BACKGROUND: Different types of injury to the sciatic nerve branches produces different levels of each kind of nociception. In this study, we undertook to identify the nature of the partial sciatic nerve injury that affects nociceptive reaction to subcutaneous formalin injection, and to determine the branch of the sciatic nerve involved. METHODS: Sprague-Dawley rats were randomly divided into 4 groups, control group (n = 9) in which a sham operation was performed, a sural nerve transection group (n = 5), a tibial nerve transection group (n = 5), and a common peroneal nerve transection group (n = 5). Under enflurane anesthesia, sural, tibial, or common peroneal nerves were injured and responses to formalin test were compared for the four groups 24 hours after surgery. RESULTS: Pain behavior in the tibial and common peroneal nerve transected groups reduced in phase 2, but not in phase 1, while sural nerve transected group showed no change in response in either phase. CONCLUSIONS: Tibial and common peroneal nerves mainly affect phase 2 reaction in the formalin test in this partial sciatic nerve injury model.
Anesthesia ; Animals ; Control Groups ; Enflurane ; Formaldehyde* ; Models, Animal ; Nociception ; Pain Measurement* ; Peroneal Nerve ; Rats* ; Rats, Sprague-Dawley ; Sciatic Nerve* ; Sciatic Neuropathy ; Sural Nerve ; Tibial Nerve

OBJECTIVE: To determine if stretching the sciatic nerve in control and patients with lumbosacral radiculopathy significantly alters F-wave parameters. METHOD: We studied F-waves in the deep peroneal & posterior tibial nerves of 20 patients with unilateral lumbosacral radiculopathies and 22 controls. F-waves were recorded bilaterally in the neutral position and supine in 30o & 60o straight leg raising (SLR). F-wave parameters included minimal latency (F min), maximal latency (F max), mean latency (F mean), latency difference between F min and F max (chronodispersion), mean duration (F dur) and side to side difference in F min, F max, F mean and F dur. RESULTS: In controls, the F-wave latency was found to be longer in supine with SLR than in neutral position. In patients with lumbosacral radiculopathy, significant differences of F max, F mean and F dur between sides during 30o SLR were noted in the deep peroneal nerves, but all parameters in the posterior tibial nerves during SLR were not changed. CONCLUSION: In this study, we observed significant changes in F-wave latency in control during straight leg raising, but no significant changes in patients with lumbosacral radiculopathy. For the clinical application to lumbosacral radiculopathy, further study is needed.
Humans ; Leg* ; Peroneal Nerve ; Radiculopathy* ; Sciatic Nerve ; Tibial Nerve

OBJECTIVE: The authors evaluate the effects of each spinally administered MK-801, naloxone and coadministerd both drugs on the neuropathic pain states in the sympathetically independent pain(SIP) model induced by unilateral sural and tibial nerve transection of the sciatic nerve branches in the rat. METHODS: Pain sensitivity was measured with a von Frey filament for mechanical allodynia and acetone applied to the sensitive area for cold hyperalgesia. We evaluated the ability of the spinally applied MK-801 to spinal cord after laminectomy on T12, T13 and L1 to alleviate neuropathic pain either by itself of when spinally or intravenously administerd together with naloxone and coincidentally measured the behavioral test. RESULTS: Twenty out of 25 rats in which the tibial and sural nerves were injured showed well-developed neuropathic pain behaviors. The response rates of the rat models to the von Frey filament and acetone spray in hindlimbs by MK-801 were significantly reduced but, by naloxone were not changed. The pharmacological inhibition to mechanical allodynia and cold hyperalgesia for MK-801 when co-adminstered naloxone was reversed. CONCLUSION: MK-801 has been shown to alleviate neuropathic pain in SIP but, co-administered naloxone reversed the N-methyl-D-aspartate blocking effects of MK-801. These findings suggest that naloxone, which does not specifically relieve neuropathic pain, can reverse the neuropathic pain-relieving action of MK-801.
Acetone ; Animals ; Dizocilpine Maleate* ; Hindlimb ; Hyperalgesia ; Laminectomy ; Models, Animal* ; N-Methylaspartate ; Naloxone* ; Neuralgia* ; Rats* ; Sciatic Nerve ; Spinal Cord ; Sural Nerve ; Tibial Nerve

In 1999 Kayikcioglu and his colleagues invented the oblique nerve coaptation technique which increases coaptation surface and proved that their technique is superior to conventional vertical coaptation technique. This method is useful but it is not fit for a clinical application because the sciatic nerve was cut obliquely and repaired immediately in their experiment. In that case, we couldn't exclude the possibility of the improved effect by increased orientation of nerve fiber. Using different nerves we could exclude the effect by orientation improvement and prove the superiority of the oblique nerve coaptation technique in functional restoration. Ten Sprague-Dawley rats were used. The tibial nerve and the peroneal nerve were cut randomly to 30 degree and 90 degree on each side. The distal stump of the tibial nerve and the proximal stump of the peroneal nerve were repaired with 10-0 nylon under microscopic view. 12 weeks after nerve coaptation, nerve conduction velocity of extensor digitorum longus muscle, moist weight and histological analysis of extensor digitorum longus muscle, and myelinated axonal count and histological analysis of peroneal nerve were investigated. The results showed the nerves of oblique coaptation(30 degree transection angle) group are more regenerated than those of vertical coaptation(90 degree transection angle) group and nerve conduction velocity and moist weight of extensor digitorum longus muscle are also increased in oblique coaptation group. From these results we came to a conclusion that the oblique nerve coaptation technique is superior to the conventional technique and may be helpful in innervated free flap or nerve graft.
Axons ; Free Tissue Flaps ; Myelin Sheath ; Nerve Fibers ; Neural Conduction ; Nylons ; Peroneal Nerve ; Rats, Sprague-Dawley ; Sciatic Nerve ; Tibial Nerve ; Transplants

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

Six patients with twenty histologically proven neurilemmomas of the extremities were studied using magnetic resonance(MR) imaging. The size, number, signal intensity on spin-echo T1WI(TR 500-650ms/TE 14-25ms)and gradient -echo (TR 200-600ms/TE 14-20ms; flip angle 25-30)image, enhancement pattern, detectability of nerve of origin, nerve-lesion relationship, and presence of a capsule were analyzed. The masses ranged from 1 to 12cm in longitudinal diameter and originated from the median nerve, ulnar nerve, sciatic nerve, radial nerve, and tibial nerve. All the nerve tracts except for those of 5 lesions, which could not be detected due to their small diameter, were visualized as low intensity tubular structures. All visible nerve tracts were situated along the periphery of the lesion and this finding was considered to be specific for neurilemmona. All neurilemmomas were isointense with the surrounding muscle on spin-echo T1WI and hyperintense on gradient-echo image. After a GD-DTPA injection, all masses showed moderate or marked enhancement and more prominent inhomogeneity than that on nonenhanced scan. In 19 out of 20 lesions(95%), a low signal intensity capsule surrounding the masses could be seen. Four of the six patients showed multiple masses, which was unusual as neurilemmoma usually arises as a solitary mass. In conclusion, the MR findings, especially the eccentric location of the mass lesion from the nerve of origin and the presence of a capsule, were useful in making a diagnosis of neurilemmoma of the extremity and that multiple neurilemmomas were not uncommon.
Diagnosis ; Extremities* ; Gadolinium DTPA ; Humans ; Median Nerve ; Neurilemmoma* ; Radial Nerve ; Sciatic Nerve ; Tibial Nerve ; Ulnar Nerve

A schwannoma is one of the most common neoplasms in the central and peripheral nervous systems, but schwannomas of the sciatic nerve are rare. Treatment is a surgical excision and the overall prognosis is good. But functional loss occurs when a neurectomy is performed with inevitable cause. We report one case of a successful sural nerve graft after resection of a schwannoma in a sciatic nerve and we present a brief review of the literature.
Neurilemmoma* ; Peripheral Nervous System ; Prognosis ; Sciatic Nerve* ; Sural Nerve* ; Transplants

BACKGROUND: Various etiologies are the causative agents for sciatic neuropathy. We present here a case of ischemic sciatic neuropathy in a patient with liposarcoma. CASE REPORT: A 55-year-old woman presented with severe pain and weakness of the left leg. She had a history of recurred retroperitoneal liposarcoma, and was being administered chemotherapy. Examination revealed weakness in ankle dorsiflexion, plantar flexion and hamstring. Complaints also included dysesthesia, and numbness in the sole and dorsum of the foot. Nerve conduction study showed low compound muscle action potentials and slow motor conduction velocity of left peroneal and tibial nerves, with indiscernible sensory nerve action potentials of the left superficial peroneal and sural nerves. Computed tomography angiography revealed occlusion of the left common iliac artery. Commencement of intravenous infusion of heparin resulted in skin color change and progression of the weakness. Hence, the patient underwent an emergency thrombectomy. CONCLUSIONS: Ischemia should be considered as a cause of sciatic neuropathy in cancer patients, which requires management with timely treatment.
Action Potentials ; Angiography ; Ankle ; Drug Therapy ; Emergencies ; Female ; Foot ; Heparin ; Humans ; Hypesthesia ; Iliac Artery ; Infusions, Intravenous ; Ischemia ; Leg ; Liposarcoma ; Middle Aged ; Neural Conduction ; Paresthesia ; Sciatic Neuropathy ; Skin Pigmentation ; Sural Nerve ; Thrombectomy ; Tibial Nerve

OBJECTIVE: To identify the precise locations of the motor branches and motor points of hamstring and triceps surae muscles to the bony landmarks. METHOD: Twenty-eight limbs of 14 adult cadavers were anatomically dissected. The adult cadavers were selected randomly without regard to gender and age. The cadravers which were unable to obtain a neutral position or which received a trauma to the posterior thighs or the lower legs were excluded from the study. The number and location of the motor branches and motor points from sciatic nerve to each hamstirng muscles and from tibial nerve to each triceps surae muscles were identified related to the bony landmarks. Bony landmarks were ischial tuberosity, medial and lateral epicondyles of femur, and medial and lateral malleolli of tibia. The length of femur was defined as the distance from the ischial tuberosity to the intercondylar line of femur and the length of lower leg was defined as the distance from the intercondylar line of femur to the intermalleolar line of tibia. The locations of the muscular branches and the motor points were expressed as the percentage of the length of femur and lower leg. RESULTS: One muscular branch from the sciatic nerve to the semimembranosus muscle and from the posterior tibial nerve to the soleus muscle, and one or two muscular branches to the biceps femoris, semitendinosus, and semimembranosus, medial gastrocnemius, lateral gastrocnemius and soleus muscle were located at 23.0+/-5.7%, 21.0+/-10.5%, 25.0+/-10.3% of the femur from the ischial tuberosity and 2.0+/-6.2%, 4.0+/-3.3% and 10.0+/-3.3% of the lower leg from the intercondylar line of femur. There were one to four motor points in the hamstring and triceps surae muscles. The motor points of biceps femoris, semitendinosus and semimembranosus were located at 33.0+/-7.8%, 28.0+/-14.5% and 48.0+/-19.0% of the femur. The motor points of the medial gastrocnemius, lateral gastrocnemius and soleus were located in 5.0+/-0.6%, 10.0+/-3.0% and 18.0+/-4.3% of the lower leg below the intercondylar line of femur. CONCLUSION: The identification of the locations of muscular branches and motor points related to the bony landmarks from this study would increase the accuracy of the motor branch blocks or motor point blocks to the hamstrings and triceps surae muscles.
Adult ; Cadaver ; Extremities ; Femur ; Humans ; Leg ; Muscle, Skeletal ; Muscles* ; Sciatic Nerve ; Thigh ; Tibia ; Tibial Nerve