Contralateral Electroacupuncture Relieves Chronic Neuropathic Pain in Rats with Spared Nerve Injury.

BACKGROUND Acupuncture and electroacupuncture (EA) are widely applied in the treatment of various conditions, including pain. Acupuncture stimulation is applied not only in areas close to pain sites, but also in distal regions or on the contralateral side of the body. Identifying which acupuncture paradigms produce best therapeutic effects is of clinical significance. MATERIAL AND METHODS Spared nerve injury (SNI) was applied to establish a rat model of neuropathic pain. We applied 14 sessions of EA (BL 60 and BL 40, 1-2 mA, and 2 Hz, 30 min per session) every other day from days 3 to 29 after surgery on the contralateral or ipsilateral side of pain. von Frey hair was applied to examine mechanical allodynia in the SNI model and analgesic effects of EA. All experimental procedures were approved by the Animal Care and Use Committee of our university, according to the guidelines of the International Association for the Study of Pain. RESULTS SNI produced significant and long-lasting mechanical allodynia (p<0.001) in injured paws. Repeated EA on the contralateral side of the pain significantly attenuated mechanical allodynia from 14 days after surgery (p<0.05). By contrast, ipsilateral EA did not show analgesic effects (p>0.05). CONCLUSIONS These findings indicate that contralateral EA is superior to local EA in some types of pain disorders. Further investigations are needed for a more comprehensive understanding of the central mechanisms of acupuncture.

[Effects of garlic oil on 2, 5-HD induced lipid peroxidation damage in rat nerve tissues].

OBJECTIVE: To investigate the effects of garlic oil (GO) against the peroxidation damage of rat nerve tissue and the peripheral motor neuropathy induced by 2, 5-HD. METHODS: Male Wistar rats were divided into four groups, with 10 in each group. The model group, and low and high doses of GO groups were administrated with 2, 5-HD (ip, 300 mg/kg), respectively; The control group was treated with sodium chloride, five times per week for six weeks. Pretreatment with GO gavaged (40 mg/kg or 80 mg/kg) started one week be-fore 2, 5-HD treatment, and lasted to the end of the experiment. Neurobehavioral indexes were examined at the zero, second and fourth week. At the end of the experiment, the scores of the gait, and the concentration of MDA and GSH, the level of TAOC and the ability of inhibition of.OH in cerebrum, spinal cord and sciatic nerve were examined. RESULTS: Compared with the zero week, except of the control group rats, the hind limb landing foot splay of three groups rats decreased by 44%, 50% and 49% at the fourth week, respectively without significant difference. The threshold value of balance in model, GO low and high doses groups rats decreased by 30%, 45% and 68% at the fourth week, respectively, and lower than the control group rats (P < 0.01). GO low and high doses groups rats showed the serious abnormality at the fourth week, before one week of the model group rats. The scores of gait of model, and GO low and high doses groups rats increased significantly compared with control group rats, and the GO high dose group rats were higher than model group rats (P < 0.05). Increase of the concentration of MDA, and decrease of the level of the ability of inhibition of.OH were induced by 2, 5-HD in cerebrum, spinal cord and sciatic nerve. The concentration of MDA increased, and the level of the ability of inhibition of.OH decreased (P < 0.05 or P < 0.01), respectively. The results showed that the concentration of MDA decreased, and the level of the ability of inhibition of.OH induced by GO in cerebrum, spinal cord and sciatic nerve increased, the concentration of MDA of GO low doses group rats decreased, the level of the ability of inhibition of.OH increased, the concentration of MDA of GO high doses group rats decreased (P < 0.01) respectively, and the level of the ability of inhibition of.OH increased (P < 0.01) in nerve tissue. CONCLUSION: GO has antagonist effect on the 2, 5-HD induced peroxidation damage, but can not improve the function of the peripheral motor nerve, indicating that the lipid peroxidation does not play an important role in 2, 5-HD neurotoxicity.

Computation of the electrical potential inside the nerve induced by an electrical stimulus.

The aim is to investigate the activation conditions of the different nerves which control the bladder. The selective stimulation of the nerve fibers depends on electrode configuration and intensity of applied current. The goal of this study is to compute the electrical potential inside the nerve due to an applied boundary currents. A symmetrically cylindrical model, representing the geometry and electrical conductivity of a nerve surrounded by a connective tissue and a cuff is used. In the quasistatic approximation, the problem can be modeled by a Poisson equation with Neumann boundary conditions. A symmetric boundary integral formulation is discretized using mixed finite elements. We can thus compute an electrical potential distribution depending on the electrode configuration and the applied current inside a nerve. Our results show that the distribution of the electrical potential inside a nerve or a fascicle depends on the geometry of the electrode and the shape of the applied current.

The transcutaneous charger for implanted nerve stimulation device.

Implanted nerve stimulation offers many advantages to improve the QOL (quality of life) of the patients suffering from nervous system diseases such as Parkinson's disease and epilepsy. Secondary battery begins to be used instead of primary secondary, service life of the implanted device is extended and the device becomes smaller and lighter. For charging the secondary battery fit in the body, a transcutaneous charger is designed. Two coupling coils designed specially are used to transmit and receive energy. With the mentioned coupling coils, the charger attains 15 mA charge current and the charge requirement is satisfied.

Discernment of adipose versus nervous tissue: a novel adjunct solution in lipomyelomeningocele surgery.

OBJECTIVE: To determine a solution capable of discerning adipose versus nervous tissue, to aid in surgical separation of the adipose tissue which appears to be visually indistinguishable from nervous tissue in lipomyelomeningoceles (LMMs). METHODS: The following solutes (in normal saline) were investigated, both at 25 and 37 degrees C: beta-carotene, vitamin D, vitamin E, lecithin, hydrogen peroxide, lipase, protease, hyaluronidase, partially purified collagenase, purified collagenase, trypsin, trypsin plus purified collagenase and non-solute-containing saline (control). Each solution was applied to a pediatric lipoma to determine gross effects over a period of approximately 30 min. If a solution appeared to affect the adipose tissue grossly, studies of functional in vivo sensory evoked and spontaneous potentials using that particular solution were conducted upon sheep spinal cord, nerve roots, dura and peripheral nerve. Additionally, histological studies were conducted to determine the effect of that solution upon adipose tissue, spinal cord, myelin, dura and nerve roots. RESULTS: Of all solutions investigated, partially purified collagenase type 1 (T1C; Lot M0M4322, Code CLS-1, Worthington Biochemical Corporation, Lakewood, N.J., USA) at 37 degrees C was the most successful in grossly altering the consistency and appearance of adipose tissue. This change was more apparent over 20-30 min following application of the solution to the adipose tissue. Solutions not containing T1C did not show appreciable results; purified collagenase plus trypsin did not appear comparable or superior to T1C. No significant histological or functional change was noted when comparing the spinal cord, nerve rootlets, myelin, dura or peripheral nerve from the T1C-treated group versus normal (untreated) control groups. CONCLUSION: T1C appears to be a potentially effective solution for application during LMM surgery in the acute setting, and such use of an adjunct solution may significantly aid in the safe surgical resection of LMMs. Pending further research, this technique may be applied for other indications which require discernment or alteration of adipose versus nervous tissue.

Transurethral microwave thermotherapy: how does it work?

Although some authors have proposed that the favorable impact of transurethral microwave thermotherapy (TUMT) for benign prostatic hyperplasia has only a placebo effect, this idea is inconsistent with the findings of a number of sham-controlled clinical trials. Histologic and immunohistochemical studies have shown that the nerve fibers in the periurethral tissue are damaged or ablated by TUMT, and it appears that the heat affects the innervation of the smooth muscle cells. Among the nerves damaged are the sensory neurons of the posterior urethra, and this change might reduce the excitatory signals from the urethrodetrusor facilitating reflexes. Necrosis and apoptosis within a limited area also have been described. Thus, there is likely more than one basis for the therapeutic effect of TUMT.

Acute and chronic implantation of coiled wire intraneural electrodes during cyclical electrical stimulation.

The posterior tibial nerves of 18 rabbits were intraneurally implanted with coiled wire electrodes for up to 9 weeks to evaluate their usefulness for neuromuscular electrical stimulation. In one group an electrode was implanted and removed in one leg while the other leg was chronically implanted. A second group was chronically implanted without electrical stimulation in one leg and implanted with cyclical electrical stimulation applied through the electrode in the other leg. No significant changes in nerve conduction velocities between the time of implantation and up to 9 weeks post-implantation were observed in either the stimulated or the non-stimulated nerves. Little change in motor current threshold was observed beyond 10 days post-implantation. The nerves showed little or no histologic demyelination or denervation in most specimens, although in about 40% of the nerves, a bulbous formation of connective tissue was observed at electrode entry and exit sites with some demyelination in these regions. The spinal cords showed no histologic abnormalities in either group. The gastrocnemius and soleus muscles showed only occasional signs of denervation. One cat was implanted in both the posterior tibial and peroneal nerves of each leg for a 4-year period. Threshold current showed very little change during the implantation period. The nerves showed minimal focal demyelination at the electrode site and the muscles showed normal fibers.