Amongst the important phenomena in neurophysiology, nerve pulse generation and propagation is fundamental. Scientists have studied this phenomena using mathematical models based on experimental observations on the phy...Amongst the important phenomena in neurophysiology, nerve pulse generation and propagation is fundamental. Scientists have studied this phenomena using mathematical models based on experimental observations on the physiological processes in the nerve cell. Widely used models include: the Hodgkin-Huxley (H-H) model, which is based entirely on the electrical activity of the nerve cell;and the Heimburg and Jackson (H-J), model based on the thermodynamic activity of the nerve cell. These classes of models do not, individually, give a complete picture of the processes that lead to nerve pulse generation and propagation. Recently, a hybrid model proposed by Mengnjo, Dikandé and Ngwa (M-D-N), takes into consideration both the electrical and thermodynamic activities of the nerve cell. In their work, the first three bound states of the model are analytically computed and they showed great resemblance to some of the experimentally observed pulse profiles. With these bound states, the M-D-N model reduces to an initial value problem of a linear parabolic partial differential equation with variable coefficients. In this work we consider the resulting initial value problem and, using the theory of function spaces, propose and prove conditions under which such equations will admit unique solutions. We then verify that the resulting initial value problem from the M-D-N model satisfies these conditions and so has a unique solution. Given that the derived initial value problem is complex and there are no known analytic techniques that can be deployed to obtain its solution, we designed a numerical experiment to estimate the solutions. The simulations revealed that the unique solution is a stable pulse that propagates in the x-t plane with constant velocity and maintains the shape of the initial profile.展开更多
Most studies on peripheral nerve injury have focused on repair at the site of injury, but very few have examined the effects of repair strategies on the more proximal neuronal cell bodies. In this study, an approximat...Most studies on peripheral nerve injury have focused on repair at the site of injury, but very few have examined the effects of repair strategies on the more proximal neuronal cell bodies. In this study, an approximately 10-mm-long nerve segment from the ischial tuberosity in the rat was transected and its proximal and distal ends were inverted and sutured. The spinal cord was subjected to pulsed electrical stimulation at T10 and L3, at a current of 6.5 m A and a stimulation frequency of 15 Hz, 15 minutes per session, twice a day for 56 days. After pulsed electrical stimulation, the number of neurons in the dorsal root ganglion and anterior horn was increased in rats with sciatic nerve injury. The number of myelinated nerve fibers was increased in the sciatic nerve. The ultrastructure of neurons in the dorsal root ganglion and spinal cord was noticeably improved. Conduction velocity of the sciatic nerve was also increased. These results show that pulsed electrical stimulation protects sensory neurons in the dorsal root ganglia as well as motor neurons in the anterior horn of the spinal cord after peripheral nerve injury, and that it promotes the regeneration of peripheral nerve fibers.展开更多
BACKGROUND： The postoperative recovery of nerve function in patients with peripheral nerve injury is always an important problem to solve after treatment. The electric stimulation induced electromagnetic field can no...BACKGROUND： The postoperative recovery of nerve function in patients with peripheral nerve injury is always an important problem to solve after treatment. The electric stimulation induced electromagnetic field can nourish nerve, postpone muscular atrophy, and help the postoperative neuromuscular function. OBJECTIVE： To observe the effects of low-frequency pulse percutaneous electric stimulation on the functional recovery of postoperative patients with peripheral nerve injury, and quantitatively evaluate the results of electromyogram （EMG） examination before and after treatment. DESIGN ： A retrospective case analysis SETTING： The Sixth People＇s Hospital affiliated to Shanghai Jiaotong University PARTICIPANTS： Nineteen postoperative inpatients with peripheral nerve injury were selected from the De- partment of Orthopaedics, the Sixth People＇s Hospital affiliated to Shanghai Jiaotong University from June 2005 to January 2006, including 13 males and 6 females aged 24-62 years with an average of 36 years old. There were 3 cases of brachial plexus nerve injury, 3 of median nerve injury, 7 of radial nerve injury, 3 of ul- nar nerve injury and 3 of common peroneal nerve injury, and all the patients received probing nerve fiber restoration. Their main preoperative manifestations were dennervation, pain in limbs, motor and sensory disturbances. All the 19 patients were informed with the therapeutic program and items for evaluation. METHODS： ① Low-frequency pulse percutaneous electric stimulation apparatus： The patients were given electric stimulation with the TERESA cantata instrument （TERESA-0, Shanghai Teresa Health Technology, Co., Ltd.）. The patients were stimulated with symmetric square waves of 1-111 Hz, and the intensity was 1.2-5.0 mA, and it was gradually adjusted according to the recovered conditions of neural regeneration following the principle that the intensity was strong enough and the patients felt no obvious upset. They were treated for 4- 24 weeks, 10-30 minutes for each time, 1-3 times a day, and 6 weeks as a course. ② EMG examination was applied to evaluate the recoveries of recruitment, motor conduction velocity （MCV） and sensory conduction velocity （SCV） before and after treatment. The patients were examined with the EMG apparatus （DIS- A2000C, Danmark） before and after the treatment of percutaneous electric stimulation. ③Standards for evaluating the effects included cured （complete recovery of motor functions, muscle strength of grade 5, no abnormality in EMG examination）, obviously effective [general recovery of motor function, muscle strength of grade 4, no or a few denervation potentials, motor conduction velocity （MCV） and sensory conduction velocity （SCV）], improved （partial recovery of motor function, muscle strength of grade 3, denervation potentials and reinneration potentials, slowed MCV and SCV, invalid （no obvious changes of motor function）. MAIN OUTCOME MEASURES： ① Ameliorated degree of the nerve function of the postoperative patients with peripheral nerve injury treated with percutaneous electric stimulation; ② Changes of EMG examination before and after treatment. RESULTS： All the 19 postoperative patients with peripheral nerve injury were involved in the analysis of results. ① Comparison of nerve function before and after treatment in 19 patients with peripheral nerve injury of different sites： For the patients with radial nerve injury （n=7）, the nerve functions all completely recovered after 8-week treatment, and the cured and obvious rate was 100% （7/7）; For the patients with brachial plexus nerve injury （n=3）, 1 case had no obvious improvement, and the cured and obvious rate was 67% （2/3）; For the patients with common peroneal nerve injury （n=3）, the extension of foot dorsum generally recovered in 1 case of nerve contusion after 4-week treatment, and the cured and obvious rate was 67% （2/3）; For the patients with median nerve injury （n=3）, muscle strength was obviously recovered, and the cured and obvious rate was 100% （3/3）; For the patients with ulnar nerve injury （n=3）, 1 case only had recovery of partial senses, and the cured and obvious rate was 67% （2/3）. Totally 9 cases were cured, 7 were obviously effective, 1 was improved, and only 2 were invalid. After 4 courses, the cured rate of damaged nerve function after four courses was 47% （9/19）, and effective rate was 89% （17/19）.② Comparison of EMG examination before and after treatment： Before and after percutaneous electric stimulation, he effective rates of recruitment, MCV and SCV were 89% （17/19）, 58% （11/19）, 47% （9/19） respectively, and there were extremely obvious differences （P〈 0.01）. CONCLUSION： ①Low-frequency pulse percutaneous electric stimulation can improve the nerve function of postoperative patients with peripheral nerve injury of different sites, especially that the injuries of radial nerve and median nerve recover more obviously. ②Percutaneous electric stimulation can ameliorate the indexes of EMG examination, especially the recruitment, in postoperative patients with peripheral nerve injury.展开更多
文摘Amongst the important phenomena in neurophysiology, nerve pulse generation and propagation is fundamental. Scientists have studied this phenomena using mathematical models based on experimental observations on the physiological processes in the nerve cell. Widely used models include: the Hodgkin-Huxley (H-H) model, which is based entirely on the electrical activity of the nerve cell;and the Heimburg and Jackson (H-J), model based on the thermodynamic activity of the nerve cell. These classes of models do not, individually, give a complete picture of the processes that lead to nerve pulse generation and propagation. Recently, a hybrid model proposed by Mengnjo, Dikandé and Ngwa (M-D-N), takes into consideration both the electrical and thermodynamic activities of the nerve cell. In their work, the first three bound states of the model are analytically computed and they showed great resemblance to some of the experimentally observed pulse profiles. With these bound states, the M-D-N model reduces to an initial value problem of a linear parabolic partial differential equation with variable coefficients. In this work we consider the resulting initial value problem and, using the theory of function spaces, propose and prove conditions under which such equations will admit unique solutions. We then verify that the resulting initial value problem from the M-D-N model satisfies these conditions and so has a unique solution. Given that the derived initial value problem is complex and there are no known analytic techniques that can be deployed to obtain its solution, we designed a numerical experiment to estimate the solutions. The simulations revealed that the unique solution is a stable pulse that propagates in the x-t plane with constant velocity and maintains the shape of the initial profile.
基金supported by the Key Scientific and Technological Program of Linyi City of China,No.201313026
文摘Most studies on peripheral nerve injury have focused on repair at the site of injury, but very few have examined the effects of repair strategies on the more proximal neuronal cell bodies. In this study, an approximately 10-mm-long nerve segment from the ischial tuberosity in the rat was transected and its proximal and distal ends were inverted and sutured. The spinal cord was subjected to pulsed electrical stimulation at T10 and L3, at a current of 6.5 m A and a stimulation frequency of 15 Hz, 15 minutes per session, twice a day for 56 days. After pulsed electrical stimulation, the number of neurons in the dorsal root ganglion and anterior horn was increased in rats with sciatic nerve injury. The number of myelinated nerve fibers was increased in the sciatic nerve. The ultrastructure of neurons in the dorsal root ganglion and spinal cord was noticeably improved. Conduction velocity of the sciatic nerve was also increased. These results show that pulsed electrical stimulation protects sensory neurons in the dorsal root ganglia as well as motor neurons in the anterior horn of the spinal cord after peripheral nerve injury, and that it promotes the regeneration of peripheral nerve fibers.
基金grants from Sci-entific Research Fund of theMinistry of Health, No.20040801 Shanghai Ris-ing-Star Program of Technologi-cal Committee, No.05QMX1438
文摘BACKGROUND： The postoperative recovery of nerve function in patients with peripheral nerve injury is always an important problem to solve after treatment. The electric stimulation induced electromagnetic field can nourish nerve, postpone muscular atrophy, and help the postoperative neuromuscular function. OBJECTIVE： To observe the effects of low-frequency pulse percutaneous electric stimulation on the functional recovery of postoperative patients with peripheral nerve injury, and quantitatively evaluate the results of electromyogram （EMG） examination before and after treatment. DESIGN ： A retrospective case analysis SETTING： The Sixth People＇s Hospital affiliated to Shanghai Jiaotong University PARTICIPANTS： Nineteen postoperative inpatients with peripheral nerve injury were selected from the De- partment of Orthopaedics, the Sixth People＇s Hospital affiliated to Shanghai Jiaotong University from June 2005 to January 2006, including 13 males and 6 females aged 24-62 years with an average of 36 years old. There were 3 cases of brachial plexus nerve injury, 3 of median nerve injury, 7 of radial nerve injury, 3 of ul- nar nerve injury and 3 of common peroneal nerve injury, and all the patients received probing nerve fiber restoration. Their main preoperative manifestations were dennervation, pain in limbs, motor and sensory disturbances. All the 19 patients were informed with the therapeutic program and items for evaluation. METHODS： ① Low-frequency pulse percutaneous electric stimulation apparatus： The patients were given electric stimulation with the TERESA cantata instrument （TERESA-0, Shanghai Teresa Health Technology, Co., Ltd.）. The patients were stimulated with symmetric square waves of 1-111 Hz, and the intensity was 1.2-5.0 mA, and it was gradually adjusted according to the recovered conditions of neural regeneration following the principle that the intensity was strong enough and the patients felt no obvious upset. They were treated for 4- 24 weeks, 10-30 minutes for each time, 1-3 times a day, and 6 weeks as a course. ② EMG examination was applied to evaluate the recoveries of recruitment, motor conduction velocity （MCV） and sensory conduction velocity （SCV） before and after treatment. The patients were examined with the EMG apparatus （DIS- A2000C, Danmark） before and after the treatment of percutaneous electric stimulation. ③Standards for evaluating the effects included cured （complete recovery of motor functions, muscle strength of grade 5, no abnormality in EMG examination）, obviously effective [general recovery of motor function, muscle strength of grade 4, no or a few denervation potentials, motor conduction velocity （MCV） and sensory conduction velocity （SCV）], improved （partial recovery of motor function, muscle strength of grade 3, denervation potentials and reinneration potentials, slowed MCV and SCV, invalid （no obvious changes of motor function）. MAIN OUTCOME MEASURES： ① Ameliorated degree of the nerve function of the postoperative patients with peripheral nerve injury treated with percutaneous electric stimulation; ② Changes of EMG examination before and after treatment. RESULTS： All the 19 postoperative patients with peripheral nerve injury were involved in the analysis of results. ① Comparison of nerve function before and after treatment in 19 patients with peripheral nerve injury of different sites： For the patients with radial nerve injury （n=7）, the nerve functions all completely recovered after 8-week treatment, and the cured and obvious rate was 100% （7/7）; For the patients with brachial plexus nerve injury （n=3）, 1 case had no obvious improvement, and the cured and obvious rate was 67% （2/3）; For the patients with common peroneal nerve injury （n=3）, the extension of foot dorsum generally recovered in 1 case of nerve contusion after 4-week treatment, and the cured and obvious rate was 67% （2/3）; For the patients with median nerve injury （n=3）, muscle strength was obviously recovered, and the cured and obvious rate was 100% （3/3）; For the patients with ulnar nerve injury （n=3）, 1 case only had recovery of partial senses, and the cured and obvious rate was 67% （2/3）. Totally 9 cases were cured, 7 were obviously effective, 1 was improved, and only 2 were invalid. After 4 courses, the cured rate of damaged nerve function after four courses was 47% （9/19）, and effective rate was 89% （17/19）.② Comparison of EMG examination before and after treatment： Before and after percutaneous electric stimulation, he effective rates of recruitment, MCV and SCV were 89% （17/19）, 58% （11/19）, 47% （9/19） respectively, and there were extremely obvious differences （P〈 0.01）. CONCLUSION： ①Low-frequency pulse percutaneous electric stimulation can improve the nerve function of postoperative patients with peripheral nerve injury of different sites, especially that the injuries of radial nerve and median nerve recover more obviously. ②Percutaneous electric stimulation can ameliorate the indexes of EMG examination, especially the recruitment, in postoperative patients with peripheral nerve injury.
