Analysis of four hereditary protein C deficiencies associated with vascular thromboembolism.

OBJECTIVE: To analyze the clinical features and gene mutations in four families with hereditary protein C (PC) deficiency and explore their association with vascular thromboembolism. METHODS: The clinical data of four patients with PC deficiency were retrospectively analyzed. Venous blood samples were collected from the four affected patients and their family members, and relevant coagulation indexes and thrombin production and inhibition tests were performed. PCR was used to amplify and directly sequence the PROC gene of the probands. Software analysis was conducted to assess the conservativeness and pathogenicity of the mutated loci. Protein models were constructed to analyze the spatial structure before and after the mutation. RESULTS: Thrombin generation and inhibition assays demonstrated impaired anticoagulation in all four probands. Proband 1 and 4 presented clinically with pulmonary embolism and lower extremity deep vein thrombosis (DVT), Proband 2 with cerebral infarction, and Proband 3 with DVT. Genetic analysis revealed the presence of the following mutations: c.541T > G heterozygous missense mutation, c.577-579delAAG heterozygous deletion mutation, c.247-248insCT heterozygous insertion mutation, c.659G > A heterozygous missense mutation, and a new variant locus c.1146_1146delT heterozygous deletion mutation in the four probands, respectively. In particular, c.1146_1146delT heterozygous deletion mutations not reported previously. Conservativeness and pathogenicity analyses confirmed that most of these amino acid residues were conserved, and all the mutations were found to be pathogenic. Analysis of protein modeling revealed that these mutations induced structural alterations in the protein or led to the formation of truncated proteins. According to the American College of Medical Genetics and Genomics (ACMG) classification criteria and guidelines for genetic variants, c.1146_1146delT was rated as pathogenic (PVS1 + M2 + PM4 + PP1 + PP3 + PP4). CONCLUSION: The identified mutations are likely associated with decreased PC levels in each of the four families. The clinical manifestations of hereditary PC deficiency exhibit considerable diversity.

Catalpol alleviates hypoxia ischemia-induced brain damage by inhibiting ferroptosis through the PI3K/NRF2/system Xc-/GPX4 axis in neonatal rats.

Hypoxic-ischemic encephalopathy (HIE) is a brain damage caused by perinatal hypoxia and blood flow reduction. Severe HIE leads to death. Available treatments remain limited. Oxidative stress and nerve damage are major factors in brain injury caused by HIE. Catalpol, an iridoid glucoside found in the root of Rehmannia glutinosa, has antioxidant and neuroprotective effects. This study examined the neuroprotective effects of catalpol using a neonatal rat HIE model and found that catalpol might protect the brain through inhibiting neuronal ferroptosis and ameliorating oxidative stress. Behavior tests suggested that catalpol treatment improved functions of motor, learning, and memory abilities after hypoxic-ischemic injury. Catalpol treatment inhibited changes to several ferroptosis-related proteins, including p-PI3K, p-AKT, NRF2, GPX4, SLC7A11, SLC3A2, GCLC, and GSS in HIE neonatal rats. Catalpol also prevented changes to several ferroptosis-related proteins in PC12 cells after oxygen-glucose deprivation. The ferroptosis inducer erastin reversed the protective effects of catalpol both in vitro and in vivo. We concluded that catalpol protects against hypoxic-ischemic brain damage (HIBD) by inhibiting ferroptosis through the PI3K/NRF2/system Xc-/GPX4 axis.

Epigenome-wide DNA methylation analysis of myasthenia gravis.

Myasthenia gravis (MG) is a common neuromuscular junction disorder and autoimmune disease mediated by several antibodies. Several studies have shown that genetic factors play an important role in MG pathogenesis. To gain insight into the epigenetic factors affecting MG, we report here genome-scale DNA methylation profiles of MG. DNA was extracted from eight MG patients and four healthy controls for genome-wide DNA methylation analysis using the Illumina HumanMethylation 850K BeadChip. Verification of pyrosequencing was conducted based on differential methylation positions. Subsequently, C2C12 and HT22 cell lines (derived from mouse) were treated with demethylation drugs. Transcribed mRNA of the screened differential genes was detected using quantitative real-time PCR. The control and MG group were compared, and two key probe positions were selected. The corresponding genes were CAMK1D and CREB5 (P < 0.05). Similarly, the myasthenic crisis (MC) and non-MC group were compared and four key probe positions were selected. The corresponding genes were SAV1, STK3, YAP1, and WWTR1 (P < 0.05). Subsequently, pyrosequencing was performed for verification, revealing that hypomethylation of CAMK1D was significantly different between the MG and control group (P < 0.001). Moreover, transcription of CREB5, PKD, YAP1, and STK3 genes in the C2C12 cells was downregulated (P < 0.05) after drug treatment, but only YAP1 mRNA was downregulated in HT22 cells (P < 0.05). This is the first study to investigate genome-scale DNA methylation profiles of MG using 850 K BeadChip. The identified molecular markers of methylation may aid in the prevention, diagnosis, treatment, and prognosis of MG.

Analysis of cerebral infarction caused by dysplasminogenemia in three pedigrees.

Background and aims: Dysplasminogenemia is a rare heritable disease caused by plasminogen (PLG) gene defects resulting in hypercoagulability. In this report we describe three notable cases of cerebral infarction (CI) complicated with dysplasminogenemia in young patients. Methods: Coagulation indices were examined on STAGO STA-R-MAX analyzer. PLG: A was analyzed using a chromogenic substrate-based approach using a chromogenic substrate method. All nineteen exons of PLG gene and their 5'and 3'flanking regions were amplified by Polymerase chain reaction (PCR). Suspected mutation was confirmed by reverse sequencing. Results: PLG activity (PLG:A) in proband 1 and 3 of his tested family members, proband 2 and 2 of his tested family members, and proband 3 and her father were all reduced to roughly 50% of normal levels. Sequencing led to the identification of a heterozygous c.1858G>A missense mutation in exon 15 of the PLG gene in these three patients and affected family members. Conclusion: We conclude that the observed reduction in PLG:A was the result of this p.Ala620Thr missense mutation in the PLG gene. The CI incidence in these probands may be attributable to the inhibition of normal fibrinolytic activity as a consequence of this heterozygous mutation.

Association between malnutrition risk and hemorrhagic transformation in patients with acute ischemic stroke.

Background and aims: Malnutrition is a prevalent problem occurring in different diseases. Hemorrhagic transformation (HT) is a severe complication of acute ischemic stroke (AIS). Few studies have evaluated the association between malnutrition risk and hemorrhagic transformation in patients with acute stroke. We aim to investigate the influence of malnutrition risk on the risk of hemorrhagic transformation in patients with AIS. Methods: A total of 182 consecutive adults with HT and 182 age- and sex-matched patients with stroke were enrolled in this study. The controlling nutritional status (CONUT) score was calculated to evaluate the malnutrition risk. HT was detected by follow-up imaging assessment and was radiologically classified as hemorrhagic infarction type 1 or 2 or parenchymal hematoma type 1 or 2. Logistic regression models were conducted when participants were divided into different malnutrition risk groups according to the objective nutritional score to assess the risk for HT. Results: The prevalence of moderate to severe malnutrition risk in patients with AIS was 12.5%, according to the CONUT score. Univariate analysis showed that the CONUT score is significantly higher in patients with HT than those without HT. After adjusting for potential covariables, the patients with mild risk and moderate to severe malnutrition risk were associated with a higher risk of HT compared to the patients in the normal nutritional status group [odds ratio, 3.180 (95% CI, 1.139-8.874), P = 0.027; odds ratio, 3.960 (95% CI, 1.015-15.453), P = 0.048, respectively]. Conclusion: Malnutrition risk, measured by CONUT score, was significantly associated with an increased risk of hemorrhagic transformation in patients with AIS.

Parkinsonism-Hyperpyrexia Syndrome and Dyskinesia-Hyperpyrexia Syndrome in Parkinson's Disease: Two Cases and Literature Review.

Parkinsonism-hyperpyrexia syndrome (PHS) and dyskinesia-hyperpyrexia syndrome (DHS) are rare but exhibit life-threatening complications in Parkinson's disease (PD). We herein presented two cases of PD patients and performed a comprehensive and comparative literature review for these two syndromes. The first case was diagnosed as PHS with cerebral salt wasting syndrome caused by abrupt withdrawal of antiparkinsonian medication. Her symptoms were gradually remitted with reinstitution of the medication. The second one was an early-stage PD patient diagnosed as DHS in association with abuse of antiparkinsonian drugs. Her symptoms were gradually remitted with reduced dosage of dopaminergic drugs. Results of literature reviews revealed a total of 56 and 13 cases of PHS and DHS, respectively, and they were more likely to occur in elderly and long-term PD patients. These two syndromes showed different female-to-male ratio, similar mortality, and different recovery time. There were stark differences between PHS and DHS, including triggers (abrupt drug stoppage versus drug abuse), symptoms (worsened tremor and rigidity versus continuous dyskinesia), and treatment (drug reinstitution versus drug reduction). In summary, our reports and the review provide new insights into PHS and DHS in association with PD and may facilitate rapid discrimination of the syndromes for timely and proper treatment to reduce mortality.

A comparative analysis of 375 patients with lateral and medial medullary infarction.

BACKGROUND: Few studies have compared the etiology and clinical features between pure lateral medullary infarction (LMI) and pure medial medullary infarction (MMI). METHODS: All patients included were hospitalized at The First Affiliated Hospital and The Second Affiliated Hospital of Wenzhou Medical University from January 2015 to July 2020. Their risk factors, clinical manifestation, stroke mechanisms and short-term prognosis were analyzed retrospectively. RESULTS: Among the 387 patients enrolled, 266 (68.7%) had LMI, 109 (28.2%) had MMI, and 12 (3.1%) (nine men and three women) had LMI plus MMI. We analyzed the 375 patients of LMI and MMI. The average ages of LMI and MMI were 59.4 years and 62.69 years, respectively. Univariate analysis and multivariable logistic regression was used to investigate the existing risk factors of MMI relative to LMI. Prior infarction, poor glycemic control, and atherosclerosis were more frequently associated with MMI than with LMI. The clinical manifestation was significantly different between LMI and MMI. We used modified Rankin Scale (mRS) score as the short-term prognostic evaluation criteria, and MMI appeared worse than LMI. CONCLUSIONS: This study reveals that: (1) patients with MMI are older than those with LMI; (2) prior infarction, poor glycemic control, and atherosclerosis are independent risk factors of MMI than that of LMI; (3) the clinical manifestations of LMI and MMI are heterogeneous; (4) short-term prognosis of MMI is worse than LMI.

Differential and paradoxical roles of new-generation antidepressants in primary astrocytic inflammation.

BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are commonly used new-generation drugs for depression. Depressive symptoms are thought to be closely related to neuroinflammation. In this study, we used up-to-date protocols of culture and stimulation and aimed to understand how astrocytes respond to the antidepressants. METHODS: Primary astrocytes were isolated and cultured using neurobasal-based serum-free medium. The cells were treated with a cytokine mixture comprising complement component 1q, tumor necrosis factor α, and interleukin 1α with or without pretreatments of antidepressants. Cell viability, phenotypes, inflammatory responses, and the underlying mechanisms were analyzed. RESULTS: All the SSRIs, including paroxetine, fluoxetine, sertraline, citalopram, and fluvoxamine, show a visible cytotoxicity within the range of applied doses, and a paradoxical effect on astrocytic inflammatory responses as manifested by the promotion of inducible nitric oxide synthase (iNOS) and/or nitric oxide (NO) and the inhibition of interleukin 6 (IL-6) and/or interleukin 1ß (IL-1ß). The SNRI venlafaxine was the least toxic to astrocytes and inhibited the production of IL-6 and IL-1ß but with no impact on iNOS and NO. All the drugs had no regulation on the polarization of astrocytic A1 and A2 types. Mechanisms associated with the antidepressants in astrocytic inflammation route via inhibition of JNK1 activation and STAT3 basal activity. CONCLUSIONS: The study demonstrated that the antidepressants possess differential cytotoxicity to astrocytes and function differently, also paradoxically for the SSRIs, to astrocytic inflammation. Our results provide novel pieces into understanding the differential efficacy and tolerability of the antidepressants in treating patients in the context of astrocytes.

Correlation Study of Short-Term Mental Health in Patients Discharged After Coronavirus Disease 2019 (COVID-19) Infection without Comorbidities: A Prospective Study.

OBJECTIVE: The WHO has upgraded the status of coronavirus disease 2019 (COVID-19) from epidemic to global pandemic. The psychometric properties aspects of COVID-19 patients without comorbidities in the short term after discharge have not been reported. In this study, the Short Form 36 (SF-36) was used to evaluate the psychometric properties and to find relevant risk factors. METHODS: The study was conducted in seven hospitals from January 2020 to April 2020. The SF-36 questionnaire was administered one month after discharge. Univariate analysis and multivariate regression model were used to analyze the risk factors of psychometric properties impairment. RESULTS: In univariate analysis of independent risk factors, according to the comparison of whether the duration of positive nucleic acid was greater than 20 days, the positive nucleic acid duration was independently related to the decreased role-emotional value [100, IQR (66-100) vs 100, IQR (0, 100); p = 0.0156]. In addition, multivariable linear regression model showed that male sex and positive nucleic acid duration were related to decreased role-emotional value (p = 0.03< 0.05; p = 0.01< 0.05, respectively). Mental health was associated with age (p= 0.0435). Subsequently, we divided into three subgroups: less than seven days, 7 to 14 days and more than 14 days according to the positive nucleic acid duration. The results revealed that there were significant differences in the vitality value and mental health value of patients aged 46 to 69 in the subgroup where the positive nucleic acid duration longer than 14 days (p= 0.0472; p= 0.0311< 0.05, respectively). Similarly, there are also significant differences in role-emotional value in different genders (p= 0.0316). CONCLUSION: The study described the psychometric properties of COVID-19 patients without comorbidities shortly after discharge. Risk factors for psychometric properties damage included age, male sex, and nucleic acid duration.

Reduced Circulating Levels of miR-433 and miR-133b Are Potential Biomarkers for Parkinson's Disease.

Aberrant expression of microRNA (miRNA) in tissues may lead to altered level in circulation. Considerable evidence has suggested that miRNA deregulation is involved in the pathogenesis of Parkinson's disease (PD). In this study, we screened a set of PD-associated miRNAs and aimed to identify differentially expressed miRNAs in plasma of PD patients and to evaluate their potentiality to serve as PD biomarkers. A total of 95 subjects consisting of 46 sporadic PD cases and 49 controls were recruited. Plasma levels of six miRNAs including miR-433, miR-133b, miR-34b, miR-34c, miR-153, and miR-7 were evaluated using reverse transcribed quantitative PCR, among which we found that miR-34c and miR-7 were below detection limit under our condition. The results showed that levels of circulating miR-433 (P = 0.003) and miR-133b (P = 0.006), but not miR-34b and miR-153, were reduced in PD patients. miR-433 and miR-133b were strongly correlated in both control and PD groups (rs = 0.87 and 0.85, respectively). The correlation between miR-34b and miR-153 expressions was significantly reduced (P < 0.05) in the PD group. Although miR-433 and miR-133b were likely to be functionally complimentary as suggested by Pathway and Gene Ontology analyses, these two miRNAs per se might not be sufficient to predict PD. No correlation was observed between the four miRNAs and age or severity of disease. Collectively, our results demonstrate that circulating miR-433 and miR-133b are significantly altered in PD and may serve as PD biomarkers.

Hyperoside inhibits lipopolysaccharide-induced inflammatory responses in microglial cells via p38 and NFκB pathways.

Hyperoside (quercetin-3-O-ß-d-galactoside) is an active compound isolated from herbs. Neuroinflammation is a key mechanism involved in neurodegenerative disorders including Parkinson's disease. In this study, we aimed to investigate the potentiality of hyperoside in inhibiting microglia-mediated neuroinflammation. BV2 microglial cells were pretreated with hyperoside and stimulated with lipopolysaccharide (LPS). The results showed that hyperoside significantly inhibited LPS-induced production of nitric oxide and pro-inflammatory cytokines including IL-1ß and TNF-α, as well as the expression of inducible nitric oxide synthase. Similar results were observed in primary microglial cells isolated from neonatal mice. Analyses in MAPK and NFκB signaling combined with specific inhibitors suggested that hyperoside attenuated the LPS-induced inflammatory responses via p38 and NFκB pathways. Furthermore, hyperoside suppressed reactive microglia-mediated neurotoxicity as evidenced by conditioned media culture, but had no direct impact on MPP+-induced toxicity in SH-SY5Y neuroblastoma cells. Collectively, our data suggest that hyperoside may serve as a protective agent by alleviating microglia activation in disorders such as Parkinson's disease.

Paramedian Thalamic Ischemic Infarction: A Retrospective Clinical Observation.

BACKGROUND: The study aimed to evaluate the clinical features in patients with bilateral and unilateral paramedian thalamic infarcts. METHODS: Twenty-one patients with paramedian thalamic infarcts were included, and their case records were reviewed. We focused on the patients' neuroimaging and neurological symptoms including the duration of coma, vertical gaze palsy, and memory impairment. The causes of bilateral and unilateral paramedian thalamic infarcts were also investigated. RESULT: Nine patients had bilateral paramedian thalamic infarcts and 12 patients had unilateral lesions. As an initial symptom, coma had occurred in 5 patients with bilateral lesions and 4 patients with unilateral lesions. Bilateral vertical gaze palsy and memory impairment were found in both groups. Most of them recovered well, except 1 patient who died due to bilateral thalamic paramedian infarction. CONCLUSIONS: Our results show that both bilateral and unilateral paramedian thalamic infarcts can cause coma, vertical gaze palsy, and memory impairment. This may promote our understanding of paramedian thalamic infarction.

Effect of Extracellular Vesicles on Neural Functional Recovery and Immunologic Suppression after Rat Cerebral Apoplexy.

BACKGROUND: Previous studies have demonstrated that mesenchymal stem cells (MSCs) can promote the recovery of neural function after cerebral apoplexy by secreting multiple cytokines. In addition, cell factor-derived extracellular vesicles play an important role in recovery of neural function. The aim of this study was to determine the effect of extracellular vesicles on neural functional recovery and brain tissue remodeling after cerebral apoplexy in a rat model. METHODS: The rat models with local ischemic stroke was established and three random groups were created. In groups A and B, human bone marrow-derived MSCs and MSC-derived extracellular vesicles were transplanted into rats. In the control group (group C), only normal saline was injected. Then, we evaluated motor coordination ability, pathologic changes of the brain, immune responses in the central and peripheral nervous systems, regeneration of blood vessels, and nervous tissue in 4 weeks after cerebral apoplexy. RESULTS: Obvious regeneration of blood vessels and nervous tissues were identified in groups A and B. There was no significant difference with respect to coordination between groups A and B, but coordination in groups A and B was significantly better than the control group. Immunohistochemical staining of brain tissue showed that extracellular vesicles exerted no effect on infiltration of immune cells in the central nervous system. Weakened immune suppression was noted 1 week after cerebral apoplexy, which provided a favorable environment for remodeling of brain tissue. CONCLUSION: MSC-derived extracellular vesicles accelerated neural functional recovery after cerebral apoplexy. The weakened immune suppression was beneficial to remodeling of brain tissue.

Src Family Kinases in Brain Edema After Acute Brain Injury.

Brain edema, the first stage of intracranial hypertension, has been associated with poor prognosis and increased mortality after acute brain injury such as ischemic stroke, intracranial hemorrhage (ICH), and traumatic brain injury (TBI). Acute brain injury often initiates release of many molecules, including glutamate, adenosine, thrombin, oxyhemoglobin, cytokines, reactive oxygen species (ROS), damage-associated molecular pattern molecules (DAMPs), and others. Most of these molecules activate Src family kinases (SFKs), a family of proto-oncogenic non-receptor tyrosine kinases, resulting in blood-brain barrier (BBB) disruption and brain edema at the acute stage after brain injury. However, SFKs also contribute to BBB self-repair and brain edema resolution in the chronic stage that follows brain injury. In this review, we summarize possible pathways through which SFKs are implicated in both brain edema formation and its eventual resolution.

CD163/Hemoglobin Oxygenase-1 Pathway Regulates Inflammation in Hematoma Surrounding Tissues after Intracerebral Hemorrhage.

BACKGROUND: The aim of the present study was to investigate changes in the expression of CD163 and hemoglobin oxygenase-1 (HO-1) in brain tissue surrounding hematomas after intracerebral hemorrhage (ICH), and correlations with other factors. MATERIALS AND METHODS: Brain tissues in the close surrounding of ICH hematomas (n = 27, ICH group) were collected at 6 hours or less, 6-24 hours, 24-72 hours, and more than 72 hours after bleeding onset, and more distant tissues (n = 12, control group) were histologically analyzed with hematoxylin and eosin staining and transmission electron microscopy. Interleukin (IL)-1, IL-10, and tumor necrosis factor-alpha, as well as the expression of CD163 and HO-1, were assessed using immunochemistry, Western blotting, and reverse transcription-polymerase chain reaction. Apoptosis rates were determined with terminal deoxynucleotidyl transferase dUTP nick end labeling assays. RESULTS: The expressions of the inflammatory cytokines IL-1 and tumor necrosis factor-alpha were increased at 6-24 hours (P <.05), reached a peak at 24-72 hours (P <.001 and P <.01), at which time histopathological changes became most obvious and apoptosis rates were highest, but diminished for more than 72 hours after ICH onset. The anti-inflammatory cytokine IL-10 peaked at 6-24 hours (P < .01) after ICH onset but dropped in the following periods to lower levels than the control (P <.05). CD163 and HO-1 expressions gradually increased from 6 to 24 hours to peaks at more than 72 hours after ICH onset (P <.001). CONCLUSION: The highest inflammation level in tissues surrounding ICH hematomas occurred 2-3 days after bleeding onset, but was accompanied by an anti-inflammatory factor IL-10 expression enhancement. In the period of more than 72 hours after ICH onset, CD163 and HO-1 expressions reached peaks and inflammatory cytokine expressions dropped.

Aldehyde dehydrogenase 2 genetic variations may increase susceptibility to Parkinson's disease in Han Chinese population.

Genetic variations of ALDH2, encoding aldehyde dehydrogenase-2 which regulates aldehyde oxidation in the brain, have been recently suggested to impact on the association of pesticide exposure with Parkinson's disease (PD). However, the link between ALDH2 polymorphism and PD remains elusive. In the present study, tag-single nucleotide polymorphisms of ALDH2, including rs4767944, rs441, and rs671, were extracted and analyzed in a Chinese cohort consisting of 584 PD patients and 582 controls. Results from genotyping analyses showed that rs4767944 (p = 0.002), but not rs441 and rs671, were associated with PD. The C allele of rs4767944 served a risk factor toward PD. Further analysis presented a significant association between haplotype frequencies and the risk for PD, primarily driven by the preponderance of the C-T-A (p = 0.03) or C-T-G (p = 0.003) haplotype of rs4767944, rs441, and rs671 in PD patients. In conclusion, these novel results suggest an association between PD susceptibility and ALDH2 genetic variations.

Assessing plasma levels of selenium, copper, iron and zinc in patients of Parkinson's disease.

Trace elements have been recognized to play an important role in the development of Parkinson's disease (PD). However, it is difficult to precisely identify the relationship between these elements and the progression of PD because of an insufficient number of patients. In this study, quantifications of selenium (Se), copper (Cu), iron (Fe) and zinc (Zn) by atomic absorption spectrophotometry were performed in plasma from 238 PD patients and 302 controls recruited from eastern China, which is so far the largest cohort of PD patients and controls for measuring plasma levels of these elements. We found that plasma Se and Fe concentrations were significantly increased whereas Cu and Zn concentrations decreased in PD patients as compared with controls. Meanwhile, these four elements displayed differential changes with regard to age. Linear and logistic regression analyses revealed that both Fe and Zn were negatively correlated with age in PD patients. Association analysis suggests that lower plasma Se and Fe levels may reduce the risk for PD, whereas lower plasma Zn is probably a PD risk factor. Finally, a model was generated to predict PD patients based on the plasma concentrations of these four trace elements as well as other features such as sex and age, which achieved an accuracy of 80.97±1.34% using 10-fold cross-validation. In summary, our data provide new insights into the roles of Se, Cu, Fe and Zn in PD progression.

[Clinical and neurophysiological features of 700 patients with diabetic peripheral neuropathy].

OBJECTIVE: To study the clinical and electrophysiological features of diabetic peripheral neuropathy in 700 patients to elucidate the relationships between them and evaluate the value of electromyography in the diagnosis of diabetic peripheral neuropathy. METHODS: Standard sensory and motor nerve conduction studies were performed in the 700 patients, sensory nerve conduction velocity (SCV), amplitude of sensory nerve action potential (SNAP), distal motor latency (DML) and amplitude of compound muscle action potential (CMAP) of median nerve, ulnar nerve, posterior tibial nerve and common peroneal nerve were studied simultaneously. Needle electromyogram (EMG) test was performed in 239 patients. RESULTS: (1) The most common symptoms of peripheral neuropathy were numbness and pain in limbs, while impaired or lost tendon reflexes were the most common abnormal signs in lower limbs. (2) The abnormal rate of nerve conduction studies was 72.4% in the 700 patients. Slow SCV, prolonged DML and decreased amplitude of SNAP and CMAP were detected. (3) More severe abnormal nerve conduction was found in lower limbs than in upper limbs. The abnormal degree was more severe in sensory nerve than in motor nerve and severity was more in amplitude than in conduction velocity (P < 0.05). (4) Abnormal motor and/or sensory nerve conduction was detected in 67.3% of the patients with clinical manifestations of neuropathy and 5.1% patients without signs or symptoms of neuropathy, while motor or sensory nerve conduction was normal in 27.6% patients with manifestations of neuropathy. Needle EMG showed neurogenic lesion in 4.6% of the patients with normal motor and sensory nerve conduction. (5) polyneuropathy is the most common type of diabetic neuropathy and carpal tunnel syndrome the next. CONCLUSIONS: The most common clinical and electrophysiological manifestation of diabetic neuropathy is sensory disturbance, which is more severe in lower limbs. The electrophysiological changes are not always accordant with clinical manifestations. Subclinical diabetic peripheral neuropathy can be detected by electrophysiological tests, which are useful to verify the range and extent of the nerve lesion involved in the early stage of diabetic peripheral neuropathy. Needle EMG is not recommended for screening diabetic neuropathy.