve, 73.3% in posterior tibial motor nerve, 66.7% in median motor nerve, 63.3% in ulnar motor nerve, 60% in median sensory nerve, and 46.7% in ulnar sensory nerve. While distal motor latency, F conduction time, and minimum F latency were the most frequent abnormal parameters in the upper extremity electrophysiological study; conduction velocity, minimum and mean F latencies, F conduction time were the most frequent abnormal parameters in the lower extremity. In all sensory nerve conduction studies, the most frequent abnormal parameter was the onset latency. In the autonomic sympathetic nerve electrophysiological study, plantar SSR latency was found significantly longer than the control group. In the lower extremity generally somatic motor fibres, sensory large fibres and sympathetic autonomic nerve fibres were found to be more affected. There is a correlation between HbA1c levels and nerve conduction velocity in posterior tibial and peroneal nerves. However, upper extremity nerve conduction dysfunction was not correlated with HbA1c value. Neither the duration of disease nor the age of the subject correlated with the nerve dysfunction.     

Femoral versus peroneal neuropathy in diabetic children and adolescents--relationships to clinical status, metabolic control and retinopathy

In order to estimate the prevalence of diabetic neuropathy in proximal and distal peripheral nerves, femoral and peroneal motor conduction was evaluated in 61 diabetic children, adolescents and young adults whose type 1 diabetes had become clinically apparent before the age of 14 years. Femoral motor nerve conduction velocity (FMNCV) in diabetic patients (63.8 +/- 10.4 m/sec) was not significantly different from FMNCV in control subjects (65.6 +/- 7.1 m/sec). By contrast, peroneal motor nerve conduction velocity (PMNCV) in diabetic patients (50.2 +/- 6.9 m/sec) was significantly lower than in controls (54.1 +/- 3.5 m/sec). Distal motor weakness, sensory deficit and absent Achilles reflexes were strongly correlated to impaired motor conduction in peroneal and also in femoral nerve. Peroneal nerve abnormality was negatively correlated with HbA1 levels, while femoral nerve abnormality was positively correlated with the presence of retinopathy. This discrepancy is not fully understood. Age and duration of diabetes were unrelated to femoral or peroneal motor nerve conduction velocity. Our data emphasize the frequent occurrence of subclinical proximal neuropathy in diabetic children and adolescents.     

Nerve conduction velocity study of the upper limb in Raynaud's phenomenon

A prospective study of upper limb nerve conduction velocity was performed in 39 subjects (9 males, 30 females, mean age 46.8 years) with idiopathic Raynaud's phenomenon (RP) and 18 patients (3 males, 15 females, mean age 49.9 years) with RP secondary to systemic sclerosis (SS). Five subjects with idiopathic RP (13%) showed slowing of sensory conduction velocity (SCV) of the distal median nerve, associated with delayed distal motor latency (DML) of the same nerve in three patients, without clinical signs or symptoms of carpal tunnel syndrome (CTS). Three patients with secondary RP (17%) had reduction of SCV of the distal median nerve, associated with increased DML of the same nerve in one and with clinically silent slowing of SCV of the ulnar nerve in two (11%). Mean distal SCVs of the median nerve were significantly lower and mean DMLs were significantly higher in both groups with respect to a control group. Mean distal conduction of the ulnar nerve was significantly slower only in the group with secondary RP. No slowing was observed in the proximal part of any nerve. It seems likely that patients with idiopathic RP have slowing of conduction in the distal part of the median nerve, along the carpal tunnel. Since slowing does not occur in all parts of the nerves of the hand, it cannot be related to acral vasomotor disturbances, but to local or systemic factors. In contrast, patients with secondary RP had slowing of median and ulnar nerve conduction velocity, presumably related to subclinical distal peripheral neuropathy. A nerve conduction study of the hand could be useful in cases of suspected secondary origin of RP. In idiopathic RP, slowing of conduction may only affect the median nerve, whereas in secondary RP it may affect other nerves of the hand. Received: 13 October 1999 / Accepted: 6 March 2000     

Elevated von Willebrand factor antigen predicts deterioration in diabetic peripheral nerve function

Summary We have studied the temporal relationship of plasma von Willebrand Factor (vWF), a marker of endothelial damage, with the development of complications in 63 young diabetic patients (56 of whom were insulin-dependent) who took part in a prospective study. Results are presented from baseline to follow-up. In the group as a whole, no significant changes were found in any autonomic function tests, temperature discrimination threshold or nerve conduction velocities. Median motor and peroneal latency were significantly increased, while median motor, peroneal motor and sural sensory potentials were significantly decreased at follow-up compared with baseline (p<0.001). There was a significant fall in mean plasma vWF antigen and ristocetin co-factor activity in the entire group. Within the group, we identified eight patients whose peroneal motor and sural sensory conduction velocities had decreased by over 2 ms^–1. In these patients (Group A), baseline vWF antigen and activity were significantly higher than in the rest of the patients (Group B), (p=0.04) and vWF antigen was still significantly higher after 3 years (p=0.02). There were no differences between the groups in incidence of retinopathy, urinary albumin excretion rate or macrovascular disease. To assess the influence of glycaemic control on vWF, we first compared a matched group (C) of diabetic patients with similar HbA₁ to that of group A, but with normal nerve conduction velocities: vWF was still significantly higher in group A compared with group C (p=0.02). Furthermore, hierarchical regression showed that vWF predicted deteriorating nerve function independently of glycaemic control or the type of diabetes. Endothelial dysfunction may be associated with development of peripheral neuropathy in young diabetic patients.Abbreviations Standardized regression coefficient - B unstandardized regression coefficient - IQR inter-quartile ranges - MMCV median motor nerve conduction velocity - MSCV median sensory nerve conduction velocity - PMCV peroneal motor nerve conduction velocity - SSCV sural sensory nerve conduction velocity - UAER urinary albumin excretion rate - vWF von Willebrand factor - vWFact von Willebrand factor activity - vWFag von Willebrand factor antigen - IDDM insulin-dependent diabetes mellitus - NIDDM non-insulin-dependent diabetes mellitus     

Prevalence of peripheral neuropathy and associated risk factors in children with type 1 diabetes

AimTo detect the prevalence of diabetic polyneuropathy (DPN) in children with type 1 diabetes (T1D) and to identify associated the risk factors.MethodsThis cross-sectional study evaluated children aged between 2 and 16y with T1D for ≥2 y. Detailed neurological examination, neuropathy symptom score, and nerve conduction studies were done in all children to assess nerve dysfunction. Disease-related factors were evaluated for the prediction of neuropathy.ResultsSixty-six children (67% boys) were enrolled. The mean age at the time of diagnosis of T1D was 7.1 ± 2.6 years. The mean duration of diabetes was 4 ± 1.8 years. None of the patients had neuropathy on clinical examination or on the neuropathy symptom score. The prevalence of subclinical DPN was 18.2% (n = 12/66). The type of neuropathy was pure motor (n = 11, 91.6%) and mixed sensorimotor (n = 1, 8.3%). The common peroneal nerve was most commonly affected (n = 6, 50%), followed by the tibial (n = 4, 33.3%) nerve. The most common patterns of nerve involvement were mixed axonal and demyelination (n = 7, 58.3%), followed by axonal (n = 3, 25%) and demyelinating type (n = 2, 16.6%). Children with subclinical DPN had a significant reduction in velocity of tibial, common peroneal, median motor, and ulnar motor nerves; delayed latency in common peroneal, median motor, ulnar motor, and median sensory nerves compared to those without DPN (p value <0.05). A higher body mass index predicted the development of subclinical DPN (p value <0.05).ConclusionNearly one-fifth of children with T1D have subclinical neuropathy as early as two years of the disease. A higher body mass index is significantly associated with DPN. Electrophysiological studies should be performed regularly to screen for nerve dysfunction and its progression.     

Peripheral nerve abnormalities in newly-diagnosed diabetic children

Summary The prevalence of clinical and subclinical peripheral neuropathy was evaluated in 51 unselected children at the time of onset of type I diabetes. Twenty-eight patients were followed for one year in order to establish the influence of metabolic control on peripheral nerve function. Twenty-two % of the diabetic children showed nerve conduction abnormalities at the onset and 11.7% had clinical features of peripheral neuropathy. After one year of disease, these figures had changed to 14.3% and 7.1%. Five of 7 children with altered electrophysiological tests in the baseline assessment had had normalization of all parameters one year later. No correlations between insulin requirement and nerve conduction were found. The M value was significantly correlated only with median sensory conduction velocity (p<0.005). Significant correlations were demonstrated between HbA₁ concentration and both peroneal motor conduction velocity (p<0.025) and median sensory conduction velocity (p<0.005); these correlations were still present after one year of disease. In the first period of diabetic disease there is functional rather than structural damage of the nerves. The pathogenetic role of hyperglycemia is confirmed; however individual susceptibility to nerve dysfunction may play an important role in the nerve impairment in diabetes. This study was supported by the C.N.R. Project ‘Preventive and Rehabilitative Medicine’, Subproject ‘Degenerative Diseases of the Nervous System’; Project N. 84.02472.56.115.10324.     

Nerve conduction abnormalities in untreated maturity-onset diabetes: relation to levels of fasting plasma glucose and glycosylated hemoglobin.

The role of metabolic abnormalities in the development of diabetic neuropathy is controversial. To investigate the influence of hyperglycemia on nerve conduction, we studied 20 untreated maturity-onset diabetic patients and 23 normal control subjects of similar age. Nerve conduction velocity of motor (median, peroneal, and tibial) and sensory (median and sural) nerves in diabetic patients was significantly slowed and H-reflex latency time prolonged. Levels of fasting plasma glucose in diabetic subjects were correlated with slowed motor conduction velocity of the median, peroneal, and tibial nerves but not with sensory nerve conduction velocities. Levels of glycosylated hemoglobin, an index of long-term glycemia, were correlated with slowing of peroneal motor conduction velocity in diabetic patients. These associations could not be explained by patient age or duration of diabetes. These findings suggest that the degree of hyperglycemia of untreated maturity-onset diabetes contributes to the motor nerve conduction abnormalities in this disease.     

Diabetic neuropathy and plasma glucose control

Diabetic neuropathy is defined, and theories of its pathogenesis are reviewed. Recent studies designed to investigate the influence of plasma glucose on nerve function in noninsulin-dependent diabetic patients are summarized. Motor nerve conduction velocities in the median and peroneal nerves were measured using a double-stimulus technique, and sensory conduction velocity was measured by conventional methods before and after therapy with oral agents or insulin. The degree of hyperglycemia was assessed by measurement of fasting plasma glucose and glycosylated hemoglobin concentrations. The degree of slowing in motor nerve conduction velocity in untreated patients was found to correlate with the fasting plasma glucose and glycosylated hemoglobin concentrations, but sensory nerve function, although abnormal, did not show such correlation. Reduction of hyperglycemia was associated with improvement in motor nerve conduction velocity in the peroneal and median motor nerves of these patients, but sensory nerve conduction velocity showed no such improvement. Improvement in median motor nerve conduction velocity was directly related to the degree of reduction in fasting plasma glucose concentration. These findings suggest that metabolic factors related to hyperglycemia are important in the impaired motor nerve function seen in noninsulin-dependent patients with maturity-onset diabetes.     

Neurophysiological study of the effect of combined kidney and pancreas transplantation on diabetic neuropathy: a 2-year follow-up evaluation

Previous study have reported a significant improvement of peripheral neuropathy following combined pancreas and kidney transplantation attributed to improvement of blood glucose control by some authors and to elimination of uraemia by others. To asses the specific role of uraemia and hyperglycaemia in neuropathy, 16 diabetic uraemic patients with combined pancreas and kidney transplantation were compared to 9 diabetic patients with a renal graft only. Neurophysiological studies of peripheral neuropathy included ulnar and deep peroneal nerve motor conduction velocity, median and sural nerve sensory conduction velocity were performed at baseline and 1 and 2 years after transplantation. One year after transplantation mean nerve conduction velocity significantly improved in both groups. However, changes were statistically significant in the kidney-pancreas group only. At the 2 year follow-up nerve conduction velocity had increased further in the pancreas-kidney group only. These data suggest that improvement of nerve conduction velocity following pancreas and kidney transplantation is predominantly due to the long-term euglycaemic state.     

Nerve conduction tests in patients with fibromyalgia: comparison with normal controls

The purpose of this study was to evaluate nerve conduction in fibromyalgia (FM) patients and normal subjects. Testing of F waves and motor, sensory, and mixed nerve conduction was performed in 33 consecutive female FM patients complaining of paresthesias in the extremities and in 17 age- and sex-matched healthy volunteers. The nerve conduction results in FM patients were no different from those of normal subjects except for prolonged peroneal distal motor latency ( P=0.048) and decreased peroneal motor conduction velocity ( P=0.030). Five of the 33 patients (15%) showed abnormalities in peroneal nerve conduction, five (15%) had carpal tunnel syndrome (CTS), and overall nine (27%) had electrophysiologic findings of focal entrapment, which indicated that focal neuropathies were common in this patient group. There was no evidence of generalized polyneuropathy in the FM patients.     

Glycemic control is related to the severity of impaired thermal sensations in type 2 diabetes

BACKGROUND: Small-fibre sensory neuropathy of diabetes presenting as impaired thermal sensations is associated with ominous consequences, such as foot ulcer and amputation, but there is a lack of systematic studies on its occurrence in large cohorts. We investigated (1) the impact of glycemic control on thermal thresholds, (2) the frequencies and patterns of sensory deficits, and (3) the contribution of sensory nerve abnormalities to neuropathic symptoms. METHODS: Quantitative sensory testing and nerve conduction studies were performed to measure warm and cold thresholds of extremities, and amplitudes of nerve action potentials on 498 type 2 diabetic patients and 434 control subjects with similar age and gender distributions, enrolled during the same period. RESULTS: The diabetic patients had higher thermal thresholds than control subjects (p < 0.0001). Thermal thresholds of the lower and upper extremities were linearly correlated with HbA1C on multiple linear regression analysis (p < 0.01). By the multivariate logistic regression analysis, HbA(1C) and age were the most important risk factors independently associated with elevated thermal thresholds (p < 0.01). Elevated warm threshold in the big toe was the most frequent abnormality (60.2%) compared to abnormal cold threshold in the big toe (39.6%) and abnormal sural nerves on nerve conduction studies (12.9%). Elevated thermal thresholds were risk factors for neuropathic symptoms independent of HbA(1C). CONCLUSION: Small-fibre neuropathy with the impairment of thermal sensations is the most frequent sensory deficit in diabetes, and HbA1C is significantly associated with the elevated thermal thresholds.     

2型糖尿病患者高血压与糖尿病性神经病变的关系

目的 探讨2型糖尿病患者高血压与糖尿病性神经病变的关系。方法 利用心自主神经功能检测系统和神经电生理检测仪对107例（高血压组52例,非高血压组55例）2型糖尿病患者的心自主神经功能和肢体的末梢神经传导速度、皮肤痛温觉、振动沉进行测定,以判断心自主神经病变和末梢神经病变。结果 两组间末梢神经功能和心自主神经功能各指标除心的是距频谱分析的高频值外差异均无显著性（P＜0.05）。Logistic回归分析显示高血压与心自主神经病变显著相关（P＜0.01）,而与末梢神经病变无显著相关。结论 2型糖尿病患者高血压是心自主神经病变发病的危险因素,而与末梢神经病变无明显关系。     

α-硫辛酸治疗2型糖尿病周围神经病变的临床研究

目的观察旷硫辛酸（ALA）治疗糖尿病周围神经病变（DPN）的临床疗效。方法将120例DPN患者随机分为2组,对照组60例予甲钻胺静滴治疗,治疗组60例予ALA静滴治疗,疗程2周。观察两组治疗前后临床症状、体征、FBG、HbA1c、血浆内皮素（ET）、尿白蛋白（uAIb）和C反应蛋白（C-RP）水平变化,以及运动神经传导速度（MNCV）、感觉神经传导速度（SNCV）。结果治疗组治疗后MNCV、SNCV上升作用与对照组相仿,而血ET、血C-RP、UAlb均下降,疗效明显优于对照组,差异均有统计学意义。结论ALA治疗DPN临床疗效明显优于甲钴胺。