Allodynia is the sensation of pain due to non-painful stimuli. It usually occurs due to destructive lesions of the spinal cord or peripheral nerves. Allodynia following intradural lipoma surgery has been reported previously. We herein report a case of allodynia developed after microsurgical caudal lipoma excision without associated spinal cord injury.
Hyperalgesia ; Lipoma ; Peripheral Nerves ; Sensation ; Spinal Cord ; Spinal Cord Injuries

BACKGROUND: Glucocorticoids have anti-inflammatory effects and have been used to treat many types of nerve injury- associated chronic pain conditions. A randomized double-blind study was performed to determine if methylprednisolone could prevent the development of neuropathic pain after a peripheral nerve injury in rats. METHODS: Two groups of rats, one group (n = 50) injected intraperitoneally with methylprednisolone (100 mg/kg/day, for 7 days starting from 3 days prior to the nerve injury) and the other (n = 58) treated with saline with same manner, were compared in terms of the incidence and intensity of allodynia after a superior caudal trunk transection at the level between the 3rd and 4th sacral spinal nerves. The tail-flick responses to normally innocuous mechanical and thermal stimuli applied to the tail were observed as the behavioral signs of neuropathic pain. RESULTS: The proportions of rats exhibiting tail-flick responses to the mechanical (but not thermal) stimuli 7, 14 and 21 days after the nerve injury were significantly smaller in the methylprednisolone-treated group (2, 3 and 4 of 50 rats, respectively) than in the saline-treated, control group (11, 14 and 15 of 58 rats, respectively) (P = 0.009). However, the pain intensity was similar in mechanical allodynia developed rats of the two groups (P > 0.05), which was estimated based on the frequency and latency of the tail-flick responses after applying mechanical and thermal stimuli, respectively. CONCLUSIONS: These results suggest that a pre-emptive treatment with high methylprednisolone doses may be used to prevent the development of mechanical allodynia following peripheral nerve injuries.
Animals ; Axotomy ; Chronic Pain ; Double-Blind Method ; Glucocorticoids ; Hyperalgesia* ; Incidence ; Methylprednisolone* ; Neuralgia ; Peripheral Nerve Injuries* ; Peripheral Nerves* ; Rats* ; Spinal Nerves

Neurologic disorders from electrical injury may be classified as cerebral syndroms, spinal syndroms, peripheral nerve syndromes. Neurological complication involving either cerebral complication (loss of consciousness, seizures, decreased memory, headache) or peripheral complaints (sensorimotor loss, paraesthesias, paralysis, paresis, dysthesias) are described in the current literatures. However, the exact site of neurological damage causing paralysis after electrical trauma ramains to be clarified. Although transient tetraplegia has been previously reported following high-voltage electrical injury, the following case report describes an unusual presentation of transient acute tetraplegia following a low-voltage electrical injury.
Consciousness ; Memory ; Nervous System Diseases ; Paralysis ; Paresis ; Peripheral Nerves ; Quadriplegia* ; Seizures ; Shock* ; Spinal Cord Injuries

Cerebral somatosensory evoked potentials(SEPs) produced by stimulation of peripheral nerves provide a useful diagnostic index of conduction in somatosensory pathways to the cortex. Thus the integrity of both the dorsal column-medial lemniscus pathway and primary sensorimotor area has been considered an essential requirement to record a normal SEP. There are suggestions that SEPs contain several components arising from different neuronal sources, the early short latency potentials corresponding to the lemniscus-mediated responses and the late waves to the diffuse spino-thalamic projections. The present work analyses the influence on SEPs of focal brain lesions, using the computerized tomography in detecting and localizing brain lesions. Somatosensory evoked potentials were recorded in 20 patients with focal brain lesions recognized by computerized tomography. 1) Patients with primary sensorimotor area(PSMA) damages(group I) had a very abnormal of the early component(No, Po, Nl, Pl) in 100% on the lesion side. 2) Patients presented supratentorial lesions, sparing PSMA(group II), 87.5% showing abnormal SEPs in early components and characterized by increment of amplitude in late components. 3) Brainstem damage(group III) produced a distortion of the early components especially N11, N20msec in latency. 4) In incomplete spinal cord injuries, the SEPs is indeed signal of functional recovery, of posterior column, and incorrespondance with clinical improvement.
Brain Stem ; Brain* ; Evoked Potentials, Somatosensory* ; Humans ; Neurons ; Peripheral Nerves ; Spinal Cord Injuries

Damage to peripheral nerves or the spinal cord is often accompanied by neuropathic pain, which is a complex, chronic pain state. Increasing evidence indicates that alterations in the expression and activity of gap junction channels in the spinal cord are involved in the development of neuropathic pain. Thus, this review briefly summarizes evidence that regulation of the expression, coupling, and activity of spinal gap junction channels modulates pain signals in neuropathic pain states induced by peripheral nerve or spinal cord injury. We particularly focus on connexin 43 and pannexin 1 because their regulation vastly attenuates symptoms of neuropathic pain. We hope that the study of gap junction channels eventually leads to the development of a suitable treatment tool for patients with neuropathic pain.
Chronic Pain ; Connexin 43 ; Gap Junctions* ; Hope ; Humans ; Neuralgia* ; Neuroglia ; Peripheral Nerves ; Spinal Cord ; Spinal Cord Injuries

PURPOSE: To determine the relationship between change in the expression of the p75 neurotrophin receptor (NTR) and transient receptor potential vanilloid 1 (TRPV1) after a spinal nerve injury with time. MATERIALS AND METHODS: The L5 and L6 spinal nerve of the rats were cut unilaterally. The spinal cord and dorsal root ganglion (DRG) were subjected to immunohistochemistry for p75 NTR and TRPV1. RESULTS: The immunoreaction (IR) for p75 NTR in the neuronal cytoplasm was persistently lower on the ipsilateral L5 and L6 DRG but higher in the satellite cells and fibers. The colocalization between p75 NTR and TRPV1 was increased temporarily in the L4 DRG in both sides. In the spinal cord, p75 NTR-IR decreased temporalily in the ipsilateral dorsal horn of the L4-L6 level and had recovered at 28 days after injury. CONCLUSION: These results show that a differential change in the expression of p75 NTR and TRPV1 is related to the different functional recovery of the sensory and motor system, and that increased colocalizations between p75 NTR and TRPV1 in a non-injured DRG might be related to the development of neuropathic pain after a peripheral nerve injury.
Animals ; Cytoplasm ; Diagnosis-Related Groups ; Ganglia, Spinal* ; Horns ; Immunohistochemistry ; Neuralgia ; Neurons ; Peripheral Nerve Injuries ; Rats* ; Receptor, Nerve Growth Factor* ; Spinal Cord* ; Spinal Nerve Roots* ; Spinal Nerves*

Peripheral nerve injury sometimes leads to neuropathic pain and depletion of calcitonin gene related-peptide (CGRP) and substance P (SP) in the spinal cord. However, the pathophysiological mechanisms for depletion of CGRP and SP following the neuropathic injury are still unknown. This study was performed to see whether the distribution of immunoreactivity for CGRP and SP in the superficial dorsal horn and dorsal root ganglia (DRG) was related to the distance between the DRG and injury site. To this aim, we compared two groups of rats; one group was subjected to unilateral inferior and superior caudal trunk transections at the level between the S3 and S4 spinal nerves (S34 group) and the other group at the levels between the S1 and S2, between S2 and S3 and between S3 and S4 spinal nerve (S123 group). The transections in both groups equally eliminated the inputs from the tail to the S1-3 DRG, but the distance from the S1/S2 DRG to the injury site was different between the two groups. Immunostaining with SP and CGRP antibody was done in the S1-S3 spinal cord and DRG of the two groups 1 and 12 weeks after the injury. The results obtained are as follows: 1. The immunoreactivity for CGRP and SP in the ipsilateral superficial dorsal horn and DRG decreased 1 and 12 weeks after neuropathic nerve injury. 2. The immunoreactive area of SP and CGRP in the S1 dorsal horn was smaller in the S123 group than in the S34 group, whereas that in the S3 dorsal horn was not significantly different between the two groups. The number of SP- immunoreactive DRG cells decreased on the neuropathic side as compared to the sham group's in all DRGs of experimental groups except the S1 DRG of the S34 group. These results suggest that the amounts of SP and CGRP in the dorsal horn and DRG following neuropathic injury inversely decrease according to the distance between the DRG and injury site.
Animals ; Calcitonin ; Diagnosis-Related Groups* ; Ganglia, Spinal ; Horns ; Hyperalgesia ; Neuralgia ; Peripheral Nerve Injuries ; Rats* ; Spinal Cord* ; Spinal Nerves ; Substance P ; Tail

The aim of this study was to propose new more reliable peripheral nerve transection model to overcome the defect of the traditional sciatic axotomy model by specifically transecting L5 spinal nerve just after emerging from the intervertebral foramen and confining analysis area to the L5 spinal segment. The adult male Sprague-Dawley rats, weighing 300~350 g at the time of surgery, were used for the experiments. Four different experimental groups were used. 1. Sciatic nerve transection (Sc-Tx) group: transect the sciatic nerve in the popliteal fossa where it divided into the common peroneal nerve and tibial nerve. 2. L5 spinal nerve transection (L5-Tx) group: L5 spinal nerve was specifically transected. 3. Suture (Su) group: L5 spinal nerve was transected and immediately sutured. 4. Control group: the same surgical procedure with L5 spinal nerve transection group was performed except for the excision of L5 spinal nerve. To distinguish L5 motoneurons from the other level ones, the animals were received the retrograde tracer, FluoroGold into the axotomized proximal nerve stump. Serial coronal frozen sections at 40 microm thick through the L4 to L6 spinal segment was performed and the resultant total number of sections was about 180. Approximate serial 50 sections (approximately 2 mm) could be considered as the L5 segment based on the number of the fluorescent signals (above 20). L5 spinal segment could be differentiated from L4 and L6 segment based on their morphological characteristics under Cresyl violet stain. In L5-Tx group, at 2 and 4 weeks post-transection, the number of L5 spinal motoneurons was reduced by 8%. Meanwhile, Sc-Tx and Su groups showed no statistically notable changes. In this study, the authors could propose more reliable peripheral nerve axotomy model than the conventional sciatic nerve axotomy model by specifically transecting L5 spinal nerve and confining the investigating area within the L5 spinal segment.
Adult ; Animals ; Axotomy ; Benzoxazines ; Frozen Sections ; Humans ; Male ; Peripheral Nerve Injuries ; Peripheral Nerves ; Peroneal Nerve ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; Spinal Nerves ; Sutures ; Tibial Nerve ; Viola

The aim of this study was to propose new more reliable peripheral nerve transection model to overcome the defect of the traditional sciatic axotomy model by specifically transecting L5 spinal nerve just after emerging from the intervertebral foramen and confining analysis area to the L5 spinal segment. The adult male Sprague-Dawley rats, weighing 300~350 g at the time of surgery, were used for the experiments. Four different experimental groups were used. 1. Sciatic nerve transection (Sc-Tx) group: transect the sciatic nerve in the popliteal fossa where it divided into the common peroneal nerve and tibial nerve. 2. L5 spinal nerve transection (L5-Tx) group: L5 spinal nerve was specifically transected. 3. Suture (Su) group: L5 spinal nerve was transected and immediately sutured. 4. Control group: the same surgical procedure with L5 spinal nerve transection group was performed except for the excision of L5 spinal nerve. To distinguish L5 motoneurons from the other level ones, the animals were received the retrograde tracer, FluoroGold into the axotomized proximal nerve stump. Serial coronal frozen sections at 40 microm thick through the L4 to L6 spinal segment was performed and the resultant total number of sections was about 180. Approximate serial 50 sections (approximately 2 mm) could be considered as the L5 segment based on the number of the fluorescent signals (above 20). L5 spinal segment could be differentiated from L4 and L6 segment based on their morphological characteristics under Cresyl violet stain. In L5-Tx group, at 2 and 4 weeks post-transection, the number of L5 spinal motoneurons was reduced by 8%. Meanwhile, Sc-Tx and Su groups showed no statistically notable changes. In this study, the authors could propose more reliable peripheral nerve axotomy model than the conventional sciatic nerve axotomy model by specifically transecting L5 spinal nerve and confining the investigating area within the L5 spinal segment.
Adult ; Animals ; Axotomy ; Benzoxazines ; Frozen Sections ; Humans ; Male ; Peripheral Nerve Injuries ; Peripheral Nerves ; Peroneal Nerve ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; Spinal Nerves ; Sutures ; Tibial Nerve ; Viola

Historically, peripheral neuropathic pain has occasionally been difficult to treat. Both a systematic review of the evidence as well as clinical experience have demonstrated that treatment options including polypharmacy provide effective pain relief in only half of the patients with neuropathic pain. After peripheral nerve injury, the incidence of degenerative alterations in the spinal cord and central pathologic sensitization are possible. Due to this observation, It may be difficult to treat this group of patients with peripheral neuropathic pain by therapeutic intervention of the peripheral nerve. Pulsed radiofrequency (PRF) has several benefits for treatment of this condition including, accuracy and safety, and the elimination of thermal lesions due to the reduction in the target tissue temperature (below 42 degrees). We treated three cases of supraorbital neuropathic pain using PRF, and discovered that two of the patients had significant pain relief at the six month time point.
Central Nervous System Sensitization ; Humans ; Incidence ; Neuralgia ; Peripheral Nerve Injuries ; Peripheral Nerves ; Peripheral Nervous System Diseases ; Polypharmacy ; Spinal Cord