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).

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.

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.

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.