Changes in nerve microcirculation following peripheral nerve compression

Following peripheral nerve compression, peripheral nerve microcirculation plays important roles in regulating the nerve microenvironment and neurotrophic substances, supplying blood and oxygen and maintaining neural conduction and axonal transport. This paper has retrospectively analyzed the articles published in the past 10 years that addressed the relationship between peripheral nerve compression and changes in intraneural microcirculation. In addition, we describe changes in different peripheral nerves, with the aim of providing help for further studies in peripheral nerve microcirculation and understanding its protective mechanism, and exploring new clinical methods for treating peripheral nerve compression from the perspective of neural microcirculation.

Brain remodeling after chronic median nerve compression in a rat model

Carpal tunnel syndrome is the most common compressive neuropathy,presenting with sensorimotor dysfunction.In carpal tunnel syndrome patients,irregular afferent signals on functional magnetic resonance imaging are associated with changes in neural plasticity during peripheral nerve injury.However,it is difficult to obtain multi-point neuroimaging data of the brain in the clinic.In the present study,a rat model of median nerve compression was established by median nerve ligation,i.e.,carpal tunnel syndrome model.Sensory cortex remodeling was determined by functional magnetic resonance imaging between normal rats and carpal tunnel syndrome models at 2 weeks and 2 months after operation.Stimulation of bilateral paws by electricity for 30 seconds,alternating with 30 seconds of rest period（repeatedly 3 times）,resulted in activation of the contralateral sensorimotor cortex in normal rats.When carpal tunnel syndrome rats received this stimulation,the contralateral cerebral hemisphere was markedly activated at 2 weeks after operation,including the primary motor cortex,cerebellum,and thalamus.Moreover,this activation was not visible at 2 months after operation.These findings suggest that significant remodeling of the cerebral cortex appears at 2 weeks and 2 months after median nerve compression.

A novel chronic nerve compression model in the rat

Current animal models of chronic peripheral nerve compression are mainly silicone tube models. However, the cross section of the rat sciatic nerve is not a perfect circle, and there are differences in the diameter of the sciatic nerve due to individual differences. The use of a silicone tube with a uniform internal diameter may not provide a reliable and consistent model. We have established a chronic sciatic nerve compression model that can induce demyelination of the sciatic nerve and lead to atrophy of skeletal muscle. In 3-week-old pups and adult rats, the sciatic nerve of the right hind limb was exposed, and a piece of surgical latex glove was gently placed under the nerve. N-butyl-cyanoacrylate was then placed over the nerve, and after it had set, another piece of glove latex was placed on top of the target area and allowed to adhere to the first piece to form a sandwich-like complex. Thus, a chronic sciatic nerve compression model was produced. Control pups with latex or N-butyl-cyanoacrylate were also prepared. Functional changes to nerves were assessed using the hot plate test and electromyography. Immunofluorescence and electron microscopy analyses of the nerves were performed to quantify the degree of neuropathological change. Masson staining was conducted to assess the degree of fibrosis in the gastrocnemius and intrinsic paw muscles. The pup group rats subjected to nerve compression displayed thermal hypoesthesia and a gradual decrease in nerve conduction velocity at 2 weeks after surgery. Neuropathological studies demonstrated that the model caused nerve demyelination and axonal irregularities and triggered collagen deposition in the epineurium and perineurium of the affected nerve at 8 weeks after surgery. The degree of fibrosis in the gastrocnemius and intrinsic paw muscles was significantly increased at 20 weeks after surgery. In conclusion, our novel model can reproduce the functional and histological changes of chronic nerve compression injury that occurs in humans and it will be a useful new tool for investigating the mechanisms underlying chronic nerve compression.

Optic nerve compression:the role of the lamina cribrosa and translaminar pressure

AIM： To describe the morphological changes of the lamina cribrosa （LC） in patients with optic nerve compression. METHODS： Cross-sectional study. Twenty eyes with optic nerve compression, affected by Graves＇ ophthalmopathy （GO） were compared with 18 refractive error-matched healthy eyes. The following examinations were performed： best-corrected visual acuity （BCVA）, intraocular pressure, optic nerve echography, visual field, SD-OCT including the retinal nerve fiber layer （RNFL）, ganglion cell complex （GCC）, and LC thickness and extent. RESULTS： A-scan revealed significant differences in the subarachnoid space （SAS） between the affected and control groups. LC thickness and LC area were 233 pm （SD 23） and 0.41 mm2 （SD 0.19）, respectively. Average GCC thickness （P=-0.0005）, LC thickness （P=-0.001）, MD （P=-0.001） and PSD （P=-0.001） differed significantly between the two groups; whereas LC area （P=-0.2） and average RFNL （P=-0.1） did not. CONCLUSION： Optic nerve compression reduces the SAS thereby altering the morphology of LC thickness and causing GCC damage.

Differential diagnosis of cervical nerve compression syndrome of the external intervertebral foramen

The aim of the present research is to study the mechanism of cervical nerve compression syndrome of the external intervertebral foramen and its differential diagnosis with cervical spondylosis.Diagnostic treatment with muscle relaxant,vasodilator,neurotrophic medicine and celecoxib(COX)-2 inhibitor were performed in 20 patients with cervical nerve compression syndrome of the external intervertebral foramen and 20 patients with cervical spondylosis confirmed by operation.Diagnostic local block therapy was performed additionally in cases showing little effect after diagnostic treatment.All the patients were followed up postoperatively for more than one year.Fifteen cases with cervical nerve compression syndrome of the external intervertebral foramen were healed by the diagnostic treatment.The other five cases had a short-term remission and there was no recurrence after diagnostic local block therapy.Diagnostic treatment led to short-term alleviation of the symptom in 20 cases with cervical spondylosis confirmed by operation,the results of which was far from satisfactory and operation was undertaken finally in all the 20 cases.The etiology of cervical nerve compression syndrome of the external intervertebral foramen lies in the compression of the cervical plexus,brachial plexus and cervical dorsal rami by the tendinous decussating fibers of the scalenus anticus,medius,minimus and the posterior muscles of the neck.Diagnostic treatment was propitious to differentiate cervical nerve compression syndrome of the external intervertebral foramen from cervical spondylosis.

Hereditary Multiple Exostoses (HME) with Peroneal Nerve Compresion: A Case Report

Introduction: Hereditary multiple exostosis (HME) is a hereditary disorder characterized by multiple osteochondromas. Clinical symptoms can result from compression of adjacent structures such as peripheral nerves. In Indonesia, HME with nerve compression cases have rarely reported. Presentation of Case: An eleven-year-old female with complaining of left knee joint pain and progressive masses in left lower leg since 6 years ago. This complains followed by numbness and difficulty to dorso flexion motion on left ankle joint since four months ago. Physical examination showed of the bony masses was detected at the left lateral upper third lower leg with measuring about six into eight centimeters. Range of motion of left ankle joint patient had difficult to dorso flexion. X-ray imaging viewed demonstrates multiple exostosis appearance involving distal femoral, proximal fibula, proximal tibia and distal fibula bone. MR Imaging revealed cartilage cap of head fibula is thin less 1.5 cm and the axially specimen showed peroneal nerve compression. The patient underwent left head fibula wide resection. Intraoperative findings peripheral nerve peroneal compression and was decompression. Medical rehabilitation for physiotherapy was advised. The results of the follow-up after 2 years, no pain feels and the patient was able to dorso flexion of left ankle joint and no additional bumps in other areas of the body. These lesions may arise from any bone which was pre-formed in the cartilage. Nerve compression syndromes are the neurological complex symptom caused by the mechanical or dynamic compression of a specific single segment. MRI was excellent demonstration of blood vessels compromise and represents choices with peripheral nerves structures and to measuring cartilage cap thickness for criterion of osteochondromas differentiation and exostotic grade. Complete resection was importance of the cartilaginous cap to prevent recurrence. The decompressing the peroneal nerve that pressured by the masses and vascular problems occured. Conclusion: Hereditary multiple exostosis is an inherited disorder characterized by multiple osteochondromas. It is important to monitor all cases of HME especially if the patient complains of pain or growth of an osteochondroma. The surgical excision, with complete resection of the cartilaginous cap of the tumor, is important in preventing recurrence.

Acupuncture at the “Huatuojiaji” point affects nerve root regional interleukin-1 level in a rat model of lumbar nerve root compression

BACKGROUND：It has been shown that interleukin-1 （IL-1） may cause inflammatory reactions, which stimulate the nerve root of patients with lumbar intervertebral disc protrusion and leads to pain. Whether the clinical curative effects of acupuncture in the treatment of lumbar and leg pain are linked to an inhibition of local IL-1 secretion is unknown. OBJECTIVE： To assess the influence of acupuncture on IL-1, this study was designed to verify the effects of acupuncture at the ＂Huatuojiaji （Extra）＂ point on the nerve root in a rat model of lumbar nerve root compression, compared with administration of meloxicam, a non-steroidal anti-inflammatory drug. DESIGN, TIME AND SETTING： Randomized, controlled, molecular biology experiment, performed at the Experimental Center, Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University between September 2005 and April 2006. MATERIALS： Forty healthy adult Sprague Dawley rats of either gender were included in this study. The rats were randomly and evenly divided into the following four groups： normal control, model, acupuncture and meloxicam groups. Lumbar nerve root compression was induced in rats in the model, acupuncture, and meloxicam groups by inserting a specially made silicon rubber slice at the juncture of the L5 nerve root and the dural sac. The acupuncture needle （pattern number N3030, 30#, 1.5 inch） was purchased from Suzhou Medical Appliance Factory, China. IL-1 enzyme linked immunosorbent assay （ELISA） kit was purchased from Santa Cruz Biotechnology, Inc., USA. METHODS： The acupuncture group was acupunctured at the ＂Huatuojiaji＂ point, which is lateral to the compressed L5-6 nerve root, with an acupuncture depth of 0.5 cm. There were two treatment courses, each of involved seven 20-minute acupuncture sessions, one session a day. The meloxicam group was administered intragastrically 3.75 mg/kg meloxicam （5 mg meloxicam /10 mL physiological saline）. Rats in the normal control group and model group received an intragastric administration of 10 mL/kg physiological saline. All administrations were performed once a day. MAIN OUTCOME MEASURES： At day 14 post-surgery, the IL-1 level in the compressed nerve root was determined by a streptavidin-peroxidase （S-P） immunohistochemical method, and IL-1β mRNA expression in the compressed nerve root was simultaneously detected by real-time reverse transcription-polymerase chain reaction. RESULTS： The expression levels of IL-1 and IL-1β mRNA in the L5 nerve root were significantly higher in the model group than in the control group （P 〈 0.01）. However, the expression levels of IL-1 and IL-1β mRNA were significantly lower in the acupuncture and meloxicam groups than in the model group （P 〈 0.05–0.01）. Expression levels of IL-1 and IL-1β mRNA were significantly higher in the acupuncture group than in the meloxicam group （P 〈 0.01）. CONCLUSION： Acupuncture at the ＂Huatuojiaji＂ point decreases the IL-1 level by inhibiting IL-1β mRNA expression to a greater extent than meloxicam administration.

Effect of warm acupuncture on nitric oxide synthase and calcitonin gene-related peptide in a rat model of lumbar nerve root compression

BACKGROUND： Varying degrees of inflammatory responses occur during lumbar nerve root compression. Studies have shown that nitric oxide synthase （NOS） and calcitonin gene-related peptide （CGRP） are involved in secondary disc inflammation. OBJECTIVE： To observe the effects of warm acupuncture on the ultrastructure of inflammatory mediators in a rat model of lumbar nerve root compression, including NOS and CGRP contents. DESIGN, TIME AND SETTING： Randomized, controlled study, with molecular biological analysis, was performed at the Experimental Center, Sixth People＇s Hospital Affiliated to Shanghai Jiao Tong University, between September 2006 and April 2007. MATERIALS： Acupuncture needles and refined Moxa grains were purchased from Shanghai Taicheng Technology Development Co., Ltd., China; Mobic tablets were purchased from Shanghai Boehringer Ingelheim Pharmaceuticals Co., Ltd., China; enzyme linked immunosorbent assay （ELISA） kits for NOS and CGRP were purchased from ADL Biotechnology, Inc., USA. METHODS： A total of 50, healthy, adult Sprague-Dawley rats, were randomly divided into five groups normal, model, warm acupuncture, acupuncture, and drug, with 10 rats in each group. Rats in the four groups, excluding the normal group, were used to establish models of lumbar nerve root compression. After 3 days, Jiaji points were set using reinforcing-reducing manipulation in the warm acupuncture group. Moxa grains were burned on each needle, with 2 grains each daily. The acupuncture group was the same as the warm acupuncture group, with the exception of non-moxibustion. Mobic suspension （3.75 mg/kg） was used in the oral drug group, once a day. Treatment of each group lasted for 14 consecutive days. Modeling and medication were not performed in the normal group. MAIN OUTCOME MEASURES： The ultrastructure of damaged nerve roots was observed with transmission electron microscopy; NOS and CGRP contents were measured using ELISA. RESULTS： The changes of the radicular ultramicrostructure were characterized by Wallerian degeneration; nerve fibers were clearly demyelinated; axons collapsed or degenerated; outer Schwann cell cytoplasm was swollen and its nucleus was compacted. Compared with the normal group, NOS and CGRP contents in the nerve root compression zone in the model group were significantly increased （P 〈 0.01）. Nerve root edema was improved in the drug, acupuncture and the warm acupuncture groups over the model group. NOS and CGRP expressions were also decreased with the warm acupuncture group having the lowest concentration （P 〈 0.01）. CONCLUSION： In comparison to the known effects of Mobic drug and acupuncture treatments, the warm acupuncture significantly decreased NOS and CGRP expression which helped improve the ultrastructure of the compressed nerve root.

THE SIGNIFICANCE OF DERMATOMAL SOMATOSENSORY EVOKED POTENTIALS IN THE DIAGNOSIS OF LUMBOSACRAL NERVE ROOT COMPRESSION

in this study, conical somatosensory evoked potentials (SEPs)following electrical stimulation of the skin of LS and SI dermatomes were recorded cephalically and observed in 19 patients with clinically proved unilateral L5 or S1 nerve root compression, and the results were compared with those of the control group or 20 healthy volunteers and showed that dermatomal SEPs were abnormal in 12 with the rate of 63%,most or which showed abnomalities or the lateral latency difference. It is concluded that dermatomal SEP is a useful addition to the diagnosis or lumbosacral nerve root compression. When the unilateral nerve root is compressed the lateral latency dirference is a most sensitive criterion for indicating abnomality.

Clinical Study on CT-guided Modified Akupotomye in the Treatment of Lumbar Nerve Posterior Branch Compression

Objective: To observe the clinical effect of modified akupotomye closed lysis under CT guidance on compression of posterior lumbar nerve branch.Methods: Patients were diagnosed by HRCT 3-D reconstruction combined with clinical symptoms and signs.After HRCT three-dimensional reconstruction combined with clinical symptoms and signs, the patients were confirmed as posterior lumbar nerve compression.After CT accurate surface positioning, CT-guided modified akupotomye was used for closed lysis of the posterior lumbar nerve branch.Oswestry Dysfunction Index Questionnaire(ODI) was used for quantitative scoring, 7 days before and after treatment and 6 months after treatment.Results: In 62 cases, 20 cases were cured, with 25 cases markedly effective, 11 cases effective, and 36 cases ineffective.The total effective rate was 90.3%.ODI score: Self-paired t test 7 days before after treatment, P < 0.01;Before treatment and 6 months after treatment, self-paired t test(P < 0.01);Self-paired t-test was performed 7 days after treatment and 6 months after treatment(P > 0.05).Conclusion: With CT precise positioning, the modified akupotomye can be used to do closed lysis, to relieve the adhesion and compression, so that the low back pain can be relieved, with good clinical.The akupotomye closed lysis, combined with modern imaging technology has not only achieved good clinical effect, but also can improve the accuracy, safety and scientificity of akupotomye treatment.

Influence of distal portion compression of facial nerve in hemifacial spasm surgery

Objective To study influence of distal portion compression of facial nerve in hemifacial spasm surgery. Methods 120 hemifacial spasm patients were undergone lateral spread response monitoring during microvascular decompression surgery. 39 patients’LSR remained after decompression of the root exit zone of the facial nerve.

Electric stimulation and decimeter wave therapy improve the recovery of injured sciatic nerves

Drug treatment, electric stimulation and decimeter wave therapy have been shown to promote the repair and regeneration of the peripheral nerves at the injured site. This study prepared a Mackinnon’s model of rat sciatic nerve compression. Electric stimulation was given immediately after neurolysis, and decimeter wave radiation was performed at 1 and 12 weeks post-operation. Histological observation revealed that intraoperative electric stimulation and decimeter wave therapy could improve the local blood circulation of repaired sites, alleviate hypoxia of compressed nerves, and lessen adhesion of compressed nerves, thereby decreasing the formation of new entrapments and enhancing compressed nerve regeneration through an improved microenvironment for regeneration. Immunohistochemical staining results revealed that intraoperative electric stimulation and decimeter wave could promote the expression of S-100 protein. Motor nerve conduction velocity and amplitude, the number and diameter of myelinated nerve fibers, and sciatic functional index were significantly increased in the treated rats. These results verified that intraoperative electric stimulation and decimeter wave therapy contributed to the regeneration and the recovery of the functions in the compressed nerves.

Simultaneous laparoscopic and arthroscopic excision of a huge juxta-articular ganglionic cyst compressing the sciatic nerve:A case report

BACKGROUND A large ganglionic cyst extending from the hip joint to the intrapelvic cavity through the sciatic notch is a rare space-occupying lesion associated with compressive lower-extremity neuropathy.A cyst in the pelvic cavity compressing the intrapelvic-sciatic nerve is easily missed in the diagnostic process because it usually presents as atypical symptoms of an extraperitoneal-intrapelvic tumor.We present a case of a huge ganglionic cyst that was successfully excised laparoscopically and endoscopically by a gynecologist and an orthopedic surgeon.CASE SUMMARY A 52-year-old woman visited our hospital complaining of pain and numbness in her left buttock while sitting.The pain began 3 years ago and worsened,while the numbness in the left lower extremity lasted 1 mo.She was diagnosed and unsuccessfully treated at several tertiary referral centers many years ago.Magnetic resonance imaging revealed a suspected paralabral cyst(5 cm×5 cm×4.6 cm)in the left hip joint,extending to the pelvic cavity through the greater sciatic notch.The CA-125 and CA19-9 tumor marker levels were within normal limits.However,the cyst was compressing the sciatic nerve.Accordingly,endoscopic and laparoscopic neural decompression and mass excision were performed simultaneously.A laparoscopic examination revealed a tennis-ball-sized cyst filled with gelatinous liquid,stretching deep into the hip joint.An excisional biopsy performed in the pelvic cavity and deep gluteal space confirmed the accumulation of ganglionic cysts from the hip joint into the extrapelvic intraperitoneal cavity.CONCLUSION Intra-or extra-sciatic nerve-compressing lesion should be considered in cases of sitting pain radiating down the ipsilateral lower extremity.This large juxta-articular ganglionic cyst was successfully treated simultaneously using laparoscopy and arthroscopy.

A STUDY ON THE RELATIONSHIP BETWEEN MAGNETIC STIMULATION MEP AND THE NEUROPATHOLOGY OF THE CHRONIC COMPRESSED LESION OF CAT'S CERVICAL NERVE ROOTS AND THE SIGNIFICANCE OF ITS QUANTITATIVE DIAGNOSIS

In order to observe the damaged nerve successively, we used superficial magnetic stimulation motor evoked potential (MEP) in the pathological model of chronic compressed nerve of the cervical nerve roots of cats. We synthesized various change of the pathomorphology of the nerve damaged to different degrees, and discussed the relationship between the MEP and the pathomorphologic change of chronic compressed nerve roots. The results showed that the initial pathologic change of nerve with myelin was degeneration of myelin shealth. The MEP of the nerve also showed increased latency and dispersed wave forms. After that the axon of the demylinated nerve degenerated, splitted and had a peripheral Wallerian Degeneration. The MEP showed an increased latency along with decreased amplitude. The degree of the MEP's change accompanyed with pathologic change. So we believe that the magnetic compressed nerve. It has some reference value in figuring out the damage by analysing factors.

Anterior subcutaneous transposition of the ulnar nerve improves neurological function in patients with cubital tunnel syndrome

Although several surgical procedures exist for treating cubital tunnel syndrome, the best surgical option remains controversial. To evaluate the efficacy of anterior subcutaneous transposition of the ulnar nerve in patients with moderate to severe cubital tunnel syndrome and to analyze prognostic factors, we retrospectively reviewed 62 patients（65 elbows） diagnosed with cubital tunnel syndrome who underwent anterior subcutaneous transposition. Preoperatively, the initial severity of the disease was evaluated using the Mc Gowan scale as modified by Goldberg： 18 patients（28%） had grade IIA neuropathy, 20（31%） had grade IIB, and 27（42%） had grade III. Postoperatively, according to the Wilson ＆ Krout criteria, treatment outcomes were excellent in 38 patients（58%）, good in 16（25%）, fair in 7（11%）, and poor in 4（6%）, with an excellent and good rate of 83%. A negative correlation was found between the preoperative Mc Gowan grade and the postoperative Wilson ＆ Krout score. The patients having fair and poor treatment outcomes had more advanced age, lower nerve conduction velocity, and lower action potential amplitude compared with those having excellent and good treatment outcomes. These results suggest that anterior subcutaneous transposition of the ulnar nerve is effective and safe for the treatment of moderate to severe cubital tunnel syndrome, and initial severity, advancing age, and electrophysiological parameters can affect treatment outcome.

Increased gene and protein expressions of the transient receptor potential vanilloid receptor 4 following sustained pure mechanical pressure on rat dorsal root ganglion neurons

Dorsal root ganglion （DRG） neurons from newborn Wistar rats cultured in vitro were pressurized with 20, 40, 80 or 120 mm Hg compressive Ioadings （1 mm Hg = 0.133 kPa） for 12, 24, 48 or 72 hours, respectively. The 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide test showed that pressures less than 80 mm Hg had no obvious impact on the activity of DRG neurons. The protein expression levels of transient receptor potential vanilloid receptor 4 （TRPV4）, transient receptor potential vanilloid receptor 1, transient receptor potential channel of melastatin type 8, and transient receptor potential subtype ankyrin 1 were assessed by western blot analysis. The mRNA expression of TRPV4 was assessed by real-time PCR. The results showed that sustained mechanical compression up-regulated TRPV4 mRNA and protein expression in the rat DRG neurons, in a time-dependent fashion. Similar changes were not found in the protein expression of transient receptor potential vanilloid receptor 1, transient receptor potential channel of melastatin type 8, and transient receptor potential subtype ankyrin 1. Images of cells using a laser scanning confocal microscope showed that the sustained mechanical pressure increased the number of responsive DRG neurons and was synergistic on the enhanced Ca^2＋ responses to the TRPV4 phorbol ester agonist 4a-phorbo112, 13-didecanoate and hypotonic solutions. These findings demonstrate that sustained mechanical compressive loading in vitro increases the expression of TRPV4 mRNA and protein in DRG neurons and sensitizes TRPV4 Ca^2＋ signals. Mechanical compression does not impact other ion channels in the transient receptor potential family.

Exploratory use of ultrasound to determine whether demyelination following carpal tunnel syndrome co-exists with axonal degeneration

Carpal tunnel syndrome （CTS） accompanied by secondary axonal degeneration cannot be clearly dis- criminated using the current cross-validated ultrasound severity classification system. This study aimed at exploring cut-off values of ultrasound parameters, including wrist cross-sectional area （W-CSA）, wrist perimeter （W-P）, ratio of cross-sectional area （R-CSA） and perimeter （R-P）, changes of CSA and P from wrist to one third distal forearm （△CSA＆AP） for differentiation. Seventy-three patients （13 male and 60 female） were assigned into group A （demyelination only, n = 40） and group B （demyelination with secondary axonal degeneration, n = 33） based on the outcomes of nerve conduction studies （NCS）. Receiver Operative Characteristics （ROC） curves were plotted to obtain sensitivity, specificity, and accuracy of cut- off values for all the ultrasound parameters. The overall identified cut-off values （W-CSA 12.0 mm2, W-P 16.27 mm, R-CSA 1.85, R-P 1.48, △CSA 6.98 mm2, △P 5.77 mm） had good sensitivity （77.1-88.6%）, fair specificity （40-62.2%） and fair-to-good accuracy （0.676-0.758）. There were also significant differences in demographics （age and severity gradation, P 〈 0.001）, NCS findings （wrist motor latency and conduction velocity, P 〈 0.0001; wrist motor amplitude, P 〈 0.05; distal sensory latency, P 〈 0.05; sensory amplitude, P 〈 0.001） and ultrasound measurements （W-CSA, W-P, R-CSA, R-P, △CSA＆△P, P 〈 0.05） between groups. These findings suggest that ultrasound can be potentially used to differentiate demyelinating CTS with sec- ondary axonal degeneration and provide better treatment guidance.

Recalcitrant cubital tunnel syndrome

Ulnar nerve neuropathy at the elbow represents the second most frequent compression neuropathy of the upper extremity.Of the five different anatomical areas responsible for ulnar nerve compression at the elbow region,the epitrochlear-olecranon channel and Osborne’s arcade are the most common.An additional cause of nerve damage is a dynamic process in which the ulnar nerve dislocates anteriorly at the epitrochlear-olecranon level during elbow flexion,partially or completely,causing nerve friction and constriction leading to chronic neuropathic pain.Failure after primary surgery is generally secondary to procedural errors or technical omissions,frequently represented by incomplete nerve decompression,failure to recognize nerve instability after nerve decompression,loosening of the nerve anchor after superficial nerve transposition with consequent spontaneous nerve relocation in the epitrochlear-olecranon channel,perineural fibrosis and neurodesis,which creates new nerve compression.In association with the clinical evaluation,electromyography studies,magnetic resonance imaging and ultrasound are useful tools that may aid in the decision-making process when considering revision surgery.Superficial anterior transposition is the most commonly employed technique but also has a high failure rate,as opposed to anterior deep transposition that is the method of choice for many surgeons despite being more technically demanding.The results of revision surgery following recalcitrant ulnar nerve compression at the elbow are inferior to those obtained after primary surgery.Nonetheless,the clinical advantages remain relevant provided that the revision surgery is performed by an expert surgeon.To avoid misinterpretation,the patient is completely informed of the quality of results.