Motor Nerve Conduction Velocity Research Articles

P62/sequestosome-1 as a severity-reflecting plasma biomarker in Charcot–Marie–Tooth disease type 1A

Autophagy is a self-degradation system for recycling to maintain homeostasis. p62/sequestosome-1 (p62) is an autophagy receptor that accumulates in neuroglia in neurodegenerative diseases. The objective of this study was to determine the elevation of plasma p62 protein levels in patients with Charcot–Marie–Tooth disease 1A (CMT1A) for its clinical usefulness to assess disease severity. We collected blood samples from 69 CMT1A patients and 59 healthy controls. Plasma concentrations of p62 were analyzed by ELISA, and we compared them with Charcot-Marie-Tooth neuropathy score version 2 (CMTNSv2). A mouse CMT1A model (C22) was employed to determine the source and mechanism of plasma p62 elevation. Plasma p62 was detected in healthy controls with median value of 1978 pg/ml, and the levels were significantly higher in CMT1A (2465 pg/ml, p < 0.001). The elevated plasma p62 levels were correlated with CMTNSv2 (r = 0.621, p < 0.0001), motor nerve conduction velocity (r = − 0.490, p < 0.0001) and disease duration (r = 0.364, p < 0.01). In C22 model, increased p62 expression was observed not only in pathologic Schwann cells but also in plasma. Our findings indicate that plasma p62 measurement could be a valuable tool for evaluating CMT1A severity and Schwann cell pathology.

Clinical effect of acupuncture combined with medication on diabetic peripheral neuropathy and its influence on serum lipid metabolism

To observe the clinical effect on diabetic peripheral neuropathy (DPN) treated with acupuncture combined with medication and explore its effect mechanism. Sixty-two patients of DPN were randomly divided into a combined therapy group (31 cases) and a medication group (31 cases, 2 cases dropped out); besides, 20 healthy subjects were recruited as a normal group. On the base of routine intervention, in the medication group, thioctic acid capsules were administrated orally, 0.2 g each time, 3 times a day. In the combined therapy group, besides the medication as the medication group, acupuncture was performed on bilateral Quchi (LI 11), Waiguan (TE 5), Hegu (LI 4), Tianshu (ST 25), Zusanli (ST 36), Sanyinjiao (SP 6) and Taichong (LR 3) and the needles were retained for 30 min, acupuncture was delivered once daily, 6 times a week. The duration of treatment was 4 weeks in the two groups. The score of Toronto clinical scoring system (TCSS), the nerve conduction velocity of median nerve (MN) and common peroneal nerve (CPN) were observed before and after treatment in the two intervention groups; and the serum lipid metabolism was detected before and after treatment in the two intervention groups and the normal group. Compared with that before treatment, the scores of TCSS were reduced in the combined therapy group and the medication group (P<0.05) after treatment, and the score decrease in the combined therapy group was larger than that of the medication group (P<0.001). The motor nerve conduction velocity and the sensory nerve conductive velocity of MN and CPN after treatment all increased in the combined therapy group and the medication group compared with those before treatment (P<0.05), and the improvements in the combined therapy group were larger than those of the medication group (P<0.001). Before treatment DPN patients had 365 differential lipid metabolites, including sphingosine (SPH, d18:0), involved in the inositol phosphate metabolism, compared with the subjects of the normal group. There were 103 differential lipid metabolites in the medication group before and after treatment, including lysophosphatidyl ethanolamine (LPE, 18:1/0:0), participated in glycerophospholipid metabolism. In the combined therapy group, before and after treatment, there were 99 differential lipid metabolites, including lysophosphatidylcholine (LPC, 18:0/0:0), participated in the neuroactive ligand-receptor interaction. Acupuncture greatly affected 50 lipid metabolites such as lysophosphatidic acid (LPA, 0:0/22:6), LPA(0:0/18:2) and LPC(O-18:0), which was mainly involved in glycerophospholipid metabolism. Acupuncture combined with medication ameliorates the symptoms and the nerve conduction velocity in DPN patients, which may be related to the regulation of serum lipid metabolism.

Correlation and influencing factors of neurophysiological examinations and serum uric acid in patients with diabetic peripheral neuropathy: an exploratory study

Objective This study aimed to investigate the correlation and influencing factors between neurophysiological examinations, serum uric acid (SUA), and glucose metabolism in patients with Diabetic Peripheral Neuropathy (DPN). Methods A total of 114 patients with DPN who received treatment at the Endocrinology Department of our hospital from January 2022 to December 2023 were included. According to the median blood uric acid level, the patients were divided into high SUA group and low SUA group, and the demographic data, blood glucose indexes and motor nerve electrophysiological examination results of the two groups were compared. Results The level of FPG and HbA1c was higher in the high SUA group. The motor nerve latency of the high SUA group was higher, the motor nerve amplitude and motor nerve conduction velocity of the high SUA group were lower than those of the low SUA group. SUA was positively correlated with motor nerve latency and negatively correlated with motor nerve amplitude and conduction velocity. Conclusion In DPN, high SUA levels are associated with poor glycemic control. With the increase in SUA levels, the motor nerve latency in patients with T2DM is prolonged, and amplitude and conduction velocity decrease, and high SUA is a risk factor and potential predictor of DPN.

Cubital Tunnel Syndrome Due to Intraneural Ganglion Cysts of the Ulnar Nerve With Joint-Cyst Connection at the Elbow

BACKGROUND AND OBJECTIVES: The unifying articular theory suggests that intraneural ganglion cysts in the cubital tunnel arise from the elbow joint and are connected to the ulnar nerve through an articular branch. This study aimed to report our clinical experience with these cysts and our surgical findings and outcomes. METHODS: We retrospectively analyzed 13 patients who underwent surgery for cubital tunnel syndrome caused by an intraneural ganglion cyst of the ulnar nerve. Clinical symptoms, physical examination findings, nerve conduction testing electromyography, plain radiography, and ultrasonography were evaluated before and after surgery. MRI was performed in 2 patients. Cyst decompression, disconnection of the articular branch, and ulnar nerve transposition were performed in all. RESULTS: The mean follow-up was 29 months. After surgery, local elbow pain and Tinel sign disappeared in all patients, and the average Numerical Rating Scale dropped from 3.7 (2-5) to 0 (0-0). Two-point discrimination testing was normal (&lt;5.0 mm) in 12 patients. Wartenberg sign and “claw hand” deformity became negative, and muscle function and motor nerve conduction velocity were improved in 12 patients. The Medical Research Council muscle strength grade was M4 or M5 in the flexor carpi ulnaris, flexor digitorum profundus of the 4th and 5th digits, and first dorsal interosseous muscle in 12 patients. Postoperative spontaneous potentials including fibrillation and sharp waves, and motor unit recruitment in the first dorsal interosseous muscle were obviously improved. A cystic articular branch was confirmed during surgery in all patients. No cyst recurred clinically or on follow-up ultrasonography. CONCLUSION: The unifying articular theory of intraneural ganglion cysts applies to those located in the ulnar nerve at the elbow. Surgical disconnection of the articular nerve branch from the ulnar nerve eliminated the pathway for cyst recurrence and achieved good long-term outcomes.

Electroacupuncture improves peripheral neuropathy by up-regulating Sirt1/PGC-1α/TFAM pathway in type 2 diabetes rats with peripheral neuropathy.

To observe the effect of electroacupuncture (EA) on activation of silent information regulator 1 (Sirt1)/peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α)/mitochondrial transcription factor A (TFAM) pathway in type 2 diabetes (T2DM) rats with peripheral neuropathy (DPN) , so as to explore its possible mechanisms underlying improvement of DPN. Thirty male SD rats were randomly divided into blank control group (n=8) and DPN model group (n=22) which were further divided into model group (n=8) and EA group (n=8) after successful modeling. The model of T2DM was established by high-fat diet and low-dose intraperitoneal injection of streptozocin (35 mg/kg). For rats of the EA group (anesthetized with isoflurane), EA stimulation (2 Hz/15 Hz, 2 mA) was applied to "Tianshu"(ST25) for 20 min, once daily, 6 times a week for 6 weeks. The blood glucose level, body weight, area under curve (AUC) of glucose tolerance test, and hind-paw mechanical pain threshold and thermal pain threshold were observed. The intra-epidermal nerve fiber density (IENFD) of the hind-foot pad was observed by immunofluorescence staining. The motor nerve conduction velocity (MNCV) of the sciatic nerve was measured by using electrophysiological method. H.E. staining was used to observe the histopathological changes of the sciatic nerve after modeling. Transmission electron microscopy (TEM) was used to observe the ultrastructural changes of the sciatic nerve. The protein expressions of energy-related Sirt1, PGC-1α and TFAM in the sciatic nerve was detected by Western blot. Compared with the blank control group, the model group had a higher blood glucose contents and AUC (P<0.001), a slower MNCV (P<0.01), and a decrease in the body weight and in the mechanical and thermal pain thresholds (P<0.001) and IENFD (P<0.001), and in the expression levels of Sirt1, PGC-1α and TFAM (P<0.05, P<0.01). In contrast to the model group, the EA group had a decrease in the blood glucose contents and AUC (P<0.05, P<0.01), and an increase in mechanical and thermal pain thresholds, MNCV, IENFD, and expression levels of Sirt1, PGC-1α and TFAM proteins (P<0.01, P<0.05). In addition, results of histopathological and ultrastructural changes of the sciatic nerve showed more fragmented and disordered distribution of axons on the transverse section, and extensive separation of myelin and axons, uneven myelin thickness, axonal degeneration and irregular shape in the model group, whereas in the EA group, the axons on the transverse section were relatively more dense and more complete, the myelin sheath of the sciatic nerve was relatively uniform, and the axonal shape was relatively regular with relatively milder lesions. EA up-regulates the expressions of Sirt1, PGC-1α, TFAM in T2DM rats with DPN, which may be associated with its functions in improving and repairing the injured peripheral nerves in rats with DPN.

Assessing Nerve Conduction Velocity as a Diagnostic and Prognostic Indicator in Leprosy Patients: A Cross-Sectional Study.

Introduction Hansen's disease is a condition in which patients develop peripheral neuropathy. In 1873, G. H. A. Hansen discovered Mycobacterium leprae, the causative agent of leprosy, a chronic infectious disease. These bacteria influence the peripheral nerves, which is likely to cause neuropathy. Sensory nerve conduction studies were performedin leprosy patients on the upper limb nerves of 30 patients in the rural area of the Wardha district in the Indian population. Methods In this study, we recruited 30 leprosy patients fromthe Department of Dermatology and A.V.B.R. Hospital, Sawangi Wardha. The patient's nerve conduction velocity (NCV) tests were carried out in the Department of Physiology at J. N. Medical College, Wardha. NCVs were obtained during these three years, beginning in 2009, while performing sensory nerve conduction velocity (SNCV) and motor nerve conduction velocity (MNCV). The latency, amplitude, and NCV parameters were recorded, and the data collection period ended in 2011. In this study, we measured both MNCVand SNCV. Results In our study, impairment of conductional velocity was observed. In leprosy patients, the MNCV values of latency, amplitude, and conductional velocity were 6.61, 3.89, and 46.92 m/s, respectively, whereas the SNCV values were 3.005, 25.17, and 38 m/s, respectively. Based on the results, it appears that the maximal sensory nerve involvement was recorded at 38 m/s conductional velocity.In NCVs, increased latency and decreased conductional velocity were found across the study. Conclusion It was concluded that nerve conduction studies are one of the non-invasive techniques for early diagnosis and management of leprosy. This study should be repeated with a larger sample size and should be multicentric.

Effect of flipped venous catheter combined with spinal cord electrical stimulation on functional recovery in patients with sciatic nerve injury.

This study aimed to explore the effect of flipped venous catheters combined with spinal cord electrical stimulation on functional recovery in patients with sciatic nerve injury. 160 patients with hip dislocation and sciatic nerve injury were divided into conventional release and flipped catheter + electrical stimulation groups according to the treatment methods (n=80). Motor nerve conduction velocity (MCV) and lower limb motor function were compared. Serum neurotrophic factors brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were compared. The frequency of complications and quality of life were also compared. The MCV levels of the common peroneal nerve and tibial nerve in the flipped catheter + electrical stimulation group were greater than the conventional lysis group (p<0.05). After treatment, the lower extremity motor score (LMEs) in the flipped catheter + electrical stimulation group was greater than the conventional lysis group (p<0.05). The serum levels of BDNF and NGF in the flip catheter + electrical stimulation group were higher than the conventional lysis group (p<0.05). The complication rate in the flipped catheter + electrical stimulation group was lower than in the conventional release group (6.25% vs. 16.25%, p<0.05). The quality-of-life score in the flip catheter + electrical stimulation group was greater than the conventional lysis group (p<0.05). The flipped venous catheter combined with spinal cord electrical stimulation can improve nerve conduction velocity, lower limb motor function, serum BDNF and NGF levels, reduce complications, and help improve the quality of life of sufferers with sciatic nerve injury. Chictr.org.cn ID: ChiCTR2400080984.

Lack of effect from genetic deletion of Hdac6 in a humanized mouse model of CMT2D.

Inhibition of HDAC6 has been proposed as a broadly applicable therapeutic strategy for Charcot-Marie-Tooth disease (CMT). Inhibition of HDAC6 increases the acetylation of proteins important in axonal trafficking, such as α-tubulin and Miro, and has been shown to be efficacious in several preclinical studies using mouse models of CMT. Here, we sought to expand on previous preclinical studies by testing the effect of genetic deletion of Hdac6 on mice carrying a humanized knockin allele of Gars1, a model of CMT-type 2D. Gars1ΔETAQ mice were bred to an Hdac6 knockout strain, and the resulting offspring were evaluated for clinically relevant outcomes. The genetic deletion of Hdac6 increased α-tubulin acetylation in the sciatic nerves of both wild-type and Gars1ΔETAQ mice. However, when tested at 5 weeks of age, the Gars1ΔETAQ mice lacking Hdac6 showed no changes in body weight, muscle atrophy, grip strength or endurance, sciatic motor nerve conduction velocity, compound muscle action potential amplitude, or peripheral nerve histopathology compared to Gars1ΔETAQ mice with intact Hdac6. Our results differ from those of two previous studies that demonstrated the benefit of the HDAC6 inhibitor tubastatin A in mouse models of CMT2D. While we cannot fully explain the different outcomes, our results offer a counterexample to the benefit of inhibiting HDAC6 in CMT2D, suggesting additional research is necessary.

SORD-deficient rats develop a motor-predominant peripheral neuropathy unveiling novel pathophysiological insights.

Biallelic SORD mutations cause one of the most frequent forms of recessive hereditary neuropathy, estimated to affect approximately 10,000 patients in North America and Europe alone. Pathogenic SORD loss-of-function changes in the encoded enzyme sorbitol dehydrogenase result in abnormally high sorbitol levels in cells and serum. How sorbitol accumulation leads to peripheral neuropathy remains to be elucidated. A reproducible animal model for SORD neuropathy is essential to illuminate the pathogenesis of SORD deficiency and for preclinical studies of potential therapies. Therefore, we have generated a Sord knockout (KO), Sord-/-, Sprague Dawley rat, to model the human disease and to investigate the pathophysiology underlying SORD deficiency. We have characterized the phenotype in these rats with a battery of behavioral tests as well as biochemical, physiological, and comprehensive histological examinations. Sord-/- rats had remarkably increased levels of sorbitol in serum, cerebrospinal fluid (CSF), and peripheral nerve. Moreover, serum from Sord-/- rats contained significantly increased levels of neurofilament light chain, NfL, an established biomarker for axonal degeneration. Motor performance significantly declined in Sord-/- animals starting at ∼7 months of age. Gait analysis evaluated with video motion tracking confirmed abnormal gait patterns in the hindlimbs. Motor nerve conduction velocities of the tibial nerves were slowed. Light and electron microscopy of the peripheral nervous system revealed degenerating myelinated axons, de- and remyelinated axons, and a likely pathognomonic finding - enlarged "ballooned" myelin sheaths. These findings mainly affected myelinated motor axons; myelinated sensory axons were largely spared. In summary, Sord-/- rats develop a motor-predominant neuropathy that closely resembles the human phenotype. Our studies revealed novel significant aspects of SORD deficiency, and this model will lead to an improved understanding of the pathophysiology and the therapeutic options for SORD neuropathy.

Exercise May Increase Oxidative Stress in the Sciatic Nerve in Streptozotocin-Induced Diabetic Rats.

Background and Objectives: Diabetic peripheral neuropathy (DPN) affects approximately half of patients with diabetes mellitus (DM), contributing to falls and fractures. Oxidative stress, which is linked to DM-induced hyperglycemia, has been implicated in the onset of DPN. Although exercise is recommended for patients with DM, its effect on DPN remains unclear. Therefore, this study aimed to investigate the effect of exercise on DPN and the mechanisms involved. Material and Methods: Thirty male Wistar rats were divided into control, streptozotocin (STZ)-induced diabetic (DM), and STZ-induced diabetic/exercise (DM + Ex) groups. Diabetes was induced using STZ injection. Rats in the DM + Ex groups underwent six weeks of treadmill exercise. Sciatic nerve parameters, which included motor nerve conduction velocity (MNCV), antioxidant enzymes (catalase, glutathione peroxidase [GPx], and superoxide dismutase [SOD]), oxidative stress markers (malondialdehyde [MDA] and 4-hydroxy-2-nonenal [4HNE]), and neurotrophic factors (brain-derived neurotrophic factor [BDNF] and nerve growth factor [NGF]), were examined. Results: Exercise alleviated DM-induced decreases in MNCV in rats. Although exercise did not significantly affect antioxidant enzyme activity, 4HNE levels increased significantly, indicating increased oxidative stress. Additionally, exercise did not significantly affect DM-induced increases in NGF and BDNF levels in rats. Conclusions: Exercise may prevent DPN in rats with DM, possibly through nonantioxidant mechanisms.

Pathologic classification of a late-onset peripheral neuropathy in a spontaneous Labrador retriever dog model.

Late-onset peripheral neuropathy (LPN) is a heritable canine neuropathy commonly found in Labrador retrievers and is characterized by laryngeal paralysis and pelvic limb paresis. Our objective was to establish canine LPN as a model for human hereditary peripheral neuropathy by classifying it as either an axonopathy or myelinopathy and evaluating length-dependent degeneration. We conducted a motor nerve conduction study of the sciatic and ulnar nerves, electromyography (EMG) of appendicular and epaxial musculature, and histologic analysis of sciatic and recurrent laryngeal nerves in LPN-affected and control dogs. LPN-affected dogs exhibited significant decreases in compound muscle action potential (CMAP) amplitude, CMAP area, and pelvic limb latencies. However, no differences were found in motor nerve conduction velocity, residual latencies, or CMAP duration. Distal limb musculature showed greater EMG changes in LPN-affected dogs. Histologically, LPN-affected dogs exhibited a reduction in the number of large-diameter axons, especially in distal nerve regions. In conclusion, LPN in Labrador retrievers is a common, spontaneous, length-dependent peripheral axonopathy that is a novel animal model of age-related peripheral neuropathy that could be used for fundamental research and clinical trials.

Surgical Decision Making for Mild-to-Moderate Cubital Tunnel Syndrome

PurposeThe management of ulnar (UN) neuropathy remains unclear as there are neither consensus guidelines nor compelling data available to inform optimal treatment. Identifying patients in the mild to moderate group that would benefit most from surgery is challenging as their symptoms can be subtle and less debilitating. This study investigated predictors of surgical intervention among patients presenting with McGowan mild and moderate cubital tunnel syndrome (CuTS). MethodsThis is an institutional review board–approved study. Patients evaluated from March 2016 to July 2022 were included if they were diagnosed with McGowan mild or moderate CuTS and underwent concurrent electrodiagnostic and ultrasound (US) evaluations. Patient demographics, symptom presentation, clinical and diagnostic test findings were analyzed. Variables were analyzed using Student’s t-test, Mann-Whitney U-Test or Pearson’s χ2 test. Multivariable logistic regression was used to assess the association of covariates and surgery. Results73 patients and 103 elbows were identified. The mean age and BMI were 51 and 26 respectively. Most patients were male, right-hand dominant, and unilaterally symptomatic in the dominant hand. Twenty-six elbows were surgically treated. Bivariable analyses by surgical treatment showed that patients who underwent surgery more often had positive electrodiagnostic findings including motor nerve conduction velocity (CVm) <50m/s and a >10m/s CVm difference across the forearm compared to elbow.Fifty-nine cases were categorized as electrodiagnostically normal. Of the electrodiagnostically normal cases 29 had positive findings of CuTS on US. Logistic regression model showed that electrodiagnostically severe cases had 3.7 times higher odds of being surgically treated than normal counterparts (OR: 3.7, 95%CI: 1.11-12.6; p=0.03). ConclusionNot many differences in objective findings identify patients who should receive operative treatment. In addition to test results, more subjective findings from the patient such as patient-reported level of impairment may be able to bridge this gap in surgical decision making. Clinical RelevanceThis study contributes to treatment decision-making for mild and moderate cubital tunnel syndrome.

The Relationship Between Smartphone Usage Duration with Hand Grip, Pinch Grip Strength and It’s Impact on NCS Motor Parameters of Median Nerve in Young Population – An Observational Study

Background: There seems to be a lack of literature regarding the association between handgrip strength and nerve conduction parameters of the median nerve among smartphone users in the young population. There is a need to investigate the inter-relation of grip strength with smartphone usage and motor parameters of the median nerve by carrying out a nerve conduction study. Aims: The study aims to find out the correlation between hand-grip and pinch-grip strength on nerve conduction study motor parameters among smartphone users. Methods and Material: 112 young adult participants were included. Hang grip strength and pinch grip strength were assessed for both hands and after three trials, the average was calculated. The average screen time of their smartphones over the past week was noted, and simultaneously, the motor nerve conduction study parameter of the median nerve was performed. Statistical analysis: Pearson’s correlation was applied to find out the correlation between the component of the handgrip, pinch grip, and motor nerve conduction velocity of the median nerve. The p-value of &lt; 0.001 was considered statistically significant. Results: The study obtained a significant negative correlation between smartphone usage with amplitude and nerve conduction velocity and a significant positive correlation with the latency of the median nerve. Conclusions: The study concluded that smartphone usage reduces the hand grip and pinch grip strength and significantly affects the motor parameters of the median nerve. KEYWORDS: Smartphone screen time, hand grip strength, pinch grip strength, median nerve.

Mitofusin 2 Variant Presenting With a Phenotype of Multiple System Atrophy of Cerebellar Subtype.

To investigate the etiology of cerebellar ataxia in an adult male patient. We performed standard neurologic assessment and genome sequencing of a 62-year-old man with rapidly progressive balance and gait abnormalities. The propositus exhibited cognitive dysfunction, mild appendicular bradykinesia, prominent appendicular ataxia, dysarthria, and hypomimia with minimal dysautonomic symptoms. Nerve conduction studies showed mild peripheral sensory neuropathy and normal motor nerve conduction velocities. Brain imaging showed progressive cerebellar atrophy and gliosis of the olivopontocerebellar fibers, characterized by T2 hyperintensity within the pons. Genetic testing revealed a likely pathogenic germline variant in MFN2 (NM_014874: c.[838C>T];[=], p.(R280C)) in the GTPase domain (G) interface; pathogenic variants of MFN2 typically cause hereditary sensory and motor neuropathy VI or Charcot-Marie-Tooth disease 2A. The presence of progressive ataxia, "hot cross bun" sign, and dysautonomia has been associated with multiple system atrophy, cerebellar type (MSA-C). We describe progressive cerebellar ataxia in an individual with a deleterious variant in MFN2. Our findings suggest that pathogenic variants in MFN2 can result in a spectrum of phenotypes including cerebellar ataxia with cerebellar-pontine atrophy in the absence of significant neuropathy and in a manner closely resembling MSA-C.

Electrophysiological Evaluation of Common Peroneal Nerve in Chronic Cigarette Smokers.

Background: Researchers have identified multiple negative health effects of smoking on the respiratory and cardiovascular systems. It was recently reported that substances in cigarette smoke also have pathological effects on peripheral nerves, which causes neuronal impairment. The common peroneal nerve conduction study is an essential electrodiagnostic test of the lower limb for the detection of peripheral motor nerve dysfunction.Objectives: To assess the potential influence of smoking on the electrophysiological status of common peroneal nerve in young male chronic cigarette smokers.Materials and Methods: This case-control study was conducted in the Department of Physiology, Sir Salimullah Medical College, Dhaka, from July 2017 to June 2018, including thirty male cigarette smokers aged 25 to 40 years. For comparison, another thirty age and BMI-matched healthy male non-smoker subjects were selected in the control group. The electrophysiological parameters (distal latency, amplitude, and motor nerve conduction velocity) of the left common peroneal nerve were evaluated by standard methods in the Department of Neurology, Dhaka Medical College Hospital. For the statistical analysis, an independent t-test was performed.Result: In this study, the mean distal latency of the common peroneal nerve was slightly prolonged, while the mean amplitude was slightly reduced in smokers. However, these changes were not statistically significant. However, the motor nerve conduction velocity was significantly (p ˂ 0.05) slower in cigarette smokers compared to non-smokers.Conclusion: Chronic cigarette smoking causes significant impairment of common peroneal motor nerve conduction, while it does not affect the amplitude in young individuals. KYAMC Journal Volume: 14, No: 03, October 2023: 111-115.

Dental Stem Cell-Based Therapy for Glycemic Control and the Scope of Clinical Translation: A Systematic Review and Meta-Analysis

Background: The tooth is a repository of stem cells, garnering interest in recent years for its therapeutic potential. The aim of this systematic review and meta-analysis was to test the hypothesis that dental stem cell administration can reduce blood glucose and ameliorate polyneuropathy in diabetes mellitus. The scope of clinical translation was also assessed. Methods: PubMed, Cochrane, Ovid, Web of Science, and Scopus databases were searched for animal studies that were published in or before July 2023. A search was conducted in OpenGrey for unpublished manuscripts. Subgroup analyses were performed to identify potential sources of heterogeneity among studies. The risk for publication bias was assessed by funnel plot, regression, and rank correlation tests. Internal validity, external validity, and translation potential were determined using the SYRCLE (Systematic Review Center for Laboratory Animal Experimentation) risk of bias tool and comparative analysis. Results: Out of 5031 initial records identified, 17 animal studies were included in the review. There was a significant decrease in blood glucose in diabetes-induced animals following DSC administration compared to that observed with saline or vehicle (SMD: −3.905; 95% CI: −5.633 to −2.177; p = 0.0004). The improvement in sensory nerve conduction velocity (SMD: 4.4952; 95% CI: 0.5959 to 8.3945; p = 0.035) and capillary-muscle ratio (SMD: 2.4027; 95% CI: 0.8923 to 3.9132; p = 0.0095) was significant. However, motor nerve conduction velocity (SMD: 3.1001; 95% CI: −1.4558 to 7.6559; p = 0.119) and intra-epidermal nerve fiber ratio (SMD: 1.8802; 95% CI: −0.4809 to 4.2413; p = 0.0915) did not increase significantly. Regression (p &lt; 0.0001) and rank correlation (p = 0.0018) tests indicated the presence of funnel plot asymmetry. Due to disparate number of studies in subgroups, the analyses could not reliably explain the sources of heterogeneity. Interpretation: The direction of the data indicates that DSCs can provide good glycemic control in diabetic animals. However, methodological and reporting quality of preclinical studies, heterogeneity, risk of publication bias, and species differences may hamper translation to humans. Appropriate dose, mode of administration, and preparation must be ascertained for safe and effective use in humans. Longer-duration studies that reflect disease complexity and help predict treatment outcomes in clinical settings are warranted. This review is registered in PROSPERO (number CRD42023423423).

Co-treatment of Astragaloside IV with Vitamin D in Diabetic Peripheral Neuropathic Rats: Protective Effects and Potential Mechanisms.

The potential mechanism underlying the protective effect of Astragaloside IV (AS-IV) co-treatment with 1, 25-dihydroxy-vitamin D (Vit-D) on neuropathy in diabetic high-fat rats was investigated. The rat diabetic hyperlipidemia (DH) model was established via streptozotocin and a high-fat diet (HFD). After co-treatment (of AS-IV and Vit-D at respective doses of 50 mg/kg via oral gavage and 30000 IU/kg via intramuscular injection), blood glucose levels, markers of inflammation and oxidative stress, as well as apoptosis and histopathology were evaluated with appropriate techniques. Co-treatment could effectively reduce blood glucose levels substantially (p< 0.01), improve weight loss, and decrease oral glucose tolerance. Reduced respective sensory and motor nerve conduction velocities in rats were substantially improved (p<0.01) after co-treatment. Also, we observed obvious improvement in DH-induced injured nerve fiber myelin structure and other organ pathologies in co-treated rats. Besides, we observed up-regulated expressions of peroxisomal-proliferator activated receptor-alpha (PPAR-α) and Vit-D receptors (VDR) (p< 0.01) through the western blotting technique. Using the same technique, we also discovered reduced levels of interleukin (IL)1 beta, IL-6, and tumor necrosis factor-alpha, coupled with increased IL-10 and superoxide dismutase levels (p< 0.01). Importantly, co-treatment could effectively exert antioxidative and anti-inflammatory effects. Also, co-treatment resulted in the up-regulation of PPAR-α and VDR expressions, inhibition of the renin-angiotensin-aldosterone system, and promotion of β-cell sensitivity to insulin. The combined application of AS-IV and Vit-D exhibited health effects such as anti-oxidation, regulation of inflammatory factors, and promotion of cell repair, which may be considered as the mechanisms underlying treatment of diabetic peripheral neuropathy and improvement in biochemical indicators.

Gene Distribution in Pediatric-Onset Inherited Peripheral Neuropathy: A Single Tertiary Center in Thailand.

Inherited peripheral neuropathy presents a diagnostic and therapeutic challenge due to its association with mutations in over 100 genes. This condition leads to long-term disability and poses a substantial healthcare burden on society. This study aimed to investigate the distribution of genes and establish the genotype-phenotype correlations, focusing on pediatric-onset cases. Exome sequencing and other analytical techniques were employed to identify pathogenic variants, including duplication analysis of the PMP22 gene. Each patient underwent physical examination and electrophysiological studies. Genotypes were correlated with phenotypic features, such as age at disease onset and ulnar motor nerve conduction velocity. We identified 35 patients with pediatric-onset inherited peripheral neuropathy. Pathogenic or likely pathogenic variants were confirmed in 24 out of 35 (68.6%) patients, with 4 of these variants being novel. A confirmed molecular diagnosis was achieved in 90.9% (10/11) of patients with demyelinating Charcot-Marie-Tooth disease (CMT) and 56.3% (9/16) of patients with axonal CMT. Among patients with infantile-onset CMT (≤2 years), the most common causative genes were MFN2 and NEFL, while GDAP1 and MFN2 were frequent causes among patients with childhood- or adolescent-onset CMT (3-9 years). The MFN2 gene was the most commonly implicated gene, and the axonal type was predominant in this cohort of Thai patients with pediatric-onset inherited peripheral neuropathy.

Proximal and Distal Nerve Conduction Studies in Carpal Tunnel Syndrome

Introduction/Aims: The exact reason for the decrease in median nerve motor conduction velocity (MMCV) in the forearm in carpal tunnel syndrome (CTS) is debatable. However, some studies support the hypothesis of blockage of large, myelinated fibers in the carpal tunnel, and/or retrograde axonal degeneration. We aimed to determine the decrease in the MMCV of the second lumbrical (FMMCVL) and abductor pollicis brevis (APB) muscles recorded in the forearm (FMMCVAPB) in patients with CTS compared with a control group and also to compare the MMCV among CTS subgroups with different severity. Methods: The study included data on the hands of 51 patients and 20 volunteer controls. Patients were divided into four groups according to the severity of the involvement, minimal, mild, moderate, and severe. Routine median, ulnar, and comparative conduction studies were performed. By stimulating the median nerve at the palm, wrist, and elbow, responses were recorded over the APB and second lumbrical muscles. MMCV was assessed in the transcarpal segment (TCMMCV) and forearm. Results: The mean FMMCVAPB and FMMCVL in patients were 53.8 ± 4.2 m/s and 54.3 ± 5.6 m/s, respectively, and were significantly slower than in the controls (P &lt; 0.001 and P = 0.012, respectively). The FMMCVL was significantly decreased in the severe group compared with the other three groups (P &lt; 0.001). FMMCVL and FMMCVAPB relatively decreased as CTS severity increased. Conclusion: In this study, FMMCVAPB and FMMCVL were found significantly slower. Slowing of FMMCVL in the forearm is related to the severity of CTS. The decrease in MMCV in the forearm did not parallel the decrease in TCMMCV. This suggests that retrograde axonal degeneration may be the contributing factor to forearm slowing. There is also an association between axonal degeneration and disease severity.

Normative parameters of motor nerve conduction studies in infants

Introduction. Electromyography (EMG) is a modern method of instrumental neurophysiological diagnostics, which includes two main techniques as nerve conduction studies and needle EMG. Parameters of motor nerve conduction studies have been used in a number of clinical studies to evaluate the effectiveness of treatment in children with spinal muscular atrophy (SMA) during the use of pathogenetic therapy (nusinersen). Now, in our country there are no verified normative parameters of motor nerve conduction studies in infants. It is also worth saying that neonatal screening for identifying SMA patients started in 2023 in our country, and currently gene therapy for this disease is increasingly used, so improving methods for instrumental assessment of the dynamics of the condition during treatment, including using EMG, is relevant. &#x0D; Objective: to determine the normative parameters of motor nerve conduction studies in 1–6 months, 7–12 months, and 13–24 months infants without neurological pathology.&#x0D; Materials and methods: The motor nerve conduction studies were carried out using a 2-channel electromyograph Neuro-MVP-Micro (Russia) with electrical stimulation of the ulnar nerve and registration of the compound muscle action potential (CMAP) from the abductor digiti minimi muscle. This made it possible to determine the main parameters of the negative peak of the CMAP — distal latency, amplitude and area, and calculate the motor nerve conduction velocity (MNCV) along the distal part of the ulnar nerve. The obtained data for each parameter were subject to normal distribution and presented in the form of mean and standard deviation (M±SD), minimum and maximum values (min – max).&#x0D; Results: In the age range of 1–6 months, the amplitude of the CMAP (mV) was 5.0±1.0 (3.0–8.0); CMAP area (ms∙mV) — 9.1 ± 2.1 (5.5–12.9); distal latency (ms) — 2.2 ± 0.2 (1.6–2.5), MNCV (m/s) — 37.5 ± 5.4 (27.5–48.9).&#x0D; In the age range of 7–12 months, the amplitude of the CMAP (mV) was 6.2 ± 1.3 (3.8-9.3); CMAP area (ms∙mV) — 11.7 ± 3.0 (6.5–18.6); distal latency (ms) — 2.0 ± 0.2 (1.4–2.4), MNCV (m/s) – 48.4 ± 4.1 (42.1–55.2).&#x0D; In the age range of 13-24 months, the amplitude of the CMAP (mV) was 6.4 ± 0.6 (5.0-7.3); CMAP area (ms∙mV) — 13.3 ± 2.8 (9.8–18.2); distal latency (ms) — 2.2 ± 0.2 (1.8–2.5), MNCV (m/s) – 52.6 ± 3.8 (41.8–57.3).&#x0D; Conclusion. For the first time, normative parameters of motor nerve conduction studies were obtained in 1–6, 7–12, and 13–24 months infants without neurological pathology. This will make it possible to objectify neurophysiological parameters in neuromuscular diseases in infants.