Comparison of second lumbrical interosseous median and ulnar motor conduction study in population of subjects with idiopathic carpal tunnel syndrome and non-CTS hands-a cross-sectional study

Background: Second lumbrical interosseous (2L-I) median-ulnar motor conduction study across wrist is pivotal in electrodiagnosis of carpal tunnel syndrome (CTS) in different grades of severity. 2L-I Median versus ulnar distal motor latency (DML) difference more than 0.5 milliseconds is used to diagnose median neuropathy at wrist. Other variables of study, namely, 2L DML, compound muscle action potential (CMAP) amplitude, CMAP duration, and conduction velocity (CV) remain less explored with few studies pressing for its role to substantiate CTS diagnosis. Aims and Objectives: Current cross-sectional study aimed to explore role of 2L-I DML, amplitude, duration, and CV in diagnosis of median neuropathy at wrist. Materials and Methods: Total 70, 37 clinically suspected CTS hands and 33 age, height, and weight matched non-CTS hands underwent 2L-I Median Ulnar motor conduction study. Results: Statistically significant difference (P < 0.05) in 2L median DML, CMAP amplitude, duration and CV between CTS and non-CTS hands along with 2L-I Median versus Ulnar DML difference. 2L DML and 2L-I DML difference variables showed better specificity and sensitivity: 83.78 and 93.91, respectively, in diagnosing CTS. Conclusion: We concluded that apart from 2L-I DML difference other variables such as DML, amplitude, duration, and CV may also play substantial role in evaluation of CTS and may be included as part of electrodiagnostic protocol.

Effect of Acupuncture Stimulation on the Long Latency Reflex / 全日本鍼灸学会雑誌

[Objectives] In this study, we examined the effects of acupuncture stimulation on short latency reflexes (SLR) and long latency reflexes (LLR) to determine the site of acupuncture stimulation in modulating motor reflexes. Further, we investigated the relationship between changes in LLR and changes in the N20 somatosensory evoked potential (SEP) component induced by acupuncture stimulation and examined changes in central motor conduction time (CMCT).[Subjects and Methods] Sixteen healthy and right-handed adults (11 males and 5 females; 28.9 ± 6.6 years old; upper limb length 54.9 ± 3.2 cm) participated in this study. The experiments were performed under three conditions: (1) control (no acupuncture stimulation), (2) acupuncture stimulation of right-sided Hegu (LI4), and (3) acupuncture stimulation of left-sided LI4. An acupuncture needle (0.18 mm in diameter) was inserted up to a depth of 10 mm at the right- or left-sided LI4. Electrical stimulation was delivered to the median nerve in the right hand joint at a 120% intensity compared with the threshold to produce an M-wave. SLR and LLR were recorded from the opponens pollicis muscle of the right hand. The frequency and amplitude ratio of SLR (latency, approximately 20-30 ms) and LLR (latency, approximately 40-70 ms) were analyzed. SEP was produced by electrical stimulation delivered to the median nerve. The amplitude from baseline and mean latency of N20 waves were measured. F-wave in the evoked electromyography was evoked by electrical stimulation of the median nerve of the right hand at supramaximal intensity to elicit an M-wave and recorded from the opponens pollicis muscle of the same hand. We analyzed the mean latency and calculated the CMCT using the mean latencies of LLR, N20, F-wave, and M-wave.[Results] The frequency and amplitude ratio of SLR were reduced by acupuncture stimulation of left- and right-sided LI4, respectively. LLR frequency and amplitude ratio were reduced by acupuncture stimulations on either side. A correlation was observed between changes in the LLR amplitude ratio and changes in the N20 SEP amplitude ratio induced by acupuncture stimulation. No effect of acupuncture stimulation was observed on CMCT. [Discussion and Conclusion] SLR is the reflex potential of the spinal cord, and LLR is the motor reflex of the central nervous system via supraspinal pathways. These findings suggest that acupuncture stimulation inhibits motor nerve reflexes via both spinal and supraspinal modulation systems.

The effectiveness of low-frequency transcranial magnetic stimulation for restoring upper limb function after cerebral infarction / 中华物理医学与康复杂志

Objective To compare the effects of repetitive transcranial magnetic stimulation (rTMS) at various low frequencies on upper limb function after cerebral infarction.Methods Fifty patients were randomly assigned to a control group (10 cases),a sham rTMS group (10 cases) or an rTMS group which had three sub-groups treated at 0.25 Hz,0.5 Hz and 0.75 Hz with 10 cases in each.All of the patients were treated with conventional medical treatment and rehabilitation training.The sham and true rTMS groups received rTMS applied over the M1 area of the unaffected hemisphere,5 days per week for 4 weeks.Motor evoked potential (MEP) cortical latency,and central motor conduction time (CMCT) were measured and the Fugl-Meyer assessment (FMA),motricity index (MI) and a Hong Kong functional test for the hemiplegic upper extremity (FTHUE-HK) were evaluated beforehand and at Post 1 after 2 weeks of treatment and Post 2 after 4 weeks of treatment.Results The average CMCT and FMA scores of the control and sham rTMS groups both had improved significantly at Post 2.There was no significant difference in any of the indices between those 2 groups at any time point.At Post 1,the average MEP cortical latencies of the 0.25 Hz and 0.5 Hz subgroups had improved to be significantly better than those of the control and sham rTMS groups.The average CMCTs of the 0.25 Hz and 0.5 Hz rTMS subgroups were significantly shorter after treatment,and significantly better than those of the control and sham rTMS groups.At Post 2,the average MEP cortical latency of all groups except the control group showed significant improvement compared with pre-treatment.The 2 indices of the 0.25 Hz and 0.5 Hz subgroups were again significantly shorter than those of the control and sham rTMS groups,and the average CMCTs were significantly better than that of 0.75 Hz subgroup.At Post 1 the average FMA and MI scores of the rTMS subgroups had all improved significantly.In the 0.25 Hz and 0.5 Hz subgroups the average MI scores were significantly higher than those of the control and sham rTMS groups.The FTHUE-HK scores of those 2 subgroups had also improved significantly.At Post 2,the average FMA and MI scores of all groups and the FTHUE-HK scores of rTMS group had improved significantly.In the 0.25 Hz and 0.5 Hz subgroups,all of the indices were significantly better than in the control and sham rTMS groups.The average FTHUE-HK score of the 0.25 Hz subgroup was significantly superior to that of the 0.75 Hz subgroup.In the 0.75 Hz subgroup the average MI score was significantly higher than in the control and sham rTMS groups.Conclusions rTMS at either 0.25 Hz or 0.5 Hz applied to the unaffected hemisphere provides effective treatment for enhancing the excitability of the motor cortex and the motor function of a paretic upper limb after stroke.Compared with others,the total number of stimulus pulse in 0.25 Hz subgroup was the least,and priority consideration should be given to the frequency of 0.25 Hz when using rTMS in clinical treatment of cerebral infarction.

Anti-GM1 Antibody Associated Acute Motor Conduction Block Neuropathy Presenting With Reversible Conduction Failure

A 57-year-old man developed motor weakness and paresthesia after acute enteritis. Nerve conduction study revealed decreased compound muscle action potentials in median nerves and conduction blocks in ulnar nerves. Serum IgG anti-GM1 antibody was positive. Conduction blocks rapidly disappeared through sequential studies, which are defined as reversible conduction failure (RCF). This study represents anti-GM1 antibody-associated acute motor conduction block neuropathy based on RCF. We underline that serial nerve conduction studies might be required for characterization of clinical and electrophysiological features.

Effect of low-frequency suprathreshold repetitive transcranial magnetic stimulation of the unaffected hemisphere on recovery of motor function in patients with acute stroke / 中华神经医学杂志

Objective To study the effect of low-frequency suprathreshold repetitive transcranial magnetic stimulation (rTMS) of the unaffected hemisphere on recovery of motor function in patients with acute stroke. Methods A total of 26 patients with middle cerebral artery territory infarction were randomly assigned to unaffected hemisphere stimulation group and control group (not receiving any stimulation,n=13).The patients in the stimulation group were treated with rTMS 3 to 5 d after the onset of symptoms with the frequency of 1 Hz and 70％ of the intensity (about 2.1T actual output) and the 1200 pulses per day for 10 consecutive d.The motor evoked potential (MEP) latency,central motor conduction time (CMCT),scores of National Institutes of Health Stroke Scale (NIHSS) and modified Barthel index (MBI) of the affected brain region were recorded on the 1 st of experiment (before the treatment),10 and 40 d after treatment. Results The scores of clinical futction scale and neuroelectrophysiologic parameters before treatment had no statistical significance between the 2 groups (P＞0.05).The scores of clinical function scale after the treatment in the 2 groups were obviously higher than those before treatment (P＜0.05). And the improvement of motor function in the unaffected hemisphere stimulation group was statistically obvious as compared with that in the control group (P＜0.05):the score of NIHSS and the MBI in the stimulation group were obviously higher than those in the control group (P＜0.05).The neuroelectricity physiological indexs in the 2 groups after treatment gained improvement in comparision to those before treatment:the MEP latency on the 40th d of treatment and CMCT on the 10th and 40th d of treatment in the unaffected hemisphere stimulation group was significantly different as compared with those before treatment (P＜0.05); the CMCT on the 10th and 40th d of treatment in the unaffected hemisphere stimulation group was shorter as compared with that in the control group. Conclusion The frequency of 1 Hz and 70％ of the intensity (about 2.1T actual output) in rTMS of the unaffected hemisphere can shorten CMCT and improve the motor function in patients with acute stroke.

Corticospinal Tract and Pontocerebellar Fiber of Central Pontine Myelinolysis

Central pontine myelinolysis is a rare neurologic disorder that is defined by demyelination of longitudinally descending tracts and transversly crossing fibers in the basis pontis. Frequently observed clinical manifestations of this disorder include sudden weakness, dysphagia, loss of consciouness and locked-in syndrome. However, there have been a few studies that reported a benign course of this disease, which include cerebellar signs, such as ataxia, intention tremor, and dysarthria. Here we report on a 53-year-old male with a history of liver cirrhosis who showed the cerebellar type of central pontine myelinolysis. The patient was diagnosed with central pontine myelinolysis based on clinical presentations and magnetic resonance imaging findings after a liver transplantation. Conventional magenetic resonance imaging (MRI) revealed the preservation of the corticospinal tract and abnormal pontocerebellar fibers. However, these findings were not sufficient to define the pathophysiology of our patient. Electrophysiologic analysis and diffusion tensor imaging (DTI) were performed to investigate cerebellar signs in this case. Delayed central motor conduction time (CMCT) to the tibialis anterior muscle with transcranial magnetic stimulation (TMS) was observed, which indicated demyelination of the corticospinal tract. Also, diffusion tensor imaging showed abnormal pontocerebellar fibers, which might have been caused by cerebellar dysfunction in our patient. A combination of TMS and DTI was also used to determine the pathophysiology of this disease.

Effects of perineurial block of sciatic nerve with different concentrations of alcohol on structure and function of the nerve and its innervated muscles in rats / 中华物理医学与康复杂志

Objective To observe the concentration effects of alcohol in perineurial block on the structure and function of sciatic nerve and it's innervated muscles in rats so as to provide the basis for clinical application of chemical neurolysis.Methods One hundred and fifty female Sprague-Dawley rats were used and randomly assigned into a blank group(BG,n =6),a control group(CG,n =36),a 50％ alcohol group(50G,n =36),a 75％ alcohol group(75G,n =36)and a 99.9％ alcohol group(99.9G,n =36).The CG received physiological saline injection,the 50G,75G,99.9G received corresponding concentrations alcohol perineurial block,respectively.Changes of motor function was assessed,electrophysiological and histomorphological observations of sciatic nerve and its innervated muscles were conducted before and at 24 h,72 h,1 week,4 week,12 week after block.Results(① Hypokinesia and decrease of motor conduction velocity(MCV)were observed at 24 h after block,and peaked at 72 h after block; at 1 week after block,the motor function and MCV improved,the improvement persisted to the 12th week (P ＜ 0.05); but at the 12th week,MCV was still slower than that before block(P ＜ 0.01).②There were significant differences with regard to motot function and MCV of sciatic nerve among 99.9G and the other groups at e ery time point after block(P ＜0.05); ③ Reversible dengeneration of sciatic nerve and hind limb muscle,nonreversible necrosis of muscle occurred more seriously with the increase of alcohol concentration,and the cicatrization in 99.9G was more obvious than that in 50G and 75G at the 12th week; ④Structural lesion of sciatic nerve occurred at 24 h after block and peaked at the 72th h,myelinated axonal sprouts appeared at 1 week after block and persisted to the 12th weck.Conclusions ① The effects of 99.9 ％ alcohol perineural block on the structural lesion,motor function and MCV of sciatic nerve and its related muscle were more obvious than those of 50％ and 75％ alcohol; ② The destructive effect of alcohol block would maintain more than 12 week and neural restoration would maintain more than 12 weeks too.

Effect of Ultrashort Wave Therapy on Motor Conduction Velocity and Expression of Vascular Endothelial Growth Factor of Damaged Movement Neurons in Rats with Sciatic Nerve Injury / 中国康复理论与实践

@#Objective To investigate the effect of ultrashort wave therapy on motor conduction velocity (MCV) and expression of vascular endothelial growth factor (VEGF) in rats with sciatic nerve injury.MethodsThe models of peripheral nerve injury were established by forceps clip of sciatic nerve and then a total of 60 SD rats were divided randomly into three groups, including experimental group (n=24), control group (n=24) and sham operation group(n=12). The rats of experimental group were treated by ultrashort wave therapy after operation. The injured sciatic nerve and spinal cord in waist were sampled at the 1st，2nd，4th，6th week respectively after operation and were observed by electrophysiology and immunohistochemistry.ResultsAfter operation，the MCV of sciatic nerve in both experimental group rats and control group rats is zero in 1st week. Since 2nd week，the MCV of sciatic nerve in rats of both two groups began to arise and the MCV of injuried sciatic nerve in rats of experimental group was higher than that in the control group (P<0.05). In injured spinal cord motoneuron，the Integrated Optical Density(IOD) of VEGF in experimental group was higher than that in the control group (P<0.05).ConclusionUltrashort wave therapy could increase the value of MCV of sciatic nerve and the expression of VEGF in spinal cord in rats,and so it could protect the injured peripheral nerve.

Anatomical Evaluation of Ulnar Nerve according to the Elbow Position

OBJECTIVE: To investigate the anatomy of the ulnar nerve according to the degree of elbow flexion and to obtain optimal elbow position for ulnar nerve conduction study. METHODS: Eleven elbows in nine cadavers were dissected. We estimated the 10 cm elbow segment to be the distance between 2 points, 4 cm distal and 6 cm proximal to the center of the cubital tunnel, which was determined to be the halfway point between the medial epicondyle and olecranon with elbow position in extension and 45o, 90o, 135o flexion. Anatomical measurements of the actual length of ulnar nerve, distance between medial epicondyle and ulnar nerve, and distance between medial epicondyle and olecranon were obtained in each position. The actual length of the ulnar nerve was measured between two points of the ulnar nerve closest to the landmarks of the estimated 10 cm with flexible ligature. RESULTS: The actual lengths of ulnar nerve were 10.23 cm, 10.00 cm, 9.44 cm, and 9.08 cm in elbow extension, and 45o, 90o, 135o flexion, respectively. The difference between actual length and estimated lengths were least in 45o elbow flexion (p=0.0001). The distance between medial epicondyle and olecranon increased with increasing elbow flexion (p=0.0001). However, there was no difference in the distance between medial epicondyle and ulnar regardless of the elbow position. As a result, the ulnar nerve seemed to have migrated anteriorly in the cubital tunnel with increasing elbow flexion. CONCLUSION: This study suggest that the optimal angle in ulnar nerve conduction study would be 45o flexion, under the condition that the distance measurement is through the halfway point between the medial epicondyle and olecranon.

A comparative study of motor conduction velocity and F-wave parameters between diabetes mellitus and healthy subjects / 中国糖尿病杂志

0 1). (4)75 2% of all the patients in DM group showed one or more abnormalities in MCV or F wave parameters, and electrophysiological abnormalitis correlated with, or precede to clinical findings in 175 of 190 patients (92 1%). Conclusion MCV and F wave parameters are sensitive measures for detection of DPN. Among these parameters, FwPL, F MIPL from all the four nerves are the most sensitive. To improve diagnostic accuracy, all the MCV and F wave parameters recorded should be considered.

The Blink Reflex in Diabetic Patients

OBJECTIVE: To assess the facial and trigeminal nerve involvement in diabetic patients using blink reflex study and direct facial motor conduction study. METHOD: The subjects were 397 diabetic patients and 34 normal controls. Diabetic patients were subdivided into two groups based on the findings of nerve conduction studies of limb nerves.: Group I, patients with diabetic polyneuropathy; Group II, patients without diabetic polyneuropathy. The blink reflexes and direct facial motor responses and R1 latency/direct response latency (R/D) ratio were obtained in all the subjects. R1 latency was correlated to the findings of nerve conduction studies of limb nerves. RESULTS: 1) R1 latencies or R2 latencies were abnormally prolonged in 22.4% of Group I, 3.3% of Group II, and direct facial responses were abnormal in 11.8% of Group I, 2% of Group II. 2) There were no significant differences in R/D ratio between the two groups. 3) These findings suggest that not only the facial nerve, but also the trigeminal nerve or brain stem could be affected in diabetic patients with polyneuropathy. CONCLUSION: In diabetic patients, blink reflex can provide useful information in determining the degree and distribution of cranial nerve and brain stem lesions.

Transcranial Magnetic Stimulation in Parkinson's disease

BACKGROUND: Parkinson's disease (PD) is one of the most common movement disorders, yet the pathophysiology of its signs is not clear. A transcranial magnetic stimulation (TMS) was used to measure the amplitude and latency of the motor evoked potential(MEP) by stimulation of the corticomotoneuronal descending system. By means of this simple and nontraumatic technique we intended to analyze the abnormal motor signs of PD. METHODS: We studied 20 PD patients aged 35 to 78 years and 12 normal persons aged 37 to 67 years. Hoehn-Yahr scale of PD patients were as follows: I, 4 patients ; II ,11 patients ; III, 4 patients ; IV, 1 patient. The responses were was recorded from abductor polli-cis brevis (APB) muscles and abductor hallucis (AH) muscles. The TMS was performed on the cervical spine and ver-tex for APB muscle and on the lumbar spine and C3 or C4 for bilateral AH muscles. The responses were recorded with both target muscles relaxed and slightly contracted. We measured the threshold, latency, and amplitude of each MEP. The central motor conduction time (CMCT) was calculated by the latency difference between cortical stimulation and cervical or lumbar stimulation. RESULTS: The central motor conduction times were shorter in PD patients (P < 0.05) compared with normal subjects but there were no differences in motor evoked potentials. Also, PD patients showed a significant increase of stimulation threshold in the facilitation state. CONCLUSIONS: These results may suggest that con-trol of excitability of the motor system is abnormal in PD patients.

Median Motor Nerve Conduction and H-reflex Studies in Premature Infants

Many factors have been identified which to affect the rate of propagation of impulses along motor fibers. These include temperature changes around the nerve, diameter of the axon, degree of myelinization, age of infants, and local environment of the nerve. Motor nerve conduction velocity and Hoffman's reflex latency have been used to assess the degree of myelination and maturation of the nervous system. The conduction velocities in infants of a short gestational age are significantly lower than those of the fullterm infants. The extrauterine myelination and maturation might increase nerve conduction velocity. We measure the median motor nerve conduction velocity, compound muscle action potentials amplitude and H-reflex latency of premature infants to determine the neurological maturation after birth. The premature infants with gestational age above 37 weeks have a significantly higher conduction velocity and a shorter H-reflex latency than those of gestational age below 37 weeks. The premature infants with weight over 2.5 kg have a significantly higher conduction velocity, larger compound muscle action potentials amplitude and a shorter H-reflex latency than those of weight below 2.5 kg. And there is a statistically significant negative correlation of the H-reflex latency with the postmenstrual age. The determination of motor nerve conduction velocities and H-reflex latencies seem to be an additional method in assessing the degree of maturity in infants after birth.

Normal values of Motor Evoked Potentials by Transcranial Magnetic Stimulation

Electrical stimulation has been used for evaluating central motor system and deep portion of peripheral nerve, but it was painful. And then magnetic stimulation was introduced recently and used widely because it was painless and easily repeated, compared to electrical stimulation. This study was undertaken in order to obtain normal valued of motor evoked potentials by transcranial magnetic stimulation. Ninety-two volunteers, free of neurological disease, were tested with Medelec Magstim model 200 and Medelec MIstral. There were 55 male and 37 female, ranging in height from 130 to 180 centimeter, with a mean height of 165.9 centimeter, in age from 13 to 70 years, with a mean age of 34 years. Transcranial magnetic stimulation cause contralateral hand and foot muscle responses, and the resultant motor evoked potentials can be recorded. Stimulating sites were near vertex in head, Erb's point in cervical region and L45 interspace in lumbar region. Recording sites wre abductor pollicis brevis(APB) in hand and abductor hallucis(AH) in foot. Our results were as follow ; 1) Latency between head and contralateral APB was 20.9+/-1.5ms, latency between cervical region and ipsilateral APB was 11.7+/-1.1ms, and there-by CMCT was 9.2+/-1.1ms. 2) Latency between head and contralateral AH was 39.0+/-2.6ms, latency between lumbar region and ipsilateral AH was 20.9+/-2.1ms, and there-by CMCT was 1.8+/-2.0ms. 3) Latency was statistically well correlated with subject height, but not CMCT. 4) There was no statistical significance, between male and female, right and left side, among age group, in latency and CMCT. 5) By voluntary muscle contractions, latency was shortened and amplitude was increased on vertex stimulation, but not hanged on stimulation of cervical and lumbar region. 6) By incraesing stimulus intensity, latency was shortened and amplitude was increased on vertex stimulation, but amplitude only was increased on stimulation of cervical region.

A Study of Motor Conduction Velocity of Radial Nerve: Comparision of Proximal and Distal Segments / 대한정형외과학회잡지

The usage of electromyography is customized in the diagnosis of the neuromuscular disorder and the determination of motor conduction velocity is important in the diagnosis of the peripheral nerve lesion and in the posing of the site and severity of nerve damage. Although the radial nerve is frequently involved in generalized neuropathy and in entrapment syndrome, relatively fewer reports have appeared in the literature regarding the radial nerve. The purpose of this study is to determine the normal data of the motor conduction velocity of the proximal and distal segments of the radial nerve. The radial nerve fibers supplying the extensor indicis muscls muscle was stimulated at Erb's point, above the elbow and in the distal forearm and its muscle action potential was sampled. Seventy-four radial nerve were studied in thirty-seven healthy young subjects. The results obtained were as follows; 1. The mean proximal velocity was 70.7±6.8m/sec and the mean distal velocity was 57.6±4.3m/sec. 2. In any case tested, the proximal velcity was over 55m/sec. 3. The proximal velocity was faster than the distal velocity and the mean difference was 13.1m/sec In only 7 of the 74 nerves tested, the proximal velocity was slower than the distal velocity and the difference of Sm/sec was the most reversal. 4. The velocity in dominant limb was faster than that in nondominant limb. 5. There were no significant difference between the sexes.