Causes, symptoms, and treatments of nerve entrapments around the elbow: Current concepts

The elbow is a joint extremely susceptible to stiffness, even after a trivial trauma. As for other joints, several factors can generate stiffness such as immobilisation, joint incongruity, heterotopic ossification, adhesions, or pain. Prolonged joint immobilisation, pursued to assure bony and ligamentous healing, represents the most acknowledged risk factor for joint stiffness. The elbow is a common site of nerve entrapment syndromes. The reasons are multifactorial, but peculiar elbow anatomy and biomechanics play a role. Passing from the arm into the forearm, the ulnar, median, and radial nerves run at the elbow in close rapport with the joint, fibrous arches and through narrow fibro-osseous tunnel. The elbow joint, in fact, has a large range of flexion which exposes nerves lying posterior to the axis of rotation to traction and those anterior to compression.

Demystifying the Radial Nerve The Management of Radial Nerve Palsy in the Setting of Humeral Shaft Fracture

The association of radial nerve palsy and humeral shaft fracture is well known. Primary exploration and fracture fixation is recommended for open fractures and vascular injury while expectant management remains the standard of care for closed injuries. In the absence of nerve recovery, exploration and reconstruction is recommended 3 to 5 months following injury. When direct repair or nerve grafting is unlikely to achieve a suitable outcome, nerve and tendon transfers are potential options for the restoration of wrist and finger extension.

Case-based report of graded motor imagery experience in traumatic brachial plexus injury: The art of moving without moving

BACKGROUND

We reported a 24-year-old woman who sustained multiple upper limb injuries after a traffic accident in March 2017. She sustained a C7-T1 brachial plexus injury and radial nerve injury on the left side diagnosed in November 2017. The patient underwent radial nerve reconstruction. The patient began her comprehensive therapy program in January 2018.

PURPOSE

To describe the use of graded motor imagery (GMI) and outcomes after traumatic brachial plexus palsy. We presented changes in electromyographic (EMG) activity of target muscles during task execution and functional status following 10-session GMI therapy.

STUDY DESIGN

Case report.

METHODS

The program included 4 sessions of motor imagery and 6 sessions of a combination of motor imagery and mirror therapy.

RESULTS

The patient successfully participated in the program with reported improvements in EMG activity, functional status, emotional well-being, and body awareness.

CONCLUSIONS

GMI therapy appears to have peripheral motor effects, including altered surface EMG activity and contributes to a favorable outcome in the functional level of the affected arm. An improved emotional state and awareness of the affected hand could have a positive effect on function. Future long-term randomized controlled trials are needed to investigate the cumulative peripheral effects of treatment of graded motor imagery and the effects of variables mediating its effects on functional performance in patients with nerve injury.

Radial Nerve Palsy Associated with Humeral Shaft Fractures in Children

Background

This is the first systematic review of the relationship between humeral shaft fractures and radial nerve palsy in children. The present comprehensive review is aimed at identifying important clinical findings between humeral diaphysis fractures and radial nerve injuries and assessing the effects of treatment.

Methods

We searched electronic bibliographic databases, including PubMed, the Cochrane Library, Scopus, and Web of Knowledge, until March 2022. This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the patients, interventions, comparisons, outcomes guidelines.

Results

We identified 23 original papers, of which 10 were eligible for further analysis. Cases of 32 young patients with radial nerve palsy were identified and analyzed. The prevalence of radial nerve palsy was 4.34% (eight cases out of 184 patients with humeral shaft fractures). The radial nerve was most often associated with a simple transverse fracture (12A3, 17 cases (65.4%)).

Conclusions

Radial nerve injury in humeral shaft fractures in children is rare, with a frequency of 4.34%. We highly recommend early surgical nerve exploration with transverse fractures in the distal third segment combined with primary radial palsy. Furthermore, we recommend making thoughtful decisions regarding early nerve exploration in the Holstein-Lewis fractures. In addition, consideration of early surgical nerve exploration in fractures resulting from high-energy trauma and open fractures despite their morphology is recommended.

Postoperative analgesia after surgical repair of distal radius fracture: a randomized comparison between distal peripheral nerve blockade and surgical site infiltration

BACKGROUND

Pain following open reduction and internal fixation of distal radius fracture (DRF) can be significant. This study compared the intensity of pain up to 48 hours after volar plating for DRF, associated to either an ultrasound guided distal nerve block (DNB) or surgical site infiltration (SSI).

METHODS

In this prospective single blind randomized study, 72 patients scheduled for DRF surgery under 1.5% lidocaine axillary block were allocated to receive, at the end of surgery, either an ultrasound-guided median and radial nerves block with ropivacaine 0.375% (DNB) performed by the anesthesiologist or a SSI with the same drug regimen, performed by the surgeon. Primary outcome was the duration between analgesic technique (H0) and pain reappearance (Numerical Rating Scale (NRS 0-10)>3). Secondary outcomes were the quality of analgesia, the quality of sleep, the magnitude of motor blockade, and the patient satisfaction. The study was built on a statistical hypothesis of equivalence.

RESULTS

Fifty-nine patients were included in the final per-protocol analysis (DNB=30, SSI=29). Time to reach NRS>3 was (in median [95%CI]) 267 min [155;727] and 164 min [120;181] respectively after DNB and SSI (difference=103 min [-22;594] - rejection of equivalence hypothesis). Pain intensity throughout the 48 hours, quality of sleep, opiate consumption, motor blockade and patient satisfaction was not significantly different between groups.

CONCLUSIONS

Although DNB provides a longer analgesia than SSI, both techniques gave comparable level of pain control during the first 48 hours after surgery, without any difference in the incidence of side effects or patient satisfaction.

Distal locking technique affects the rate of iatrogenic radial nerve palsy in intramedullary nailing of humeral shaft fractures

BACKGROUND

Intramedullary humeral nailing is a common and reliable procedure for the treatment of humeral shaft fractures. Radial nerve palsy is a common complication encountered in the treatment of this pathology. The radial nerve runs from posterior to anterior at the lateral aspect of the distal humerus. Hence, there is reason to believe that due to the anatomic vicinity of the radial nerve in this area, lateral-medial distal locking in intramedullary nailing of the humerus may be associated with a greater risk for iatrogenic radial nerve injury compared to anterior-posterior locking.

QUESTIONS/PURPOSE

To assess whether the choice of distal locking (lateral-medial versus anterior-posterior distal locking) in intramedullary humeral nailing of humeral shaft fractures affects the risk for iatrogenic radial nerve injury.

PATIENTS AND METHODS

Overall, 203 patients (116 females, mean age 64.3 ± 18.6 years), who underwent intramedullary nailing of the humerus between 2000 and 2020 at a single level-one trauma center, met the inclusion criteria and were analyzed in this retrospective case-control study. Patients were subdivided into two groups according to the distal locking technique.

RESULTS

Anterior-posterior locking was performed in 176 patients versus lateral-medial locking in 27 patients. We observed four patients with iatrogenic radial nerve palsy in both groups. Risk for iatrogenic radial nerve palsy was almost 7.5 times higher for lateral-medial locking (OR 7.48, p = 0.006). There was no statistically significant difference regarding intraoperative complications, union rates or revision surgeries between both groups.

CONCLUSIONS

Lateral-medial distal locking in intramedullary nailing of the humerus may be associated with a greater risk for iatrogenic radial nerve palsy than anterior-posterior locking. Hence, we advocate for anterior-posterior locking.

LEVEL OF EVIDENCE

Level III retrospective comparative study.

Is there any difference between anterior and posterior approach for the spinal accessory to suprascapular nerve transfer? A systematic review and meta-analysis

Dual nerve transfer of the spinal accessory nerve to the suprascapular nerve (SAN-SSN) and the radial nerve to the axillary nerve is considered to be the most feasible method of restoration of shoulder abduction in brachial plexus injuries. Supraspinatus muscle plays an important role in the initiation of abduction and its functional restoration is crucial for shoulder movements. There are two possible approaches for the SAN-SSN transfer: the more conventional anterior approach and the posterior approach in the area of scapular spine, which allows more distal neurotization. Although the dual nerve transfer is a widely used method, it is unclear which approach for the SAN-SSN transfer results in better outcomes. We conducted a search of English literature from January 2001 to December 2021 using the PRISMA guidelines. Twelve studies with a total 142 patients met our inclusion criteria. Patients were divided into two groups depending on the approach used: Group A included patients who underwent the anterior approach, and Group B included patients who underwent the posterior approach. Abduction strength using the Medical Research Scale (MRC) and range of motion (ROM) were assessed. The average MRC grade was 3.57 ± 1.08 in Group A and 4.0 ± 0.65 (p = 0.65) in Group B. The average ROM was 114.6 ± 36.7 degrees in Group A and 103.4 ± 37.2 degrees in Group B (p = 0.247). In conclusion, we did not find statistically significant differences between SAN-SSN transfers performed from the anterior or posterior approach in patients undergoing dual neurotization technique for restoration of shoulder abduction.

Optimal timing of needle electromyography to diagnose lesion severity in traumatic radial nerve injury

INTRODUCTION/AIMS

In patients with traumatic radial nerve injury (RNI), the chance of spontaneous recovery must be balanced against the benefits of early surgical reconstruction. We aimed to explore the time-specific value of needle electromyography (NEMG) to diagnose nerve lesion severity.

METHODS

In this retrospective diagnostic accuracy study at Leiden Nerve Center, patients at least 12 years of age with RNI caused by fractures or fracture treatment were included. The sensitivity and specificity of the patients' first NEMG examination were assessed, stratified by the timing after the nerve injury. The absence of motor unit potentials (MUPs) in muscles distal to the nerve lesion was considered a positive test result. Lesion severity was dichotomized to moderate injury (spontaneous Medical Research Council grade ≥3 recovery) or severe injury (poor spontaneous recovery or surgical confirmation of a mainly neurotmetic lesion).

RESULTS

Ninety-five patients were included in our study. The sensitivity of NEMG to detect severe RNI was 75.0% (3 of 4) in the fourth, 66.7% (2 of 3) in the fifth, and 66.7% (2 of 3) in the sixth month after the nerve injury. The specificity in the first to the sixth month was 0.0% (0 of 1), 50.0% (2 of 4), 77.3% (17 of 22), 95.5% (21 of 22), 95.8% (23 of 24), and 100.0% (12 of 12), respectively.

DISCUSSION

The specificity of NEMG is higher than 95% and therefore clinically relevant from the fourth month after the nerve injury onward. Absence of MUPs at this time can be considered an indication to plan nerve exploration. Moreover, the presence of MUPs on NEMG does not completely exclude the necessity for surgical reconstruction.

Spatial Anatomy of the Radial Nerve in the Extended Deltopectoral Approach

The goal of this study was to define safe zones to prevent radial nerve injury in an extended deltopectoral approach. Relative distances of the upper margin (UMRN) and lower margin (LMRN) of the radial nerve to the proximal and distal borders of the pectoralis major and deltoid insertions were measured in 20 cadaveric arms. Four proximal humeral zones were identified (zone I, proximal border of the pectoralis major tendon to the proximal border of the deltoid tendon; zone II, proximal border of the deltoid tendon to the distal border of the pectoralis major tendon; zone III, distal border of the pectoralis major tendon to the distal border of the deltoid tendon; and zone IV, distal to the distal border of the deltoid tendon). On fluoroscopic measurement, mean distances between the UMRN and the proximal border of the pectoralis major tendon and the proximal border of the deltoid tendon were 71.6±2.1 mm and 26.2±2.5 mm, respectively. The incidence of the radial nerve in the spiral groove within each defined zone was as follows: zone I, 0%; zone II, 50%; zones III and IV, 100%. There was a significant association between anatomic zone and radial nerve entry into the spiral groove, χ²(3, N=88)=64.53, P<.001. The proximal border of the pectoralis major tendon to the proximal border of the deltoid tendon (zone I) is a safe location to avoid injury to the radial nerve. We recommend placing cerclage wires proximal to zone I from lateral to medial to avoid entrapment of the radial nerve. [Orthopedics. 2023;46(1):e31-e37.].

Radial Tunnel Syndrome: Case Report and Comprehensive Critical Review of a Compression Neuropathy Surrounded by Controversy

Radial tunnel syndrome (RTS) is an uncommon controversial entity thought to cause chronic lateral proximal forearm pain due to compression of the deep branch of the radial nerve, without paralysis or sensory changes. Diagnostic confusion for pain conditions in this region results from inconsistent definitions, terminology, tests, and descriptions in the literature of RTS and "tennis elbow," or lateral epicondylitis. A case of bilateral RTS with signs discordant with traditionally used clinical diagnostic tests was successfully relieved with surgical decompression and led us to perform a comprehensive critical review of the condition. We delineate the controversy surrounding its diagnosis and aim to facilitate appropriate management and identify other areas for further study in this controversial condition. Clinical validity and evidence of anatomical rationale for the traditionally used Maudsley's provocative test is unclear in diagnosis of RTS or in chronic lateral elbow pain, if at all. Neither imaging nor electrophysiological studies contribute to a clinical diagnosis which is supported by short-term improvement after an injection with long-acting local anesthetic and corticosteroid. Accurate diagnosis and treatment of RTS can significantly improve quality of life, but validity and evidence for traditional clinical tests and definitions must be clarified.

Nerve transfers in the forearm: potential use in spastic conditions

PURPOSE

Deformities of the spastic upper limb result frequently from the association of spasticity, muscle contracture and muscle imbalance between strong spastic muscles and weak non-spastic muscles. This study was designed to evaluate the feasibility of combining selective neurectomy of the usual spastic and strong muscles together with transfer of their motor nerves to the usual weak muscles, to improve wrist and fingers motion while decreasing spasticity.

METHODS

Twenty upper limbs from fresh frozen human cadavers were dissected. All motor branches of the radial and median nerve for the forearm muscles were identified. We attempted all possible end-to-end nerve transfers between the usually strong "donor" motor branches, namely FCR and PT, and the usually weak "recipient" motor branches (ERCL, ECRB, PIN, AIN).

RESULTS

 The PT had two nerve branches in 80%, thus allowing selective neurectomy. The proximal PT branch could be anastomosed end-to-end in 45% (AIN) to 85% (ECRL) of cases with the potential recipient branches. The distal PT branch could be anastomosed end to end to all potential recipient nerves. The FCR had a single branch in all cases. End-to-end anastomosis was possible in 90% for the ECRL and in 100% for all other recipient branches, but sacrificed all FCR innervation, ruling out hyperselective neurectomy.

CONCLUSION

 Selective neurectomies can be associated with distal nerve transfers at the forearm level in selected cases. The motor nerve to the PT is the best donor for nerve transfer combined with selective neurectomy, transferred to the ECRL, ECRB, PIN or AIN.

Is superficial radial nerve affected in patients with hand osteoarthritis?

INTRODUCTION

Patients with superficial radial neuropathy (SRN) have pain and abnormal sensation on the hand similar to hand osteoarthritis (HOA).

PURPOSE OF THE STUDY

The aim of the present study was to evaluate the presence of SRN in patients with HOA and to determine the factors associated with electrophysiological parameters of the radial nerve.

STUDY DESIGN

This is a case-control study.

METHODS

A total of 138 patients were included in this study. Only the dominant hand of each patient was evaluated. Patients were divided into 2 groups: Group 1 (without SRN) or Group 2 (with SRN) by electrophysiological examination. The presence of osteoarthritis in the first carpometacarpal (1st CMC) joint was investigated. Radiological features of the hands were evaluated with Kellgren-Lawrence grading system. Sonographically, the presence of synovitis in the 1st CMC joint was examined with gray scale and synovial blood flow signal by power Doppler imaging. Erosion and osteophyte scoring were performed for 15 joints. The 1st extensor compartment of wrist's cross-sectional area was measured.

RESULTS

SRN was detected in 68.8% of the patients. High Kellgren-Lawrence scores (P = .027), presence of synovitis in the 1st CMC joint (P = .003), and increased cross-sectional area of the 1st extensor compartment of wrist (P = .005) were found to be independent risk factors for reduced superficial radial nerve conduction velocity.

CONCLUSIONS

Sensory symptoms in patients with HOA might be due to the involvement of the superficial branch of the radial nerve.

Radial Nerve Paralysis in Diaphyseal Fractures of the Humerus

One of the most common complications associated with a diaphyseal humeral fracture is the development of a radial nerve injury. We conducted a study to analyze the degree of recovery and prognostic factors associated with radial nerve palsy in patients with diaphyseal humerus fractures. We retrospectively analyzed 28 patients who presented to the Hospital La Fe, Valencia, Spain, with a diaphyseal humerus fracture associated with radial nerve injury between 2010 and 2020. A total of 14.3% (n = 4) of the patients in our cohort had open fractures and 85.7% (n = 24) had closed fractures. There were no statistically significant differences between the type of treatment and the type of fracture (p = .13). There were also no significant differences between the type of treatment and recovery time (p = .42). There was a statistically significant difference (p = .04) in the mean recovery time for patients with preoperative radial nerve injuries (11.9 months) compared with patients who sustained a radial nerve injury secondary to surgical repair of the fracture (8.6 months). The difference in recovery time between patients with open and closed fractures was not statistically significant (p = .3). Results of the study showed that the type of fracture (i.e., open or closed) did not affect radial nerve palsy recovery time. Patients who sustain radial nerve injuries secondary to a surgical repair have a shorter recovery time than patients who sustain primary radial nerve injuries.

Dedifferentiation of radial glia-like cells is observed in in vitro explants of holothurian radial nerve cord

BACKGROUND

Among animal phyla, some of the least studied nervous systems are those of the phylum Echinodermata. Part of the problem lies in that most of their nervous components are embedded in the body wall that has calcareous skeletal components.

NEW METHOD

We have developed a novel technique for the successful isolation of the radial nerve cords (RNCs) and an in vitro system where the isolated RNCs can be cultured and are amenable to experimental manipulation. Here we use this system to isolate the RNC of the sea cucumber Holothuria glaberrima as a way to extend our studies on its regeneration capabilities.

RESULTS

The RNCs can be isolated from the surrounding tissues by collagenase treatment. The explants obtained following enzymatic dissociation can be kept in culture for up to 2 weeks. Histological and immunohistochemical studies show that the explants maintain a stable number of cells with little proliferation or apoptosis throughout the culture incubation period. The main change observed in RNCs in vitro is a progressive dedifferentiation of radial glia-like cells. This dedifferentiation corresponds to the first step in the regeneration response to injury that has been described in vivo.

COMPARISON WITH EXISTING METHODS

There are no existing methods to isolate and culture echinoderm radial nerve cord.

CONCLUSIONS

The described protocol provides a unique tool to obtain easily accessible RNC from holothurians to perform cellular, biochemical, and genomic experiments in the echinoderm nervous system without interference of adjacent tissues. The technique provides a unique opportunity to study the dedifferentiation response associated with the regeneration of the nervous system in echinoderms.

The Window Test: a simple bedside method to detect radial deviation of the wrist commonly seen in posterior interosseous nerve palsy

BACKGROUND

Posterior interosseous nerve palsy (PINP) is a disorder caused by damage to the posterior interosseous nerve, resulting in weak extension of the wrist and fingers as well as radial deviation of the wrist.

METHODS

In this study, a new type of evaluation for PINP was analyzed in hopes of increasing ease of diagnosis and earlier detection of the disorder. The "Window Test" is performed by the examiner laying hands on the ulnar aspect of the patient's pronated forearm while the latter is trying to extend the wrist. A positive test is observed when a gap (window) appears between the examiner's forearm and the patient's hand. Lay people, medical students, residents, and practicing providers were assessed prospectively on their ability to correctly diagnose PINP by observing one hand, both hands, and by using the Window Test.

RESULTS

The Window Test was consistently found to be the most effective method of evaluation as it increased the accuracy of diagnoses in all groups surveyed. Additionally, case studies were performed using the Window Test on patients, further demonstrating the efficacy of the test by confirming wrist radial deviation.

CONCLUSION

The Window Test introduces a reference frame, making it easier to assess wrist radial deviation and offering a simple evaluation that can be administered by virtually anyone. These findings indicate that the implementation of the Window Test will increase the accuracy and effectiveness of PINP diagnosis, thus allowing early diagnosis and better management.

Relationship between incidence of postoperative radial nerve palsy and surgical experience in the treatment of humeral shaft fractures through a posterior triceps splitting approach: A retrospective study

OBJECTIVE

The aim of this study was to investigate the incidence of postoperative radial nerve palsy (PORNP) after the surgical treatment of humeral shaft fractures through a posterior triceps splitting approach by a single surgeon's experience in a consecutive case series from a single trauma center.

METHODS

In this retrospective study, a total of 118 patients (82male, 36 female;mean age = 48 years, age range = 16 - 80 years)who underwent open reduction and plate fixation through posterior triceps splitting approach due to humeral shaft fractures at a level I trauma center were included. Level of the fractures was categorized as the proximal third, middle third, and distal third of the diaphysis, and then all the fractures were classified according to the AO/OTA classification system. The trend of incidence of PORNP was investigated. All the operations were performed by a single surgeon. The recovery time of PORNP was also recorded.

RESULTS

There were 13 cases of proximal third, 67 cases of middle third, and 38 cases of distal third fracture. Based on AO/OTA classification, there were 29 cases of A1-type, 23 cases of A2-type, 42 cases of A3-type, 17 cases of B2-type, 3 cases of B3-type, and 4 cases of C2-type fracture. The overall incidence of PORNP was 11% (13 cases). All the PORNP cases fully recovered within 10.3 ± 10.4 weeks (range = 1 - 44) with conservative treatment. Incidence of PORNP significantly decreased with increase in surgical experience (P = 0.009). The incidence of radial nerve palsy was not significantly related to the level of the fracture (P = 0.199). The incidence of radial nerve palsy was not significantly related with the fracture pattern according to AO/OTA classification (P = 0.659).

CONCLUSION

Evidence from this study has shown that the incidence of PORNP following the posterior triceps splitting approach for the treatment of humeral shaft fractures is significantly associated with the surgeon's experience.

LEVEL OF EVIDENCE

Level IV, Therapeutic Study.

Prospective Home-use Study on Non-invasive Neuromodulation Therapy for Essential Tremor

Highlights

This prospective study is one of the largest clinical trials in essential tremor to date. Study findings suggest that individualized non-invasive neuromodulation therapy used repeatedly at home over three months results in safe and effective hand tremor reduction and improves quality of life for many essential tremor patients.

Background

Two previous randomized, controlled, single-session trials demonstrated efficacy of non-invasive neuromodulation therapy targeting the median and radial nerves for reducing hand tremor. This current study evaluated efficacy and safety of the therapy over three months of repeated home use.

Methods

This was a prospective, open-label, post-clearance, single-arm study with 263 patients enrolled across 26 sites. Patients were instructed to use the therapy twice daily for three months. Pre-specified co-primary endpoints were improvements on clinician-rated Tremor Research Group Essential Tremor Rating Assessment Scale (TETRAS) and patient-rated Bain & Findley Activities of Daily Living (BF-ADL) dominant hand scores. Other endpoints included improvement in the tremor power detected by an accelerometer on the therapeutic device, Clinical and Patient Global Impression scores (CGI-I, PGI-I), and Quality of Life in Essential Tremor (QUEST) survey.

Results

205 patients completed the study. The co-primary endpoints were met (p≪0.0001), with 62% (TETRAS) and 68% (BF-ADL) of 'severe' or 'moderate' patients improving to 'mild' or 'slight'. Clinicians (CGI-I) reported improvement in 68% of patients, 60% (PGI-I) of patients reported improvement, and QUEST improved (p = 0.0019). Wrist-worn accelerometer recordings before and after 21,806 therapy sessions showed that 92% of patients improved, and 54% of patients experienced ≥50% improvement in tremor power. Device-related adverse events (e.g., wrist discomfort, skin irritation, pain) occurred in 18% of patients. No device-related serious adverse events were reported.

Discussion

This study suggests that non-invasive neuromodulation therapy used repeatedly at home over three months results in safe and effective hand tremor reduction in many essential tremor patients.

Can Ultrasonography Be Useful in Planning Surgery for De Quervain Tenosynovitis?: A Prospective Study With Emphasis on Detection of the Superficial Radial Nerve and Dominant Pathologic Tendon

OBJECTIVES

We performed preoperative ultrasonography (US) to detect the anatomic course of the superficial radial nerve (SRN) and dominant pathologic tendon of the first extensor compartment in de Quervain tenosynovitis.

METHODS

We prospectively studied 27 patients (29 wrists) with de Quervain tenosynovitis who underwent surgical release of the first extensor compartment. Preoperatively, US was performed to evaluate the presence of the dominant pathologic tendon and the septum in the subcompartment, number of SRNs in the area of the surgical incision, and anatomic running course of the SRN. These variables were also checked intraoperatively. Cohen κ statistics were calculated to investigate agreement between US and surgical field findings.

RESULTS

There were 7 men and 20 women (mean age, 47.8 years; range, 26-67 years). For the dominant pathologic tendon, there were 2 cases (6.9%) of an abductor pollicis longus, 11 cases (37.9%) of an extensor pollicis brevis, and 16 cases (55.2 %) of a nondominant tendon (κ = 0.94). For the subcompartment, there were 10 cases (34.5%) without a septum, 8 (27.6%) with an incomplete septum, and 11 (37.9%) with a complete septum (κ = 0.95). Most SRNs crossed over the first extensor compartment (κ = 0.78).

CONCLUSIONS

Preoperative US can be useful in detecting the anatomic running course of the SRN and dominant pathologic tendon before surgery for de Quervain tenosynovitis. Classifying the anatomic course of the SRN could be essential to planning surgery, and it could be helpful to prevent injury of the SRN during surgery.

Anatomical Basis for Injection around First Dorsal Compartment of the Wrist: A Fresh Cadaveric Study

BACKGROUND

It is important to understand the anatomical relationship between the medial and lateral branches of superficial radial nerve (SRN) and the first dorsal compartment to prevent and minimize possible injury to these nerves during various procedures around the tip of radial styloid process (RSP).

OBJECTIVE

To delineate the anatomical location of the SRN in relation to the extensor pollicis brevis (EPB) and abductor pollicis longus (APL) tendons.

STUDY DESIGN

Observational study.

SETTING

Academic medical center.

METHODS

The width of the first dorsal compartment, distance between the EPB tendon and the closest medial branch of the SRN, and distance between the APL tendon and the closest lateral branch of the SRN were measured. The distances were measured at the RSP (the tip of the RSP) and RSP+1 (1 cm proximal to the tip of the RSP) levels.

RESULTS

The median distances between the EPB tendon and the closest medial branch of the SRN at the RSP and RSP+1 were 6.0 mm (range: 1.6 - 11.0 mm) and 3.2 mm (range: -2.0- 9.4 mm), respectively. The median distances from the APL tendon to the closest lateral branch of the SRN at the RSP and RSP+1 were -2.0 mm (range: -9.0- 8.4 mm) and 1.0 mm (range: -7.2- 8.0 mm), respectively. A high percentage of overlap (up to 59%) was observed between the lateral branch of the SRN and the APL tendon.

LIMITATION

This study is limited by its small sample size.

CONCLUSION

Due to the anatomical proximity of the branches of the SRN and the first dorsal compartment around the RSP, physicians must be cautious during procedures near this location. It is important to approach from above the EPB, rather than from above the APL, when performing blind procedures, although ultrasound guidance is preferable.

Combined Spinal Cord Stimulation and Peripheral Nerve Stimulation for Brachial Plexopathy: A Case Report

Brachial plexopathy usually results from an iatrogenic brachial plexus injury and can sometimes cause severe chronic pain and disability. There are a number of possible treatments for this condition, including medication, physical therapy, nerve blocks, and neuromodulation, but they are not always successful. Recently, combined spinal cord stimulation (SCS) and peripheral nerve stimulation (PNS) have been tried for various chronic pain diseases because of their different mechanisms of action.Here, we describe the case of a 54-year-old man who was diagnosed with brachial plexopathy 8 years ago. He underwent video-assisted thoracoscopic surgery to remove a superior mediastinal mass. However, his brachial plexus was damaged during the surgery. Although he had received various treatments, the pain did not improve. For the management of intractable severe pain, he underwent SCS 2 years ago, which initially reduced his pain from numeric rating scale (NRS) 10/10 to NRS 4 - 5/10, but the pain then gradually increased, reaching NRS 8/10, 6 months ago. At that time, he was refractory to other treatments, and we therefore applied PNS in combination with SCS. The PNS electrode was positioned on the radial nerve under ultrasound guidance. After combined PNS and SCS, his background pain disappeared, although a breakthrough pain (NRS 3 - 4/10) was caused intermittently by light touch. Furthermore, the patient's need for analgesics decreased, and he was satisfied with the outcome of this combined treatment. We concluded that combined SCS and PNS is a very useful treatment modality, which can stimulate the target nerve both directly and indirectly, and hence, relieve pain from brachial plexopathy.

Pulsed radiofrequency on radial nerve under ultrasound guidance for treatment of intractable lateral epicondylitis

Lateral epicondylitis is a painful and functionally limiting disorder. Although lateral elbow pain is generally self-limiting, in a minority of people symptoms persist for a long time. When various conservative treatments fail, surgical approach is recommended. Surgical denervation of several nerves that innervate the lateral humeral epicondyle could be considered in patients with refractory pain because it denervates the region of pain. Pulsed radiofrequency is a minimally invasive procedure that improves chronic pain when applied to various neural tissues without causing any significant destruction and painful complication. This procedure is safe, minimally invasive, and has less risk of complications relatively compared to the surgical approach. The radial nerve can be identified as a target for pulsed radiofrequency lesioning in lateral epicondylitis. This innovative method of pulsed radiofrequency applied to the radial nerve has not been reported before. We reported on two patients with intractable lateral epicondylitis suffering from elbow pain who did not respond to nonoperative treatments, but in whom the ultrasound-guided pulsed radiofrequency neuromodulation of the radial nerve induced symptom improvement. After a successful diagnostic nerve block, radiofrequency probe adjustment around the radial nerve was performed on the lateral aspect of the distal upper arm under ultrasound guidance and multiple pulsed treatments were applied. A significant reduction in pain was reported over the follow-up period of 12 weeks.

[EFFECTIVENESS COMPARISON OF EXTERNAL FIXATION AND VOLAR LOCKING COMPRESSION PLATE IN TREATMENT OF DISTAL RADIUS FRACTURES OF TYPE C]

OBJECTIVE

To compare the effectiveness of external fixation and volar locking compression plate in the treatment of distal radius fractures of type C.

METHODS

Between March 2012 and March 2013, 122 patients with distal radius fractures of type C were enrolled in the prospective randomized study. Fractures were treated by external fixation in 61 patients (external fixation group) and by open reduction and internal fixation using a volar locking compression plate in 61 patients (plate group). There was no significant difference in age, gender, fracture side, weight, height, body mass index, fracture type, and interval of injury and operation between 2 groups (P > 0.05). The blood loss, operation time, hospitalization days, fracture union time, wrist function, and complications were compared between 2 groups. And the quality of reduction was observed, including volar tilting angle, ulnar deviation, radial height, and articular reduction.

RESULTS

The blood loss, operation time, and hospitalization days in plate group were significantly higher than those in external fixation group (P < 0.05). All of the patients in both groups were followed up 12-28 months. Postoperative complications occurred in 4 patients (6.6%) of external fixation group (pin tract infection in 2 cases and radial nerve neuritis in 2 cases) and in 5 patients (8.2%) of plate group (wound infection in 1 case, carpal tunnel syndrome in 2 cases, and tendon rupture in 2 cases), showing no significant difference between 2 groups (P = 0.500). The X-ray films showed fracture healing in all patients of 2 groups; the union time of plate group was significantly longer than that of external fixation group (P < 0.05). At last follow-up, there was no significant difference in ulnar deviation and radial height between 2 groups (P > 0.05), but the volar tilting angle of plate group was significantly larger than that of external fixation group (P < 0.05). There was no significant difference in wrist function and articular reduction between 2 groups (P > 0.05).

CONCLUSION

For distal radius fractures of type C, the use of external fixation or volar locking compression plate can obtain satisfactory clinical outcomes, but the external fixation has the advantages of less invasion, shorter hospitalization days, minor complications, and faster fracture union.

Nerve stimulation under ultrasound guidance expedites onset of axillary brachial plexus block

BACKGROUND

Axillary block is popular technique in upper extremity surgery. Nerve stimulation is used for location of nerves to provide effective blockade. The advent of ultrasound imaging technique in regional anaesthesia has increased the accuracy of needle placement and local anaesthetic deposition around the nerve. The aim of this study is to find out if the nerve stimulation technique with ultrasound guidance has advantages over sole nerve stimulation technique. The outcome measures studied were onset of sensory and motor block, procedure time, number of skin puncture, vascular puncture and paresthesia during nerve stimulation.

METHODS

This is a prospective randomized comparative study conducted in KMCTH from June 2009 to March 2010 on patients of American Society of Anaesthesiologist I and II requiring upper arm surgery under axillary block. The study comprised of two groups: ultrasound with nerve stimulation group (n=35) and nerve stimulation group (n=35). 24 ml of Bupivacaine 0.5% with injection Dexamethasone 4 mg was used to block the individual four nerves with 6 ml of the local anaesthetic solution per nerve namely ulnar, radial, median and musculocutaneous. The data were recorded by blinded observer. In case of partial block or block failure, the patients were supplemented with Fentanyl or subjected to laryngeal mask placement.

RESULTS

Demographic characteristics (age, weight) in either group were similar (p>0.05). The male and female ratio (M: F) in ultrasound with nerve stimulation group was 12:16. The ratio was 18:17 in nerve stimulation group. The onset of complete sensory block was earlier and the onset of motor block was faster in ultrasound with nerve stimulation group than in sole nerve stimulation group (p=0.001). Ultrasound guidance decreased the number of skin puncture during the nerve stimulation, p= 0.02. The incidence of paresthesia was encountered during nerve location (14%), which could be minimized using ultrasound (7%). The success rate of the block was 93% with ultrasound assistance. The procedure time was not different in both techniques. The surgery duration was not significant statistically in either of the group, p=0.715.

CONCLUSIONS

This study showed that the onset of sensory and motor block was faster with ultrasound assistance nerve stimulation. Complications can be decreased with the use of ultrasound in axillary block.

Single vs. double stimulation during a lateral sagittal infraclavicular block

BACKGROUND

The objective of this study was to evaluate the influence of single vs. dual control during an ultrasound-guided lateral sagittal infraclavicular block on the efficacy of sensory block and the time of block onset.

METHODS

In a prospective manner, 60 adult patients scheduled for distal upper limb surgery were randomly allocated to single (Group S) or double stimulation (Group D) groups. A local anesthetic (LA) mixture of 20 ml of levobupivacaine 5 mg/ml and 20 ml of lidocaine 20 mg/ml with 5 microg/ml epinephrine (total 40 ml) was administered in both groups. In the Group S following a median, an ulnar or a radial nerve response, the entire LA was administered at a single site. In Group D 10 ml of LA was administered following the electrolocation of the musculocutaneous nerve and 30 ml LA was injected following median, ulnar or radial nerves. A successful block was defined as analgesia or anesthesia of all five nerves distal to the elbow. Sensory and motor blocks were tested at 5-min intervals for 30 min.

RESULTS

The block was successful in 27 patients in Group S and 28 patients in Group D. The time from starting the block until satisfactory anesthesia was significantly shorter in Group D than in Group S (19.3 vs. 23.2 min) (P<0.05). Total sensory scores were significantly higher in the double stimulation group at 20 and 30 min after the block performance (P<0.05).

CONCLUSIONS

Although the block performance time was longer in the double stimulation group, block onset time and extent of anesthesia were more favorable in the double stimulation group.

[Treatment of mid-distal humeral shaft fractures associated with radial nerve palsy using minimally invasive plating osteosynthesis technique]

OBJECTIVE

To explore the possibility of treating mid-distal humeral shaft fractures associated with radial nerve palsies with minimal invasive plating osteosynthesis (MIPO) techniques.

METHODS

From April 2003 to October 2006, 10 patients with mid-distal humeral shaft fractures associated with radial nerve palsies were treated. All patients were male, aged 19-58 years. According to AO/ASIF classification, there were 4 cases of B1 type, 2 cases of B3 type, 1 case of A2 type, 1 case of B2 type, 1 case of C3 type and 1 case of A3 type. A straight 4.5 mm dynamic compression plate was placed on the anterior aspect of humerus through two small incisions located on the anterior side of proximal and distal part of the arm. The radial nerve exploration was performed through a lateral small incision made on the fracture site. The fractures were then reduced by manual manipulation and the plate was fixated to the main fragments with 3 screws in each end of the plate. The postoperative complications, the bone healing time, and the recovery time of the radial nerve functions were recorded. The functions of the affected shoulder and elbow were assessed with UCLA and Mayo elbow performance score system respectively.

RESULTS

All incision healed by first intention. Ten patients were followed up 9-36 months with an average of 15.7 months. The X-ray films showed that the union of fractures was achieved 12-16 weeks (13.6 weeks on average). The function of the radial nerves recovered completely 12-36 weeks (17.8 weeks on average) in 9 patients. The abductions of the affected shoulder were 150-170 degrees (165 degrees on average). The ROM of the elbows were 130-140 degrees (135.5 degrees on average). According to the UCLA shoulder scoring system, 9 patients achieved the excellent result and 1 patient achieved the good result. All the patients had the excellent results according to Mayo elbow performance score system.

CONCLUSION

The mid-distal humeral shaft fractures associated with radial nerve palsies can be treated with MIPO technique and the good results can be obtained.

[Radial nerve compression syndrome at the elbow with reference to radiohumeral epicondylosis--clinico-anatomic studies]

Compression of the radial nerve in the angle of the elbow can manifest itself clinically as "epicondylosis" ("tennis elbow"). Operative findings and systematic necropsy studies point to four specific areas in which a compression of the radial nerve occurs: 1. Occasionally, firm connective tissue fibers running between the brachialis and brachioradialis extend over the radial nerve in the proximal part of the radial tunnel. 2. Blood vessels may cross the nerve in the angle of the elbow and cause compression. 3. The profundus branch of the nerve may be compressed by the tendon of the extensor carpi radialis brevis when the origin of the muscle is located far medially, and 4. by the tendon of the superficial part of the supinator (arcade of Frohse). These structures can lead to an entrapment neuropathy of the radial nerve, and thereby to an epicondylosis humeri radialis. In patients with clinical symptoms of "epicondylitis" feeling pain along the radial nerve upon application of pressure, the nerve should be exposed to that compressing structures may possibly be released operatively.

Median and radial nerve compression about the elbow

It is important for physicians who treat upper extremity disorders to understand motor palsy or pain syndromes caused by compression of the median and radial nerves about the elbow and forearm. Patients with anterior interosseous nerve syndrome may report hand weakness, whereas those with pronator syndrome may present with pain and paresthesia that can be confused with carpal tunnel syndrome. Patients with posterior interosseous nerve syndrome report hand weakness, whereas those with radial tunnel syndrome report pain in the lateral elbow and forearm, which may be confused with lateral epicondylitis. Because each syndrome has overlapping symptoms, serial examinations are needed to determine the correct diagnosis.

The effects of medetomidine on radial nerve blockade with mepivacaine in dogs

OBJECTIVE

To compare the sensory and motor effects of adding medetomidine to mepivicaine, administered either perineurally or systemically, for radial nerve block in dogs.

STUDY DESIGN

Prospective randomized cross-over study.

ANIMALS

Six healthy Beagles, aged 18.7 +/- 6.3 months and weighing 10.4 +/- 1.3 kg.

METHODS

Dogs were anesthetized briefly with sevoflurane on three separate occasions and received each treatment administered in random order: mepivacaine 5 mg kg(-1) perineurally around the radial nerve with saline 0.01 mL kg(-1) intramuscularly (CONTROL); mepivacaine 5 mg kg(-1) and medetomidine 0.01 mg kg(-1) combined, perineurally with saline 0.01 mL kg(-1) intramuscularly (MEDPN); mepivacaine 5 mg kg(-1) perineurally around the radial nerve with medetomidine 0.01 mg kg(-1) intramuscularly (MEDIM). All nerve blocks were performed with the aid of a nerve locator. Motor effects were evaluated based on the ability to bear weight. Sensory effects were evaluated by the response to a graded-electrical stimulus. These were evaluated at 5-minute intervals for the first hour, and at 10-minute intervals thereafter. Mean intervals were calculated as follows: time to motor block onset, duration of motor block, time to peak sensory block, duration of peak sensory block (i.e. period of no response to maximal stimulus intensity), and duration of residual sensory block (i.e. time to return to baseline sensory function). Treatment means were compared using a one-way analysis of variance for repeated measures and, where significant differences were noted, a Student-Newman-Keuls test was applied; p < 0.05 was considered significant.

RESULTS

Medetomidine, administered either systemically or perineurally, significantly prolonged duration of peak motor block, peak sensory block, and residual sensory block compared with CONTROL.

CONCLUSION

Medetomidine prolonged sensory and motor blockade after radial nerve block with mepivacaine in dogs.

CLINICAL RELEVANCE

Medetomidine may prove to be a useful adjunct to peripheral nerve blockade with local anesthetics.

[A possible cause of misdiagnosis in tumors of the axilla: schwannoma of the brachial plexus]

The Authors report a rare case of a 57 years old man affected by a left radial nerve schwannoma that occurred as an asymptomatic lesion of the axilla. At clinical examination the lump was undistinguishable from the most common axillary lymphadenopathy. A lymphoadenopathy was erroneously diagnosed with ultrasonography (US). This mistake was due to the low specificity of the instrumental methodology and to the rarity of an asymptomatic schwannoma of the infraclavicular brachial plexus. The neoplasia was excised without using the microscope. In the early post-operative follow up, a "falling" attitude of the wrist, the hand and the fingers appeared, peculiar for a lesion of the radial nerve. Furthermore a hypoaesthesia of the skin of first finger and of the first interosseus space was associated. The sensitive and motor electromyography showed a radial nerve suffering. The "stupor" of the nerve trunk was treated with steroid therapy for 7 days and the patient underwent to some series of neuro-rehabilitative physical therapy for 12 weeks. The postoperative total body CT, showed that the lesion was unique: therefore it was possible to exclude the diagnosis of neurofibromatosis. After 28 months electromyography and axillary US were performed showing the complete resolution of the motor and sensitive deficit and the absence of local recurrence.

Colocalized cellular schwannoma and plexiform neurofibroma in the absence of neurofibromatosis. Case report

The authors report on a patient without neurofibromatosis Type 1 or 2 (NF1 or NF2) and without evidence of schwannomatosis, who was found to have an unusual combination of nerve sheath tumors-a large cellular schwannoma and multifascicular involvement of a plexiform neurofibroma arising from the same site within the radial nerve and posterior cord of the infraclavicular brachial plexus. This case broadens the spectrum of combined pathological features of nerve sheath tumors. Genetic studies revealed a combined loss of neurofibromin and merlin in both regions and chromosome arm 22q deletion within the neurofibroma component only. The latter finding supports the suggestion that these were two different clonal neoplasms, and is consistent with a collision tumor pattern.

Endoscopic extracapsular capsulectomy of the elbow: a neurovascularly safe technique for high-grade contractures

Arthroscopic management of elbow contractures is rapidly becoming the primary operative form of treatment for many physicians. Safety concerns remain the primary limiting factor in its more widespread use. We use an extra-articular starting point in extremely difficult fixed contractures, and this technique is documented in this report. The ulnar nerve is initially identified and protected with a palpating finger, while a periosteal elevator is introduced through a proximal medial skin portal. A channel between the anterior humeral cortex and anterior musculature is created, and an arthroscope is introduced through a proximal lateral portal at the lateral aspect of the channel. The anterior capsule is dissected from the musculature/neurovasculature under direct vision and safely excised once the medial and lateral margins are safely identified. A useful technical tip is that retractors can be placed in auxiliary portals to deflect the muscles and fat pad to improve the ability to perform dissection under direct vision.

Increase of the heat pain threshold during and after high-frequency transcutaneous peripheral nerve stimulation in a group of normal subjects

AIM

Transcutaneous electrical nerve stimulation (TENS) is used worldwide for pain relief, but its mechanisms of action are not completely understood. High frequency transcutaneous peripheral nerve stimulation (HF-TPNS) is a term describing a type of TENS where a peripheral nerve is stimulated transcutaneously. The aim of the investigation was to verify the hypothesis that HF-TPNS increases the heat pain threshold in the skin territory of the stimulated nerve, during and after stimulation.

METHODS

Eighteen volunteers (8 men, 10 women) participated in 2 sessions conducted on different days. In each session their heat pain thresholds were measured in basal conditions and after 5, 10, 15, 25, 40, 70 min. In one session, HF-TPNS was delivered for 10 min immediately after basal evaluation (HF-TPNS session). In the other session the heat pain thresholds only were measured (control session). The superficial radial nerve was stimulated at the wrist (frequency of 100 Hz, pulse duration of 0.1 ms). The heat pain threshold was studied using a contact thermode (surface of 12.5 cm(2)) placed in the cutaneous area of the stimulated nerve at the site where the paresthesia evoked by electrical stimulation could be felt.

RESULTS

HF-TPNS significantly increased the heat pain threshold both during and after stimulation.

CONCLUSION

This study confirms that HF-TPNS induces an important hypoalgesic effect. The prolonged duration of poststimulation hypoalgesia (60 min) indicates that continuous stimulation is probably unnecessary. Further studies are needed to test the hypothesis that intermittent HF-TPNS is able to maintain its hypoalgesic effectiveness over time.

Feasibility of Forearm Ultrasonography-Guided Nerve Blocks of the Radial, Ulnar, and Median Nerves for Hand Procedures in the Emergency Department

STUDY OBJECTIVE

We determine the feasibility of forearm ultrasonography-guided nerve blocks of the radial, ulnar, and median nerves, performed by emergency physicians, to provide procedural anesthesia of the hand in the emergency department (ED).

METHODS

This was a prospective study involving a convenience sample of 11 patients presenting to an adult ED with hand pathology requiring a procedural intervention. Adults 18 years and older who presented to the ED during the 3-month study period were eligible. Physicians performing the nerve blocks were attending physicians, ultrasonography fellows, or residents who had participated in a 1-hour training session. The participants underwent ultrasonography-guided nerve blocks in the forearm to provide anesthesia. Any additional anesthesia or analgesia required to perform the procedure in the anesthetized region was recorded. Subjects rated their pain on a 100mm visual analog scale before the nerve block and 15 minutes after the nerve block. The primary outcomes for feasibility were the percentage of cases completed without rescue anesthesia or analgesia and the median reduction in pain on the visual analog scale after the nerve block. Secondary outcomes for feasibility included the median time to completion of the entire nerve block procedure for each subject (from initiation of ultrasonography to completion of the last injection) and the percentage of participants wishing to have the same procedure for similar injuries in the future. Other secondary outcomes included the percentage of participants with complications during the procedure and at 3 months.

RESULTS

All procedures (100%) were completed without additional anesthesia or analgesia. The median reduction in visual analog scale score was 5.0 cm (interquartile range 3.0, 8.0; P=.003). The median time to completion of nerve blocks was 9 minutes per patient (interquartile range 6 minutes 30 seconds, 10 minutes 0 seconds), with a median of 2 blocks per patient. Ten of 11 patients (92%) stated they would wish to have the ultrasonography-guided nerve block in the future for similar injuries. There were no immediate complications and no complications reported at 3 months.

CONCLUSION

Attending physicians, fellows, and residents can perform forearm ultrasonography-guided nerve blocks of the radial, ulnar, and median nerves quickly, without additional anesthesia and with high patient satisfaction, after minimal training. Although pilot data are suggestive, randomized controlled trials are needed to determine efficacy and safety. Ultrasonography-guided nerve blocks to provide anesthesia for hand procedures appear to be feasible in the ED.

Superficial radial nerve compression caused by a parosteal lipoma of proximal radius: a case report

The superficial radial nerve might be compressed or injured at various anatomical sites along its course in the forearm. Most of the superficial radial nerve neuropathy are caused by pathological lesions such as trauma, a mass or tight band at the distal third of the forearm. Wartenberg's syndrome is the most common cause of sensory radial entrapment at the distal forearm. Compression of superficial radial nerve occurring at the proximal third of forearm is unusual. We present a rare case of superficial radial nerve compression due to a parosteal lipoma of proximal radius. Results of complete physical and radiological examinations are also presented. Surgical intervention of the tumour mass was performed for nerve decompression. The patient reported total relief of the neurological symptom post-operatively. This rare case demonstrates the unique characteristics of parosteal lipoma with unusual superficial radial nerve neuropathy at the proximal radius. This report reminds us that there is the possibility of superficial nerve compression caused by tumour mass over the proximal third of forearm.

Neuro-physiological study in persons with cervico-brachial disorders

OBJECTIVES

In order to clarify the involvement in the nervous system by cervico-brachial disorders (CBD), we performed neurophysiological tests on the peripheral nervous system (PNS) and the central nervous system (CNS) in patients with CBD, subclinicals and healthy controls.

SUBJECTS AND METHODS

We employed antidromic sensory nerve conduction velocities (SCV) in the hands and fingers for PNS function and event-related potentials (P300) for CNS higher function. Subjects for SCV were 27 patients, 14 workers with sign and symptoms of CBD (subclinicals) and 22 controls. Subjects for P300 were 23 patients, 12 subclinicals and 10 healthy controls.

CONCLUSIONS

In the PNS, since significant reduction SCV in the index finger among patients was observed, we could not find clear evidence of decrease of conduction function. In the CNS, since the latencies and amplitudes of auditory P300 among patients were significantly delayed and decreased, respectively, and the latencies significantly correlated with symptom score, it was suggested that the dysfunction of the cognition and memory function. However, further investigation is necessary to clarify the mechanism.

[Posterior interosseous nerve palsy in a man in a lateral position for laparoscopic adrenalectomy--a case report]

A 51-year-old man with aldosteronism underwent laparoscopic left adrenalectomy. Anesthesia was induced with fentanyl 0.1 mg, propofol 140 mg and vecuronium 7 mg. Following endotracheal intubation, he was placed in a right lateral position with extension of his left side, and fixed with the Magic Bed. Canulation of the right radial artery was smoothly performed. Anesthesia was maintained with sevoflurane and thoracic epidural anesthesia (mepivacaine and ropivacaine). The operation lasted for 270 minutes and was uneventful. A few hours after surgery, he complained of inability to extend his right fingers without any sensory loss, and the local oppressive pain on his right forearm. Neurological examination revealed a posterior interosseous palsy. Symptoms improved gradually and disappeared completely in two months with the administration of vitamin B12 and physical therapy. Postoperative reproduction of the positioning of this case disclosed that the edge of the Magic Bed might potentially compress the posterior interosseous nerve at the point where the nerve is bifurcated from the radial nerve and travels within the supinator muscle going into the muscle again. This case indicated that we must be careful of nerve injuries due to devices used to maintain the patient in lateral position.

[Entrapment neuropathies of the arm]

Compression-induced damage to the peripheral nerves can cause persistent, mostly exercise-related intensified pain syndromes. In the presence of brachialgia, compression neuropathies must always be considered when rendering the differential diagnosis, whether in the scapular region (e.g. suprascapular syndrome) in the elbow (e.g. supinator syndrome) or the hand (carpal tunnel syndrome, distal ulnar tunnel syndrome). Knowledge of neuroanatomy, detailed history of pain and provocative movements and a targeted examination technique including the findings of provocative testing will usually lead to an accurate diagnosis. Focal neural damage, its exact localization and degree of severity can all be confirmed by the targeted use of electroneurography and needle myography. These procedures will also allow a prognostic estimation and provide information about whether surgical therapeutic procedures are indicated.