By detection and analysis of neuro-information from amputee in experiments, a research on the correlations of three main nerves (median nerve, radial nerve and ulnar nerve), on the patterns for discharging information, and on the mechanics about how neuro-information dominates movements was performed. These researches would contribute to the development of neuroprosthesis.
Adult ; Amputation ; Amputees ; Arm ; Artificial Limbs ; Humans ; Male ; Median Nerve ; physiology ; Microelectrodes ; Movement ; physiology ; Radial Nerve ; physiology ; Ulnar Nerve ; physiology

The classical cable function has been used to represent the response of peripheral nerves stimulated by external parallel electric field. Experiments show that peripheral nerves can be activated by perpendicular electric field induced by magnetic pulses, indicating that the activation mechanism needs to be thoroughly investigated. Several excitation properties of peripheral nerves in transverse-field were explored in the present paper. With a human's median nerve in vivo, stimulation threshold, excitation position and the relation between excitation threshold and fiber's radius were studied. The relation between stimulation threshold and stimulation duration was researched with sciatic nerves from toad in vitro. The experimental results verify that the modified cable function is much efficient than the classical cable function. The research will improve the nerve magnetic stimulating technique and be beneficial to further application.
Animals ; Bufo bufo ; Electric Stimulation ; Electromagnetic Fields ; Electrophysiology ; Humans ; Magnetics ; Median Nerve ; physiology ; Peripheral Nerves ; physiology ; Sciatic Nerve ; physiology

Measurement of motor nerve conduction velocity(MNCV) of the median and peroneal nerves was performed in 79 normal fullterm newborn infants and children up through the age of 329 weeks. They were divided into eight groups by age. The following study was undertaken to obtain the mean +/- S.D. and the regression equation of Y (MNCV) on X (age). The MNCV values of each group were compared with those of normal adults.
Child ; Child, Preschool ; Human ; Infant ; Infant, Newborn ; Median Nerve/physiology ; Motor Neurons/physiology* ; Nerve Fibers/physiology ; Neural Conduction* ; Peroneal Nerve/physiology

Sensory evoked potential (SEP) studies have contributed to the greater accuracy of diagnosis and evaluation in neuropathy. Normal values of SEP serve as a helpful reference in evaluating neuropathy, whether SEP or a conventional diagnostic study is employed. The conduction velocity of the median sensory nerve in 46 normal, healthy Korean individuals was determined, using SEP, and the findings compared with the findings of investigators in other countries. The mean conduction velocity was 63.15 +/- 5.00m/sec; the mean latency following stimulation at the wrist was 18.27 +/- 1.35 msec, and at the elbow 14.58 +/- 1.23 msec. Significant positive correlation of N20 latency with subject's height were found.
Adult ; Body Height ; Comparative Study ; Evoked Potentials, Somatosensory* ; Female ; Human ; Korea ; Male ; Median Nerve/physiology* ; Middle Age ; Neural Conduction*

OBJECTIVE: To provide the evidences for the choice of normal reference value of nerve conduction velocity (NCV) in clinical forensic appraisal. METHODS: One hundred and fourteen cases with normal peripheral nerve and 155 cases with injured peripheral nerve were collected. The NCV of homonymous nerves in two limbs were detected. In the normal cases, the NCV of the left limbs were used as the normal reference values. The NCV of the right limbs were compared with that of left limbs, the commendatory normal reference values from Beijing Xiehe Hospital and Shanghai Huashan Hospital. In the injured cases, the results of NCV in injuried limbs were compared with the results of healthy limbs and the reference values from Beijing Xiehe Hospital and Shanghai Huashan Hospital. RESULTS: In the normal group, there was no statistical difference between the left and right limbs in NCV results of homonymous nerve (P > 0.05). The false positive rates (FPR) were 0, 11.4% and 5.2% for three choices normal reference respectively. The false negative rates (FNR) were 0, 9.7% and 12.3% for three choices normal reference in injuried group. Thee false negative cases were all slight nerve injury. CONCLUSION The reference value of self-control method could decrease the FPR of normal cases and FNR of injured cases. In clinical forensic appraisal of peripheral nerve, the nerve condition study results from healthy homonymous nerve should be regarded as the reference value at first, supplemented by reference values from clinical labs.
Adolescent ; Adult ; Electrodiagnosis/methods* ; Forearm ; Forensic Medicine ; Humans ; Median Nerve/physiology* ; Middle Aged ; Neural Conduction/physiology* ; Peripheral Nerve Injuries/diagnosis* ; Peripheral Nerves/physiology* ; Reference Values ; Ulnar Nerve/physiology* ; Young Adult

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease involving both upper and lower motor neurons with no effective cure. Electrophysiological studies have found decremental responses during low-frequency repetitive nerve stimulation (RNS) except for diffused neurogenic activities. However, the difference between ALS and generalized myasthenia gravis (GMG) in terms of waveform features is unclear. In the current study, we explored the variation trend of the amplitudes curve between ALS and GMG with low-frequency, positive RNS, and the possible mechanism is discussed preliminarily. METHODS: A total of 85 ALS patients and 41 GMG patients were recruited. All patients were from Peking Union Medical College Hospital (PUMCH) between July 1, 2012 and February 28, 2015. RNS study included ulnar nerve, accessory nerve and facial nerve at 3 Hz and 5 Hz stimulation. The percentage reduction in the amplitude of the fourth or fifth wave from the first wave was calculated and compared with the normal values of our hospital. A 15% decrease in amplitude is defined as a decrease in amplitude. RESULTS: The decremental response at low-frequency RNS showed the abnormal rate of RNS decline was 54.1% (46/85) in the ALS group, and the results of different nerves were 54.1% (46/85) of the accessory nerve, 8.2% (7/85) of the ulnar nerve and 0% (0/85) of the facial nerve stimulation, respectively. In the GMG group, the abnormal rate of RNS decline was 100% (41/41) at low-frequency RNS of accessory nerves. However, there was a significant difference between the 2 groups in the amplitude after the sixth wave. CONCLUSIONS Both groups of patients are able to show a decreasing amplitude of low-frequency stimulation RNS, but the recovery trend after the sixth wave has significant variation. It implies the different pathogenesis of NMJ dysfunction of these 2 diseases.
Action Potentials ; physiology ; Adult ; Aged ; Amyotrophic Lateral Sclerosis ; physiopathology ; therapy ; Electric Stimulation Therapy ; Electromyography ; Female ; Humans ; Male ; Median Nerve ; physiology ; Middle Aged ; Motor Neurons ; physiology ; Muscle, Skeletal ; physiology ; Myasthenia Gravis ; physiopathology ; therapy ; Retrospective Studies ; Ulnar Nerve ; physiology

The objective of this study was to compare the MRI findings of wrists in patients diagnosed with CTS with those of the healthy controls, and to evaluate the correlation between the MRI differences and the electrophysiological findings in the patient group. This study involved 55 wrists, 30 of which were clinically and electrophysiologically diagnosed with CTS and 25 healthy controls. These 55 wrists were evaluated electrophysiologically, and in terms of median nerve diameter, ratio of median nerve diameter at psiform bone level to distal radio-ulnar joint level, the flexor retinaculum bulging ratio and the median nerve intensity by MRI. When the patient group, which were clinically and electrophysiologically diagnosed with CTS, and the healthy control group were compared, a significant difference (p < 0.001) was observed between the two in terms of median nerve diameters (at psiform bone level: 8.47 +/- 1.41mm and 2.91 +/- 1.01 mm, distal radio-ulnar joint level: 4.04 +/- 1.06 mm and 2.42 +/- 0.95 mm), ratio of median nerve diameter at psiform bone level to distal radio-ulnar joint level (2.17 +/- 0.54 and 1.25 +/- 0.12), their flexor retinaculum bulging ratios (26.21 +/- 5.98% and 7.27 +/- 4.53%) and their median nerve intensities. In the patient group, no significant correlation between MRI and the electrophysiological findings was found (p > 0.05). According to the data obtained from the study, we believe that the MRI examination of structural changes that occur in the carpal tunnel, neighboring structures and the median nerve would be useful in the diagnosis of CTS, especially in cases with suspected clinical and electrophysiological diagnosis.
Action Potentials ; Adult ; Carpal Tunnel Syndrome/*diagnosis/*physiopathology ; Electrophysiology ; Female ; Human ; *Magnetic Resonance Imaging ; Male ; Median Nerve/physiopathology ; Middle Aged ; Neurons, Afferent/physiology ; Reaction Time ; Reference Values

The superficial brachial artery (SBA), a branch of the axillary artery, is one of the most common arterial variations in this area. While it is more vulnerable to accidental arterial injection or injury, it could be useful for the nourishment of a medial arm skin free flap. To analyze the relationship between the SBA of axillary origin and segmental variation of the axillary artery, we dissected 304 arms of Korean cadavers. We found an SBA of axillary origin in 12.2% of cadaveric arms. Unilateral occurrence was detected in 16 cadavers and bilateral in 10. SBAs gave rise to radial and ulnar arteries in the cubital fossa (8.9%), continued in the forearm as the radial artery (2.3%), or ended in the upper arm (1.0%). The SBA ended as ulnar artery was not found in any of the cadavers. The bifurcation of the SBA into the radial and ulnar arteries, presence of an SBA that ends in the upper arm, and the lack of continuation as the ulnar artery are characteristics of SBAs in Korean cadavers.
Arm/*blood supply ; Axillary Artery/anatomy & histology ; Brachial Artery/*anatomy & histology/*physiology ; Cadaver ; Female ; Humans ; Korea ; Male ; Median Nerve/blood supply ; Models, Anatomic ; Radial Artery/anatomy & histology ; Ulnar Artery/anatomy & histology