BACKGROUNDFew studies have focused on peripheral nerve conduction during exposure to microgravity. The -6° head-down tilt (HDT) comprises an experimental model used to simulate the space flight environment. This study investigated nerve conduction characteristics of rhesus monkeys before and after prolonged exposure to HDT.

METHODSSix rhesus monkeys (3-4 years old) were tilted backward 6° from the horizontal. Nerve conduction studies (NCSs) were performed on the median, ulnar, tibial, and fibular motor nerves. Analysis of variance with a randomized block design was conducted to compare the differences in the NCS before and 7, 21, and 42 days after the -6° HDT.

RESULTSThe proximal amplitude of the CMAP of the median nerve was significantly decreased at 21 and 42 days of HDT compared with the amplitude before HDT (4.38 ± 2.83 vs. 8.40 ± 2.66 mV, F = 4.85, P = 0.013 and 3.30 ± 2.70 vs. 8.40 ± 2.66 mV, F = 5.93, P = 0.004, respectively). The distal amplitude of the CMAP of the median nerve was significantly decreased at 7, 21, and 42 days of HDT compared with the amplitude before HDT (7.28 ± 1.27 vs. 10.25 ± 3.40 mV, F = 4.03, P = 0.039; 5.05 ± 2.01 vs. 10.25 ± 3.40 mV, F = 6.25, P = 0.04; and 3.95 ± 2.79 vs. 10.25 ± 3.40 mV, F = 7.35, P = 0.01; respectively). The proximal amplitude of the CMAP of the tibial nerve was significantly decreased at 42 days of HDT compared with the amplitude before HDT (6.14 ± 1.94 vs. 11.87 ± 3.19 mV, F = 5.02, P = 0.039).

CONCLUSIONSThis study demonstrates that the compound muscle action potential amplitudes of nerves are decreased under simulated microgravity in rhesus monkeys. Moreover, rhesus monkeys exposed to HDT might be served as an experimental model for the study of NCS under microgravity.

Action Potentials ; physiology ; Animals ; Female ; Head-Down Tilt ; physiology ; Macaca mulatta ; Male ; Neural Conduction ; physiology ; Weightlessness Simulation

BACKGROUNDThe appropriate elbow position of short-segment nerve conduction study (SSNCS) to diagnose cubital tunnel syndrome (CubTS) is still controversial. The goal of this study was to determine the effect of different elbow positions at full extension and 70° flexion on SSNCS in CubTS.

METHODSIn this cross-sectional study, the clinical data of seventy elbows from 59 CubTS patients between September, 2011 and December, 2014 in the Peking University First Hospital were included as CubTS group. Moreover, thirty healthy volunteers were included as the healthy group. SSNCS were conducted in all subjects at elbow full extension and 70° elbow flexion. Paired nonparametric test, bivariate correlation, Bland-Altman, and Chi-squared test analysis were used to compare the effectiveness of elbow full extension and 70° flexion elbow positions on SSNCS in CubTS patients.

RESULTSData of upper limit was calculated from healthy group, and abnormal latency was judged accordingly. CubTS group's latency and compound muscle action potential (CMAP) of each segment at 70° elbow flexion by SSNCS was compared with full extension position, no statistically significant difference were found (all P > 0.05). Latency and CMAP of each segment at elbow full extension and 70° flexion were correlated (all P < 0.01), except the latency of segment of 4 cm to 6 cm above elbow (P = 0.43), and the latency (P = 0.15) and the CMAP (P = 0.06) of segment of 2 cm to 4 cm below elbow. Bivariate correlation and Bland-Altman analysis proved the correlation between elbow full extension and 70° flexion. Especially in segments across the elbow (2 cm above the elbow and 2 cm below it), latency at elbow full extension and 70° flexion were strong direct associated (r = 0.83, P < 0.01; r = 0.55, P < 0.01), and so did the CMAP (r = 0.49, P < 0.01; r = 0.72, P < 0.01). There was no statistically significant difference in abnormality of each segment at full extension as measured by SSNCS compared with that at 70° flexion (P > 0.05, respectively).

CONCLUSIONSThere was no statistically significant difference in the diagnosis of CubTS with the elbow at full extension compared with that at 70° flexion during SSNCS. We suggest that elbow positon at full extension can also be used during SSNCS.

Action Potentials ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Cross-Sectional Studies ; Cubital Tunnel Syndrome ; physiopathology ; Elbow ; Female ; Humans ; Male ; Middle Aged ; Neural Conduction ; physiology

BACKGROUNDDysfunctional spinal circuit may play a role in the pathophysiology of amyotrophic lateral sclerosis (ALS). The purpose of this study was to use F waves for assessment of segmental motoneuronal excitability following upper motor neuron (UMN) dysfunctions in ALS.

METHODSWe studied the F waves of 152 ulnar nerves recorded from abductor digiti minimi in 82 patients with ALS. Two groups of hands were defined based on the presence or absence of pyramidal signs in the same upper limb. The group with pyramidal signs in the upper limbs was designated as the P group, and the group without pyramidal signs in the upper limbs was designated as the NP group.

RESULTSThe mean (P < 0.001), median (P < 0.001) and maximum (P = 0.035) F wave amplitudes, mean (P < 0.001), median (P < 0.001) and maximum (P = 0.003) F/M amplitude ratio, index repeating neuron (P < 0.001) and index repeater F waves (P < 0.001) of the P group were significantly increased compared with the NP group. No significant differences were identified for F wave chronodispersion (P = 0.628), mean F wave latency (P = 0.151), minimum F wave latency (P = 0.211), maximum F wave latency (P = 0.199), F wave persistence (P = 0.738), F wave duration (P = 0.152), F wave conduction velocity (P = 0.813) and number of giant F waves (P = 0.072) between the two groups.

CONCLUSIONSIn this study, increased F wave amplitude, F/M amplitude ratio and number of repeater F waves reflected enhanced segmental motoneuronal excitability following UMN dysfunctions in ALS.

Adult ; Aged ; Amyotrophic Lateral Sclerosis ; physiopathology ; Female ; Humans ; Male ; Middle Aged ; Motor Neuron Disease ; physiopathology ; Motor Neurons ; physiology ; Neural Conduction ; physiology ; Ulnar Nerve ; physiology

BACKGROUNDTo study lesions' location and prognosis of cubital tunnel syndrome (CubTS) by routine motor nerve conduction studies (MNCSs) and short-segment nerve conduction studies (SSNCSs, inching test).

METHODSThirty healthy subjects were included and 60 ulnar nerves were studied by inching studies for normal values. Sixty-six patients who diagnosed CubTS clinically were performed bilaterally by routine MNCSs and SSNCSs. Follow-up for 1-year, the information of brief complaints, clinical symptoms, and physical examination were collected.

RESULTSSixty-six patients were included, 88 of nerves was abnormal by MNCS, while 105 was abnormal by the inching studies. Medial epicondyle to 2 cm above medial epicondyle is the most common segment to be detected abnormally (59.09%), P < 0.01. Twenty-two patients were followed-up, 17 patients' symptoms were improved. Most of the patients were treated with drugs and modification of bad habits.

CONCLUSIONS(1) SSNCSs can detect lesions of compressive neuropathy in CubTS more precisely than the routine motor conduction studies. (2) SSNCSs can diagnose CubTS more sensitively than routine motor conduction studies. (3) In this study, we found that medial epicondyle to 2 cm above the medial epicondyle is the most vulnerable place that the ulnar nerve compressed. (4) The patients had a better prognosis who were abnormal in motor nerve conduction time only, but not amplitude in compressed lesions than those who were abnormal both in velocity and amplitude. Our study suggests that SSNCSs is a practical method in detecting ulnar nerve compressed neuropathy, and sensitive in diagnosing CubTS. The compound muscle action potentials by SSNCSs may predict prognosis of CubTS.

Adult ; Aged ; Cubital Tunnel Syndrome ; physiopathology ; Electromyography ; Electrophysiology ; Female ; Humans ; Male ; Middle Aged ; Neural Conduction ; physiology ; Ulnar Nerve ; physiology

BACKGROUNDIn amyotrophic lateral sclerosis (ALS), repeater F waves are increased. Accurate assessment of repeater F waves requires an adequate sample size.

METHODSWe studied the F waves of left ulnar nerves in ALS patients. Based on the presence or absence of pyramidal signs in the left upper limb, the ALS patients were divided into two groups: One group with pyramidal signs designated as P group and the other without pyramidal signs designated as NP group. The Index repeating neurons (RN) and Index repeater F waves (Freps) were compared among the P, NP and control groups following 20 and 100 stimuli respectively. For each group, the Index RN and Index Freps obtained from 20 and 100 stimuli were compared.

RESULTSIn the P group, the Index RN (P = 0.004) and Index Freps (P = 0.001) obtained from 100 stimuli were significantly higher than from 20 stimuli. For F waves obtained from 20 stimuli, no significant differences were identified between the P and NP groups for Index RN (P = 0.052) and Index Freps (P = 0.079); The Index RN (P < 0.001) and Index Freps (P < 0.001) of the P group were significantly higher than the control group; The Index RN (P = 0.002) of the NP group was significantly higher than the control group. For F waves obtained from 100 stimuli, the Index RN (P < 0.001) and Index Freps (P < 0.001) of the P group were significantly higher than the NP group; The Index RN (P < 0.001) and Index Freps (P < 0.001) of the P and NP groups were significantly higher than the control group.

CONCLUSIONSIncreased repeater F waves reflect increased excitability of motor neuron pool and indicate upper motor neuron dysfunction in ALS. For an accurate evaluation of repeater F waves in ALS patients especially those with moderate to severe muscle atrophy, 100 stimuli would be required.

Adult ; Amyotrophic Lateral Sclerosis ; pathology ; physiopathology ; Female ; Humans ; Male ; Middle Aged ; Motor Neurons ; physiology ; Neural Conduction ; physiology ; Sample Size

OBJECTIVETo study the role of proximal nerve stimulation at Erb point in the early diagnosis of Guillain-Barré syndrome (GBS) in children.

METHODSThirty-two children who were diagnosed with GBS between October 2013 and December 2014 received neurophysiological examination. Thirty healthy children were used as controls. Compound muscle action potentials and distal motor latency of the median and ulnar nerves were determined and analyzed after nerve stimulation at the wrist, elbow, and Erb point in the two groups. Moreover, F-wave latency of the median nerve and H-reflex latency of the tibial nerve were measured and analyzed in the two groups.

RESULTSThe F-wave and H-reflex latencies were significantly longer in the patient group than in the control group (P<0.05). In thirty-two patients, the numbers of patients with abnormal amplitude, abnormal latency, and conduction block at Erb's point were 24 (75%), 22 (69%), and 20 (62%), respectively. The patient group had significantly lower amplitudes but significantly longer latencies of the ulnar and median nerves at Erb point than the control group (P<0.05). There were no significant differences in the amplitudes and latencies at the wrist and elbow between the two groups (P>0.05).

CONCLUSIONSThe nerve stimulation at Erb point holds promise as a routine examination for the early diagnosis of GBS.

Adolescent ; Child ; Early Diagnosis ; Electrodiagnosis ; methods ; Female ; Guillain-Barre Syndrome ; diagnosis ; physiopathology ; H-Reflex ; Humans ; Male ; Neural Conduction ; physiology ; Reaction Time

There have been many attempts for regeneration of peripheral nerve injury. In this study, we examined the in vivo effects of non-differentiated and neuronal differentiated adipose-derived stem cells (ADSCs) in inducing the neuronal regeneration in the Sprague-Dawley (SD) rats undergoing nerve defect bridged with the PCL nanotubes. Then, we performed immunohistochemical and histopathologic examinations, as well as the electromyography, in three groups: the control group (14 sciatic nerves transplanted with the PCL nanotube scaffold), the experimental group I (14 sciatic nerves with the non-differentiated ADSCs at a density of 7x105 cells/0.1 mL) and the experimental group II (14 sciatic nerves with the neuronal differentiated ADSCs at 7x105 cells/0.1 mL). Six weeks postoperatively, the degree of the neuronal induction and that of immunoreactivity to nestin, MAP-2 and GFAP was significantly higher in the experimental group I and II as compared with the control group. In addition, the nerve conduction velocity (NCV) was significantly higher in the experimental group I and II as compared with the control group (P=0.021 and P=0.020, respectively). On the other hand, there was no significant difference in the NCV between the two experimental groups (P>0.05). Thus, our results will contribute to treating patients with peripheral nerve defects using PCL nanotubes with ADSCs.
Adipose Tissue/cytology ; Animals ; Cell Differentiation ; Electromyography ; Male ; Nanotubes ; *Nerve Regeneration ; Nerve Tissue Proteins/immunology ; Nestin/immunology ; Neural Conduction/physiology ; Peripheral Nerve Injuries/*surgery ; Phosphoprotein Phosphatases/immunology ; Polyesters/*therapeutic use ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve/injuries/surgery ; Stem Cell Transplantation/*methods ; Stem Cells/*cytology ; Tissue Engineering/methods

OBJECTIVETo observe the effects of electroacupuncture on force-displacement value (FDV) of muscle state and electrophysiology of the muscle in rabbits with lumbar nerve root compression.

METHODSThirty New Zealand white rabbits were randomly divided into a control, a model, an electro-acupuncture acupoints (EAA), a medication, and an electro-acupuncture un-acupoints (EAU) group. All rabbits except those in the control group were subject to modeling (surgical lumbar nerve root compression). The control group was sham-operated without nerve root compression. The EAA group received electro-acupuncture at bilateral Shenshu (BL23) and Dachangshu (BL25) that were located 1.5 cun lateral to the posterior midline on the lower border of the spinous process of the 2nd and 4th lumbar vertebra, respectively. The EA was 15 mm deep and the frequency was 2 Hz. Each session lasted for 20 min per day for a total of 14 times. The medication group was treated with Loxoprofen sodium by gastrogavage at 4 mg/kg per day for 14 days. The EAU group received electro-acupuncture identical to the EAA group with regard to the treatment frequency and duration except a different acupoint at the tip of rabbit tail. Muscle states were determined by measuring FDVs of the bilateral biceps femoris using the Myotonometer® fast muscle state detector. Meanwhile, the prolonged and non-prolonged insertion potentials were measured by electromyography before and after modeling and after treatment. Latency, amplitude (Amp) of evoked potential, motor nerve conduction velocity (MNCV) were also determined after treatment.

RESULTS(1) After modeling, FDVs of right side activation (RSA, P=0.003) and right side relaxation (RSR) in the model group (P=0.000) were significantly decreased in comparison to the control group. The number of rabbits with non-prolonged insertion potentials in the model group was also significantly decreased (P=0.015) in comparison to the control group. (2) After treatment, FDVs of RSR were significantly increased in the EAA (P=0.000) and medication groups (P=0.018) in comparison to the model group. The increase in FDVs of RSR in the EAA group was significantly higher than that in EAU (P=0.000) and medication groups (P=0.002). MNCV in the model group was reduced compared with the control group (P=0.000). The reduction in MNCV after modeling was reversed in the EAA group (P=0.000) and medication group (P=0.008) after treatment and the increases were significant in both treatment groups in comparison to the model group. The EAA group had a greater MNCV recovery than the medication group (P=0.022).

CONCLUSIONElectro-acupuncture could improve the rehabilitation and regeneration of FDVs and the electrophysiology index of the muscle with nerve control impairment.

Animals ; Electroacupuncture ; Electromyography ; Electrophysiological Phenomena ; Evoked Potentials ; physiology ; Lumbar Vertebrae ; physiopathology ; Motor Neurons ; physiology ; Muscles ; physiopathology ; Neural Conduction ; physiology ; Rabbits ; Radiculopathy ; physiopathology ; therapy

OBJECTIVETo investigate the clinical and electrophysiological characteristics and prognosis of acute motor axonal neuropathy (AMAN) in children in South China.

METHODSThe clinical and electrophysiological data of 6 children with AMAN was analyzed, and they were followed up.

RESULTSThe mean age of onset was 4.4 years. Most patients came from rural areas and 5 cases had a history of prodromal infection. There were no seasonal differences in clinical onset among the patients. The most common first symptom was muscle weakness, and the mean time from onset to the most severe disease status was 4.2 days. Nerve conduction test results revealed that all patients showed significantly lower amplitude of motor nerve action potential, only 22.3%-73.4% of the lower limit of normal. Injury to the nerves of distal extremities was more serious than injury to the nerves of proximal extremities (P<0.05), while there was no significant difference in the injury to the nerves of upper and lower extremities (P>0.05). Motor nerve conduction velocity and sensory nerve conduction velocity were normal. All patients received intravenous immunoglobulin (IVIG). Of the 6 AMAN patients, 4 could walk independently after a follow-up of 3 months to 1 year.

CONCLUSIONSAMAN in children occurs mostly in rural areas. There is no seasonal difference in the clinical onset of the disease. Muscle weakness is the most common first symptom and the worst status of AMAN appears in the early stage of the disease. Electrophysiological examination provides important information for the diagnosis of AMAN. Some children with AMAN regain the ability to walk independently 1 year after onset. Early application of IVIG treatment may help recovery of neural function.

Child ; Child, Preschool ; Female ; Guillain-Barre Syndrome ; drug therapy ; immunology ; physiopathology ; Humans ; Immunoglobulins, Intravenous ; therapeutic use ; Infant ; Male ; Neural Conduction ; physiology ; Prognosis

In this research, we compared the visual neuron responses for LGN, A18 and PMLS of old and young cats with extracellular single-neuron recording techniques. We used firing rate vector to characterize information, and response irregularity of cells to evaluate the degeneration of visual characters. Response irregularity is characterized by means of the two coefficients of variation of firing rate vectors: Cv and Cv2. We found that there was no significant change of the response irregularity in LGN areas during the aging process from young to old cats. But in the other two areas, neurons of old cats exhibited significantly larger response irregularity than those of young cats. The result indicated that the information processing function of advanced visual cortex was impaired by aging. This result also provids a reference for the research of the other neuronal system changes during aging process.
Action Potentials ; physiology ; Aging ; physiology ; Animals ; Cats ; Neural Conduction ; Neurons ; physiology ; Visual Cortex ; physiology