Decreased nerve conduction velocity may be a predictor of fingertip dexterity and subjective complaints.

We examined the causes of decreased fingertip dexterity in elderly individuals with an aim to improve their quality of life by improving their activities of daily living. We calculated nerve conduction velocity, absolute error during force adjustment tasks, and fingertip dexterity test scores for 30 young (21-34 years old) and 30 elderly (60-74 years old) participants to identify age-related changes. We also assessed subjective complaints of pain, motor function, and numbness. Motor nerve (young: 55.8 ± 3.7 m/s; elderly: 52.2 ± 5.0 m/s) and sensory nerve (young: 59.4 ± 3.4 m/s; elderly: 55.5 ± 5.3 m/s) conduction velocities decreased in an age-dependent manner. Moreover, the decrease of motor nerve conduction velocity was associated with decreased fingertip dexterity (objective index), while the decrease of sensory nerve conduction velocity was associated with subjective complaints of pain and motor function (subjective index).

Regulation of sensory nerve conduction velocity of human bodies responding to annual temperature variations in natural environments.

The extensive research interests in environmental temperature can be linked to human productivity/performance as well as comfort and health; while the mechanisms of physiological indices responding to temperature variations remain incompletely understood. This study adopted a physiological sensory nerve conduction velocity (SCV) as a temperature-sensitive biomarker to explore the thermoregulatory mechanisms of human responding to annual temperatures. The measurements of subjects' SCV (over 600 samples) were conducted in a naturally ventilated environment over all four seasons. The results showed a positive correlation between SCV and annual temperatures and a Boltzmann model was adopted to depict the S-shaped trend of SCV with operative temperatures from 5°C to 40°C. The SCV increased linearly with operative temperatures from 14.28°C to 20.5°C and responded sensitively for 10.19°C-24.59°C, while tended to be stable beyond that. The subjects' thermal sensations were linearly related to SCV, elaborating the relation between human physiological regulations and subjective thermal perception variations. The findings reveal the body SCV regulatory characteristics in different operative temperature intervals, thereby giving a deeper insight into human autonomic thermoregulation and benefiting for built environment designs, meantime minimizing the temperature-invoked risks to human health and well-being.

Prevalence of carpal tunnel syndrome in patients with long-term type 2 diabetes mellitus.

Generally, Carpal tunnel syndrome (CTS) is more common in diabetes mellitus (DM), especially in subjects with coexisting diabetic polyneuropathy (DPN) and/or long-term DM. Based on the analysis of nerve conduction velocity (NCV), the prevalence of CTS and the features of nerve injury were retrospectively explored in type 2 diabetes mellitus (T2DM) patients. In this cohort, there were 353 T2DM patients who were hospitalized in Taiyuan Central Hospitalbetween January 2018 and January 2019. The pathological rates of NCVs between the left and right median nerves were compared, including the gender effect. The examinations were mainly directed to analyze the median nerve injury features. Among 353 patients, 139 patients (39.3%) presented with CTS. These 139 T2DM patients with CTS were then divided into groups based on the nerve injury location and injured nerve type. The prevalence of sensory nerve injury (SNI) was higher than that of motor nerve injury (MNI). The CTS patients had a significantly higher occurrence rate of SNI than MNI (P < 0.05). The abnormal rate of sensory nerve conduction velocity (SCV, P = 0.01) and motor nerve conduction velocity (MCV, P < 0.05) were higher in the right median nerve. No significant differences were detected for other nerves on either side. Significant differences in abnormal rates of SCV of the left (P = 0.04) and the right (P = 0.03) median nerves between the two genders were found. There were no significant abnormalities for other nerves on either side and either gender. Early screening of NCV is needed for T2DM patients to detect CTS with a high prevalence rate. This study suggests that early detection of NCV can identify CTS in the absence of clinical conditions and SNI may occur earlier in long-term T2DM patients with CTS.

Sensory Nerve Conduction Velocity Predicts Improvement of Hand Function with Nerve Gliding Exercise Following Carpal Tunnel Release Surgery.

This study aims to investigate the effects of nerve gliding exercise following carpal tunnel release surgery (NGE-CTRS) and the probing factors affecting the effect of NGE-CTRS on hand function. A total of 86 patients after CTRS participated. Grip strength (grip-s), pinch strength (pinch-s), Semmes-Weinstein monofilament test (SWMT), two-point discrimination (2PD), numbness, pain, and Phalen test (Phalen) were measured and compared between pre- and post-NGE-CTRS. The results showed that the combination of surgery and NGE significantly improved the postoperative grip-s, pinch-s, SWMT, 2PD, numbness, and Phalen; however, no improvement was observed in pain. Background factors that influenced the improved grip-s and pinch-s included gender and preoperative sensory nerve conduction velocity (SCV). Additionally, numbness and Phalen were not affected by age, gender, fault side, bilateral, trigger finger, dialysis, thenar eminence atrophy, motor nerve conduction velocity, SCV, the start of treatment, and occupational therapy intervention. In conclusion, the combination of surgical procedures and NGE showed a high improvement. SCV and time-to-start treatment of intervention for carpal tunnel syndrome may be useful in predicting the function after the intervention.

Electrophysiological and Clinical Improvement in Non-Invasive Treatment of Carpal Tunnel Syndrome.

BACKGROUND AND OBJECTIVE: Carpal tunnel syndrome (CTS) is the most common form of nerve entrapment. Clinically, various signs and symptoms compare due to overexposure to mechanical vibrations transmitted to the wrist bones and cartilage, resulting in compression of the sensory and motor nerve fibers of the median nerve. Early symptoms include nocturnal paresthesia and electromyography reveals reduced sensory nerve conduction velocity. Aim of this study was to evaluate the efficacy of a dietary integrator composed of acetyl-L-carnitine, α-lipoic acid, quercetin, bromelain, pantothenic acid, C and B1 and B2 and B6 and B12 vitamins in patients with early (minimal) carpal tunnel syndrome. METHODS: 36 patients (28 female and 8 male) with early CTS characterized by sensory nerve demyelination and inflammation of the transverse carpal ligament. Patients were divided into two groups, group A (18 patients received physical therapy) and group B (18 patients received physical therapy and an oral integrator). Clinical (sleep quality questionnaire to measure severity of paresthesia) and neurophysiological assessment (Sensory Nerve Conduction Velocity) performed at baseline, and then at 30 and 60 days after treatment. RESULTS: Sleep quality and Sensory Nerve Conduction Velocity data analysis show improvement in both groups at 30 and 60 days, with statistical difference between them in both time of analysis. CONCLUSION: In the early CTS, with sensory fibers damage, use of dietary integrator, such as Micronil Dol®, composed of acetyl-L-carnitine, α-lipoic acid, quercetin, bromelain, pantothenic acid, C and B1 and B2 and B6 and B12 vitamins can be effective in quick recovery of median nerve sensory.

Relationship between the Diabetic Polyneuropathy Index and the Neurological Findings of Diabetic Polyneuropathy.

Objective To achieve an accurate quantification in diabetic polyneuropathy (DPN), we developed a new electrophysiological index that we called the DPN index. The relationship between the DPN index and the neurological findings in diabetic patients was assessed. Methods The DPN index was calculated by the mean value of percentages of four parameters (tibial compound muscle action potential amplitude / F wave minimum latency, sural sensory nerve action potential amplitude / sensory nerve conduction velocity) against the mean normal values. Twenty healthy subjects were recruited as a control group. Patients A total of 348 diabetic patients who were hospitalized in our hospital during the period from December 2016 to August 2019 were retrospectively studied. The correlations between the DPN index and five neurological findings (subjective sensory symptoms, diminished or absent Achilles tendon reflex, impaired tactile and vibration sense, low coefficient of variation of R-R interval) were evaluated. Results The DPN index in healthy subjects was 129.3±32.7%. The DPN index in diabetic patients with one or more neurological findings was significantly lower than that in diabetic patients without any neurological findings (p<0.01: 89.3±27.8% vs. 118.4±21.2%). For each of the five neurological findings, the DPN index in the group with an abnormality was significantly lower than that in the group without any abnormality (each p<0.01). Spearman's correlation coefficients indicated that a greater number of neurological findings resulted in a lower DPN index (r=-0.711, p<0.01). Conclusion Our study suggested that the DPN index is useful for evaluating the severity of DPN.

Study of Electrophysiological Changes in Sensory Nerves Among Diabetic Smokers.

INTRODUCTION: Neuropathy is one of the most troublesome complication affecting individuals with diabetes. The resultant loss of function in peripheral nerves causes loss of protective sensations and impairs patient's ability to perceive incipient or even apparent ulcerations in the feet. AIM: This study was undertaken to test the hypothesis of alteration in electrophysiological parameters of nerve before actual manifestations of neuropathy in type 2 diabetic patients and to analyse the effect of smoking on Sensory Nerve Conduction Velocity (SNCV) of diabetic subjects. MATERIALS AND METHODS: One hundred and twenty diagnosed diabetics were taken as cases while 30 healthy non diabetics were taken as control. Case group was divided into diabetic non-smoker and diabetic smoker. Diabetic smoker were further subdivided into light smoker, moderate smoker and heavy smoker according to smoking index. After detailed history and physical examination SNCV of median and ulnar nerve in upper limb and sural nerve in lower limb was performed. RESULTS: On comparison of SNCV of median and ulnar nerve of upper limb and sural nerve of lower limb between control and diabetic non-smoker only sural nerve of diabetic non smoker showed significant bilateral decrease. There was significant bilateral decrease in SNCV of median and ulnar nerve of diabetic heavy smoker when compared to control and diabetic non smoker. Similarly, SNCV of sural nerve of diabetic heavy smoker was significantly decreased when compared with control, diabetic non-smoker, diabetic light and moderate smoker. A negative and statistically significant correlation was found between SNCV and smoking index. CONCLUSION: Present study indicates that nerves of lower limbs are more susceptible to diabetic assault as compared to upper limb suggesting that long nerves are commonly affected. Also, apart from duration and severity of diabetes, smoking itself is an independent factor for diabetic neuropathy.

Relation between distal motor latency delay and sensory action potential absence of the median nerve in carpal tunnel syndrome.

OBJECTIVE: To elucidate the cutoff value for distal motor latency (DML) at which sensory nerve action potentials (SNAPs) are absent in carpal tunnel syndrome (CTS) patients. METHOD: We examined 157 hands in 129 patients with CTS retrospectively. We classified the patients according to whether SNAPs were successfully obtained. Group A consisted of hands with SNAPs, while Group B consisted of hands without SNAPs. The cutoff value for DML was determined by receiver-operating characteristic curve analysis. We enrolled 130 hands with CTS for the analysis, because measurements were successful in 130 hands for compound muscle action potentials and in 82 hands for SNAPs from a total of 157 hands investigated. RESULTS: A significant correlation was observed between DML and SCV (P<0.0001, R*2=0.40). The most discriminative cutoff value for DML was 7.7ms, resulting in a sensitivity of 79.6% and specificity of 79.3%. CONCLUSION: Cases in which SNAPs are evoked despite a DML longer than 7.7ms should raise suspicion.

Correlation between diabetic lower-extremity arterial disease and diabetic neuropathy in patients with type II diabetes: an exploratory study.

The lower-extremity vascular injuries and neuropathy are the most salient complications of diabetes which could lead to the poor prognosis, especially for the type II diabetes. The lower extremity vascular injuries and neuropathy usually coexist, yet their correlation in the pathogenesis of lower extremity lesions has received little attention in previous studies. To investigate the correlation between the degree of lower-extremity arterial injuries and lower-extremity neurological functional status in patients with type II diabetes, 32 patients with type II diabetes were examined for the mean flow velocity of the femoral artery and popliteal artery of lower extremeties, while the motor nerve conduction velocity (MCV) and sensory nerve conduction velocity (SCV) of the bilateral common peroneal nerve, sural nerve and posterior tibial nerve were simultaneously examined. Results showed that there was moderate correlation between the mean flow velocity of lower-extremity arteries and MCV/SCV. In particular, the MCV of the right tibial nerve was strongly correlated with the average velocity of the right popliteal artery (P < 0.05).

Anterior subcutaneous transposition of the ulnar nerve improves neurological function in patients with cubital tunnel syndrome.

Although several surgical procedures exist for treating cubital tunnel syndrome, the best surgical option remains controversial. To evaluate the efficacy of anterior subcutaneous transposition of the ulnar nerve in patients with moderate to severe cubital tunnel syndrome and to analyze prognostic factors, we retrospectively reviewed 62 patients (65 elbows) diagnosed with cubital tunnel syndrome who underwent anterior subcutaneous transposition. Preoperatively, the initial severity of the disease was evaluated using the McGowan scale as modified by Goldberg: 18 patients (28%) had grade IIA neuropathy, 20 (31%) had grade IIB, and 27 (42%) had grade III. Postoperatively, according to the Wilson & Krout criteria, treatment outcomes were excellent in 38 patients (58%), good in 16 (25%), fair in 7 (11%), and poor in 4 (6%), with an excellent and good rate of 83%. A negative correlation was found between the preoperative McGowan grade and the postoperative Wilson & Krout score. The patients having fair and poor treatment outcomes had more advanced age, lower nerve conduction velocity, and lower action potential amplitude compared with those having excellent and good treatment outcomes. These results suggest that anterior subcutaneous transposition of the ulnar nerve is effective and safe for the treatment of moderate to severe cubital tunnel syndrome, and initial severity, advancing age, and electrophysiological parameters can affect treatment outcome.

Effects of progesterone on neuropathic pain responses in an experimental animal model for peripheral neuropathy in the rat: a behavioral and electrophysiological study.

Progesterone (PROG) is promising as an important protective agent against various injuries to the nervous system. The present study was designed to investigate whether starting PROG administration, when symptomatology is already established, would alleviate the expression of nociceptive behaviors (mechanical allodynia and thermal hyperalgesia) and electrophysiological changes in a chronic constriction injury (CCI) model of neuropathic pain in rats. Male rats were given PROG (1.5, 3, 6 and 12 mg/kg, i.p.) 12 days after CCI induction, and dosing continued daily until day 26. Behavioral tests were done immediately before surgery (day 0) and on days 12, 26, 28, and 35 post-CCI, and were followed by electrophysiological measurements in the last day. PROG at doses of 6 or 12 mg/kg reduced both the thermal hyperalgesia and mechanical allodynia induced by CCI. Electrophysiological data indicated that CCI-induced animals had a remarkable decrement of both compound muscle and nerve action potential amplitudes recorded in the gastrocnemius muscle and sural nerve, respectively. CCI also caused a significant reduction in motor and sensory conduction velocities measured in the sural and tibial nerves, respectively. PROG at doses of 6 or 12 mg/kg induced a significant recovery of all electrophysiological changes. Our data indicated that starting PROG therapy when symptomatology is already established, and continuing it for a sufficient period of time, may have a therapeutic effect. This suggests that PROG may offer new strategies for the treatment of neuropathic pain.

Elucidation of molecular mechanism involved in neuroprotective effect of Coenzyme Q10 in alcohol-induced neuropathic pain.

The aim of the present investigation was to evaluate the effect of Coenzyme Q10 and its combination with vitamin E in alcohol-induced chronic neuropathic pain. Male Wistar rats were orally treated with alcohol (10 g/kg, 35% v/v, b.i.d.) for 10 weeks. Coenzyme Q10 (25, 50, and 100 mg/kg) and vitamin E (100 mg/kg) were coadministered orally for 1 h after ethanol administration for 10 weeks. Various nerve functions, biochemical, and molecular parameters were assessed. Chronic administration of ethanol for 10 weeks resulted significant development of neuropathic pain. Treatment with Coenzyme Q10 (50 and 100 mg/kg) for 10 weeks showed significant and dose dependently increased in level of nociceptive threshold, endogenous antioxidant, and Na,K-ATPase enzyme. Coenzyme Q10 (50 and 100 mg/kg) significantly restored the levels of motor nerve conduction velocity and sensory nerve conduction velocity. It also showed significant decrease in levels of endogenous calcium, oxidative-nitrosative stress, TNF-α, IL-1ß, and IL-4 level. Alteration in protein expression of polymerase gamma (pol γ) was significantly restored the Coenzyme Q10 treatment. The important finding of the study is that, Coenzyme Q10 (100 mg/kg) and α-tocopherol (100 mg/kg) combination-treated rats showed more significant prevention of behavioral, biochemical, and molecular neurotoxic effect of alcohol administration than Coenzyme Q10 or α-tocopherol alone treated group. It is evident from the finding of present investigation that plethora of mechanism including inhibition of oxido-nitrosative stress, release of pro-inflammatory cytokine, modulation of endogenous biomarker, and protection of pol γ protein expression simultaneously orchestrate to exhibits neuroprotective effect of Coenzyme Q10, vitamin E and their combination.

Endoplasmic reticulum stress contributes to prediabetic peripheral neuropathy.

Growing evidence suggests that prediabetes and metabolic syndrome are associated with increased risk for the development of microvascular complications including retinopathy, nephropathy, and, most commonly, peripheral painful neuropathy and/or autonomic neuropathy. The etiology of these disabling neuropathies is unclear, and several clinical and experimental studies implicated obesity, impaired fasting glycemia/impaired glucose tolerance, elevated triglyceride and non-esterified fatty acids, as well as oxidative-nitrative stress. Endoplasmic reticulum stress resulting from abnormal folding of newly synthesized proteins and leading to the impairment of metabolism, transcriptional regulation, and gene expression, is emerging as a key mechanism of metabolic diseases including obesity and diabetes. We evaluated the role for this phenomenon in prediabetic neuropathy using two animal models i.e., Zucker (fa/fa) rats and high-fat diet fed mice which displayed obesity and impaired glucose tolerance in the absence of overt hyperglycemia. Endoplasmic reticulum stress manifest in upregulation of the glucose-regulated proteins BiP/GRP78 and GRP94 of unfolded protein response was identified in the sciatic nerve of Zucker rats. A chemical chaperone, trimethylamine oxide, blunted endoplasmic reticulum stress and alleviated sensory nerve conduction velocity deficit, thermal and mechanical hypoalgesia, and tactile allodynia. A selective inhibitor of eukaryotic initiation factor-2α dephosphorylation, salubrinal, improved glucose intolerance and alleviated peripheral nerve dysfunction in high-fat diet fed mice. Our findings suggest an important role of endoplasmic reticulum stress in the neurobiology of prediabetic peripheral neuropathy, and identify a new therapeutic target.

Entrapment neuropathies and polyneuropathies in joint hypermobility syndrome/Ehlers-Danlos syndrome.

OBJECTIVE: This study aims to investigate the involvement of the peripheral nervous system in Ehlers-Danlos syndromes/hypermobility type patients with particular attention to entrapment syndromes. METHODS: We consecutively enrolled Ehlers-Danlos syndromes/hypermobility type patients. Patients underwent clinical, neurophysiological and ultrasound evaluations. Dynamic ultrasound evaluation was also performed in healthy subjects as control group. RESULTS: Fifteen Ehlers-Danlos syndromes/hypermobility type patients and fifteen healthy subjects were enrolled. Most of patients presented tingling, numbness, cramps in their hands or feet. Clinical evaluation was normal in all patients. One patient was affected with carpal tunnel syndrome and one with ulnar nerve entrapment at elbow. One patient had an increased and hypoechoic ulnar nerve at elbow at ultrasound evaluation. Dynamic ultrasound evaluation of ulnar nerve at elbow showed, in patients, twelve subluxations and three luxations. In the control group dynamic evaluation showed one case of ulnar nerve luxation. CONCLUSION: Statistical analysis showed a significant difference in the occurrence of ulnar nerve subluxation and luxation between patients and control subjects. SIGNIFICANCE: The study shows an inconsistency between symptoms and neurophysiological and ultrasound evidences of focal or diffuse nerve involvement. The high prevalence of ulnar nerve subluxation/luxation at elbow in Ehlers-Danlos syndromes/hypermobility type patients could be explained by the presence of Osborne ligament laxity.

Hand-arm vibration syndrome: clinical characteristics, conventional electrophysiology and quantitative sensory testing.

OBJECTIVE: Workers exposed to vibrating tools may develop hand-arm vibration syndrome (HAVS). We assessed the somatosensory phenotype using quantitative sensory testing (QST) in comparison to electrophysiology to characterize (1) the most sensitive QST parameter for detecting sensory loss, (2) the correlation of QST and electrophysiology, and (3) the frequency of a carpal tunnel syndrome (CTS) in HAVS. METHODS: QST, cold provocation tests, fine motor skills, and median nerve neurography were used. QST included thermal and mechanical detection and pain thresholds. RESULTS: Thirty-two patients were examined (54 ± 11 years, 91% men) at the more affected hand compared to 16 matched controls. Vibration detection threshold was the most sensitive parameter to detect sensory loss that was more pronounced in the sensitivity range of Pacinian (150 Hz, x12) than Meissner's corpuscles (20 Hz, x3). QST (84% abnormal) was more sensitive to detect neural dysfunction than conventional electrophysiology (37% abnormal). Motor (34%) and sensory neurography (25%) were abnormal in HAVS. CTS frequency was not increased (9.4%). CONCLUSION: Findings are consistent with a mechanically-induced, distally pronounced motor and sensory neuropathy independent of CTS. SIGNIFICANCE: HAVS involves a neuropathy predominantly affecting large fibers with a sensory damage related to resonance frequencies of vibrating tools.

Management of diabetic complications: a chemical constituents based approach.

ETHNOPHARMACOLOGICAL RELEVANCE: Long term hyperglycemia leads to development of complications associated with diabetes. Diabetic complications are now a global health problem without effective therapeutic approach. Hyperglycemia and oxidative stress are important components for the development of diabetic complications. Over the past few decades, herbal medicines have attracted much attention as potential therapeutic agents in the prevention and treatment of diabetic complications due to their multiple targets and less toxic side effects. This review aims to assess the current available knowledge of medicinal herbs for attenuation and management of diabetic complications and their underlying mechanisms. MATERIAL AND METHODS: Bibliographic investigation was carried out by scrutinizing classical text books and peer reviewed papers, consulting worldwide accepted scientific databases (SCOPUS, PUBMED, SCIELO, NISCAIR, Google Scholar) to retrieve available published literature. The inclusion criteria for the selection of plants were based upon all medicinal herbs and their active compounds with attributed potentials in relieving diabetic complications. Moreover, plants which have potential effect in ameliorating oxidative stress in diabetic animals have been included. RESULTS: Overall, 238 articles were reviewed for plant literature and out of the reviewed literature, 127 articles were selected for the study. Various medicinal plants/plant extracts containing flavonoids, alkaloids, phenolic compounds, terpenoids, saponins and phytosterol type chemical constituents were found to be effective in the management of diabetic complications. This effect might be attributed to amelioration of persistent hyperglycemia, oxidative stress and modulation of various metabolic pathways involved in the pathogenesis of diabetic complications. CONCLUSION: Screening chemical candidate from herbal medicine might be a promising approach for new drug discovery to treat the diabetic complications. There is still a dire need to explore the mechanism of action of various plant extracts and their toxicity profile and to determine their role in therapy of diabetic complications. Moreover, a perfect rodent model which completely mimics human diabetic complications should be developed.