Early diagnosis of prediabetic peripheral neuropathy depends on the evaluation of small fibers.Traditional nerve conduction tests can only evaluate the function of large myelinated fibers,while lack of sensitivity to small fibrous lesions.These lesions were related to pain and autonomic neuropathy.In recent years,with the progress of neurophysiological diagnosis technology,the early diagnosis of diabetic peripheral neuropathy has been improved.Clinical methods,commonly used in the detection of small fibrous lesions,mainly include skin sympathetic response,quantitative sensory test,contact heat pain evoked potential,and quantitative sudomotor axonal reflex test.In this paper,the pathogenesis of diabetic peripheral neuropathy,neurological pathological changes and applications of electrophysiology technology were reviewed to provide an objective basis for early diagnosis of prediabetic peripheral neuropathy.

BACKGROUND:Danhong injection, scavenging free radicals and inhibiting lipid peroxidation, can improve microenvironment injury after cerebral infarction. OBJECTIVE:To explore the influence of bone marrow mesenchymal stem cel s combined with Danhong injection on expression of GAP-43 and Bcl-2 after cerebral infarction in rats. METHODS:Sixty Wistar rats were selected to prepare models of cerebral infarction by middle cerebral artery occlusion and then randomly divided into control group, bone marrow mesenchymal stem cel group, and combination group. Control group received tail vein injection of PBS. Bone marrow mesenchymal stem cel group received tail vein injection of 2.5×109/L bone marrow mesenchymal stem cel suspension. Combination group received injection of 2.5× 109/L bone marrow mesenchymal stem cel suspension+2 mL/kg Danhong injection, for 5 consecutive days, once a day. RESULTS AND CONCLUSION:There were no significant differences in the neurological dysfunction scores among the three groups at 24 hour and 3 days after implantation (P>0.05). The neurological dysfunction scores in the ombination group were significantly lower than those in the bone marrow mesenchymal stem cel group and control group at 1 and 2 weeks after transplantation (P<0.05). In the combination group, GAP-43 and Bcl-2 expression was significantly higher than the bone marrow mesenchymal stem cel group and control group (P<0.05). Bone marrow mesenchymal stem cel transplantation combined with Danhong injection can significantly promote the local expression of GAP-43 and Bcl-2 after cerebral infarction, and has obvious inhibitory effects on cel apoptosis in rats with cerebral infarction.

Objective To investigate the correlation between plasma homocysteine level and impaired glucose tolerance(IGT) patients in peripheral neuropathy.Methods 80 patients with IGT were selected according to the results of routine nerve conduction test,including 40 patients associated with peripheral neuropathy (IGT-PN),and 40 patients without peripheral neuropathy (IGT-NPN).Besides,40 healthy subjects were selected as control.Plasma homocysteine levels were measured in the three groups by enzyme rate method.The severity of neuropathy was scored and graded by the Toronto Clinical Scoring System (TCSS).Results Plasma homocysteine levels were significantly higher in the all IGT groups than those in the control group.The plasma homocysteine level in the IGT-PN group (14.2±2.7) μmol/L was significantly higher than that in the IGT-NPN group (12.3±2.6) μmol/L (P＜0.05).Regression analysis showed that plasma homocysteine level had independent effects on IGT with peripheral neuropathy.Plasma homocysteine level was positively correlated with TCSS score.Conclusions Plasma homocysteine may play an important role in the pathogenesis of peripheral neuropathy in patients with IGT,and their level may be associated with the severity of peripheral neuropathy.

Objective To study the roles of the contact heat evoked potential (CHEP) in evaluating the small nerve fibers of cranial and spinal in elderly diabetic patients,and to analyze the feature of the small fibers in order to provide scientific foundations for early diagnosis of diabetic neuropathy (DN).Methods Totally 50 diabetic patients and 40 healthy subjects were included in this study.The diabetic patients were divided into the normal nerve conduction group (n=17) and the abnormal nerve conduction group (n=33).CHEP was determined and thermal stimuli was given to the area of eyelid,forearm and peroneal.Sensory and motor nerve conduction velocity in the upper and lower limbs were tested in all diabetic patients.Results Compared with the healthy group,the N wave latencies were prolonged and the N-P amplitudes were reduced in the area of eyelid,forearm and peroneal in diabetic patients (all P＜0.01).Compared with the healthy group,the logarithm of N-P amplitudes were reduced in areas of forearm and peroneal [(1.70±0.10) vs.(1.60±0.14),(1.65±0.078) vs.(1.54±0.15),both P＜0.05] and N wave latencies were prolonged in eyelid area [(343.1±18.2) ms vs.(385.4±26.5) ms,P＜0.05] in normal nerve conduction group.Compared to group with normal nerve conduction velocity,the logarithm of N-P amplitudes was reduced in peroneal area [(1.54±0.15) vs.(1.44±0.15),P＜0.05] in abnormal nerve conduction group.Conclusions CHEP can detect the early impairment of the small fibers in elderly diabetic patients.The early smallfiber impairments in diabetic neuropathy may be axon-oriented in spinal nerves and myelin-oriented in cranial nerves.

Objective To evaluate the effect of the plasma homocystine (Hcy) after methionine loading test (MLT) on the recurrence of ischemic vascular event,including cerebral infarction,transient ischemic attack (TIA),acute coronary syndrome,other vascularembolism,in cerebral infarction patients.Methods The fasting plasma homocystine (FHcy) and homocystine after MLT (PHcy) levels were measured by high-performance liquid chromatography.383 cerebral infarction patients with normal Hcy level were selected and divided into hyperhomocysteinemia after MLT (PHcy) group (n=135) and non-hyperhomocysteinemia after MLT (NPHcy) (n=248).Recurrence rates of ischemic vascular events within a 5-years follow-up period was observed.Results The levels of FHcy,PHcy and △Hcy (PHcy level subtracted FHcy level) were higher in males than in females in the two groups (all P＜0.05).The recurrence rates of cerebral infarction/TIA,acute coronary syndrome and other vascular embolism events were higher in PHcy group than in NPHcy group within the follow-up period (all P＜0.05).By forward stepwise logistic analysis,we found that the increased PHcy and △Hcy levels were the independent risk factors for recurrent ischemic vascular events [odds ratio (OR):0.509,2.107,95％ confidence interval (CI):0.286-0.904,1.185-3.745,both P＜0.05].Conclusions PHHcy may be an independent risk factor for recurrence ischemic vascular events in cerebral infarction.

Objective To investigate whether vitamin B complex supplements would reduce stroke-related disabili-ty in hyperhomocysteinemia (Hhcy) patients with recent ischemic stroke. Methods One thousand patients with brain infarc-tion and Hhcy were assigned to receive either a daily dose of vitamin B complex (treatment group, n=500) or not (control group, n=500) on the base of conventional secondary prevention medications for a period of 2 years. The neurological dys-function was assessed by National Institutes of Health Stroke Scale (NIHSS) and stroke disability was evaluated by Barthel Index (BI) score. High performance liquid chromatographic method with fluorescence detection was used for the determina-tion of total plasma homocysteine levels. After 2 years of follow-up, the patients in the treatment group, whose tHcy level was reduced by 3-μmol/L or more, was defined as the treatment subgroup. Results The homocysteine levels were significantly reduced after 3, 12 and 24-month treatment than those of control group (P＜0.05). A lower NIHSS scale was found at 12, 18 and 24-month in treatment group compared with that in control group (P＜0.05), no significant differences at other time points between two groups (P>0.05). For the BI score, there were no significant differences at any time points between two groups (P>0.05). After 2 years of vitamin B complex supplementation, there were lower NIHSS scale and higher BI scale in treatment subgroup than those of control group (P＜0.05). Conclusion The lower level of tHcy induced by vitamin B inter-vention may be beneficial to the improvement of neurological deficit in patients with ischemic stroke.

Objective To study the value of methionine loading test (MLT) in the mild vascular cognitive impairment (VCI) after acute cerebral infarction.Methods The fasting plasma homocystine (Hcy) level and homocystine level after MLT were measured by high-performance liquid chromatography methods.We chose 240 patients with normal level of fasting plasma Hcy (normal group),159 patients with normal level of Hcy after MLT,81 patients with hyperhomocysteinemia after MLT (hyperhomocysteinemia group),and 112 patients with fasting hyperhomocysteinemia (fasting hyperhomocysteinemia group) in this study.The Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) were conducted in normal,hyperhomocysteinemia and fasting hyperhomocysteinemia groups on admission,at 7d,14 d,30 d after treatment.Results Logistic regression analysis showed that the increased level of Hcy might be an independent risk factor for VCI [OR:1.285,95％CI:1.038-1.265,P＜0.05].The scores of MMSE and MoCA were lower in patients with fasting hyperhomocysteinemia and patients with hyperhomocysteinemia after MLT than in patients with normal fasting plasma Hcy at 7 d,14 d and 30 d after treatment (P＜0.01 or 0.05),while the scores had no significant differences among the three group on admission (P＞0.05).There were no significant differences in MMSE and MoCA scores between patients with fasting hyperhomocysteinemia and patients with hyperhomocysteinemia after MLT on admission,7 d,14 d and 30 d after treatment (P＞0.05).Conclusions Hcy may be an independent risk factor for VCI.The MLT can discover the dormant vascular risk factors for VCI,which offers a valuable detection method for early intervention and prevention in the clinical medicine.

Objective To evaluate the impairment of ulnar nerve and its relationship with sensory symptoms in the ulnar territory in patients with carpal tunnel syndrome (CTS) through electrophysiological approach.Methods We retrospectively reviewed 55 cases with CTS admitted in our hospital from January 2012 to February 2013.Patients with CTS were graded as mild-moderate (35 cases) and severe (20 cases) according to Stevens standard and were divided into symptomatic and non-symptomatic group according to the presence of sensory symptom in little finger region.Twenty healthy volunteers were included as control.Median and ulnar nerves electrophysiological study were performed using the Keypoint.net (Medoc Ltd) electromyogram device.Results Finger 5-wrist sensory conduction velocities (SCVs) of ulnar nerve were reduced ((51.71 ± 2.93) m/s vs (58.62 ± 3.21) m/s,t =8.80,P ＜ 0.01) in CTS group,compared with control group.But the sensory nerve action potential (SNAP) amplitudes had no difference.Pearson correlation analysis showed that finger 5-wrist SCVs and the SNAP amplitudes of ulnar nerve were negatively correlated with the distal motor latency of the median nerve,while positively correlated with the compound muscle action potential amplitudes,finger 1-wrist,finger 3-wrist SCVs and SNAP amplitudes of median nerve,in mild-moderate group,finger 5-wrist SCVs of ulnar nerve were slowed and the SNAP amplitudes were reduced ((51.59 ±2.70) m/s vs (53.72 ±2.58) m/s; (13.51 ± 1.84) μV vs (15.21 ±2.16) μV,t =2.24,2.30,P ＜ 0.05 respectively) in the symptomatic group,compared with the non-symptomatic group.However,in severe group,only 2 cases had sensory symptom in little finger region.Conclusions CTS patients may have impairments due to ulnar nerve entrapments at wrist,which aggravate with disease progression.Sensory symptoms in ulnar territory are more frequent during the mild-moderate stage,and may relate with ulnar nerve involvement.

Objective To evaluate the function status of motor nerve in patients with carpal tunnel syndrome ( CTS) sensory neuropathy by single-fiber conduction studies ( SF-CS).Methods Forty patients with CTS were divided into two groups according to the nerve conduction abnormality of median nerve .The sensory conduction abnormalities ( SCA) group included 20 patients with abnormal sensory conduction , while the sensory motor conduction abnormalities ( SMCA) group included 20 patients with abnormal motor sensory conduction.The Keypoint.net electromyogram device was used to detect the wrist to the abductor pollicis brevis latency , using the saddle shaped stimulating electrodes for stimulating and the single fiber electromyography electrode for recording.The control group included 20 healthy people.Results The latency of single-fiber conduction of median nerve in SCA group , SMCA group and control group was (3.92 ±0.28) ms, (4.71 ±0.49) ms and (3.41 ±0.31) ms (F=63.829, P=0.000), respectively.The area under the receiver operating characteristic curve was 0.920 for the latency of single-fiber conduction of median nerve , and its specificity was 85%in cut off point.Conclusions There is clinical motor nerve damage in patients with CTS sensory neuropathy.The SF-CS may become an effective means for early evaluation of motor nerve function state.

BACKGROUND: Hyperhomocysteinemia is a new independent risk factor for coronary heart disease (CHD), but its association with cerebrovascular diseases is still controversial. The level of fasting plasma total homocysteine (plasma tHcy) alone is not enough to reveal the effect of hyperhomocysteinemia on cerebral infarction (CI).OBJECTIVE: To explore the association of hyperhomocysteinemia with folacin and vitamin B12 and with CI in young and middle-aged people, as well as the role of methionine loading test in the diagnosis of latent hyperhomocysteinemia.DESIGN: A case-control study, Spearman correlation analysis.PARTICIPANTS: A total of 85 patients were hospitalized within 2 days after the onset of CI at the Department of Neurology, the General Navy Hospital of Chinese PLA, from 2000 to 2003. There were 63 males and 22females aged 29-55 years old with the mean age of (48.74±5.05) years.There were 48 cases of lacunar CI and 37 cases of arterial thrombotic CI.Meanwhile, 44 normal controls, 30 males and 14 females aged 29-55 years old with the mean age of (47.75±6.71), were recruited from the department staff and those who came to the hospital for routine health examination.METHODS: Fasting vein blood of 6 mL was collected from the patients on the 1st day of hospitalization, and 2 mL of the blood was used for detecting the level of fasting plasma tHcy using high efficiency liquid chromatography. Methionine of 0.1 g/kg was taken orally by patients immediately after blood sampling; 4 hours later, the level of loading plasma tHcy was also determined. The remaining 4 mL was used for detecting the level of serum folacin and vitamine B12 with bioradiation assay.MAIN OUTCOME MEASURES: ① The level of fasting and loading plasma tHcy in CI group and control group. ② Incidence of hyperhomocysteinemia in CI group and control group [Hyperhomocysteinemia was confirmed if hyperhomocysteine was higher than 95% of the upper limit of fasting plasma tHcy or 4-hour loading plasma tHey of normal control group, that is, fasting plasma tHcy ＞17.26 μnol/L in males and ＞14.17 μnol/L in females; and loading plasma tHcy should be ＞ 44.57 μmol/L in males and ＞ 40.02 μmol/L in females. ③ The level of serum folacin and vitamine B12 in CI group and control group. ④ Single factor analysis of fasting plasma tHcy and related risk factors.RESULTS: Totally 85 CI patients and 44 normal controls were recruited in this study and all data were statistically analyzed. ① The level of fasting and loading plasma tHcy in CI group and control group: Both fasting and loading plasma tHcy was significantly higher in CI group than in control group [(22.49±9.80), (13.08±2.33) μmol/L; (48.07±11.20), (37.23±3.48)μmol/L, (t=8.409, 8.187, P ＜ 0.01)]. ② Incidence of hyperhomocysteinemia: The incidence was obviously higher in CI group than in control group [68% (58/85), (9%, 4/44), X2=40.628, P ＜ 0.01]. Totally 35 patients (41%, 35/85) had higher fasting plasma tHcy than that of normal controls, and 23 (27%, 23/85) had higher loading plasma tHcy than that of normal controls. ③ The level of serum folacin and vitamine B12 in CI group and control group: They were [(5.73±2.52), (7.14±2.20) μg/L] in CI group,significantly lower than control group [(473.47±190.19), (576.70±212.05) rng/L,(t =3.151, 2.809, P ＜ 0.01)]. ④ Single factor analysis of plasma tHcy with related risk factors: Fasting and loading plasma tHcy was found obviously associated with sex, and folacin and vitamine B12 level (r = -0.306 to 0.488, P ＜ 0.01), but not with other risk factors and neurological deficit scores (r = 0.021-0.173, P ＞ 0.05). Moreover, only plasma tHcy level was proved to have significant positive correlation with fasting blood glucose (r=0.186, P ＜ 0.05).CONCLUSION: Hyperhomooysteinemia is an independent risk factor for CI in young and middle-aged people. Methionine loading test is an essential means for detecting latent hyperhomocysteinemia. Insufficiency of folacin and vitamine B12, two important nutrition factors, may lead to hyperhomocysteinemia and indirectly result in CI.