Long-standing Nonunited Fracture Lateral Humeral Condyle in Children. Evaluating a Two-stage Surgical Treatment Strategy With Critical Review

OBJECTIVE

This work aimed to evaluate the results of using a 2-stage surgical treatment strategy without doing anterior transposition of the ulnar nerve (ATUN) for cases with long-standing nonunited fracture lateral humeral condyle (LHC) in children, accompanied by a critical review.

METHODS

A consecutive 12 children with a long-standing ">2 years" nonunited LHC with evident radiologic gross anatomic distortion of the elbow were included in this study. A 2-stage surgical treatment strategy was applied, wherein the first stage, open functional reduction, osteosynthesis, and iliac bone graft were done. Then after 6 months, the second stage surgery was carried out in the form of supracondylar humeral corrective osteotomy if the cubitus valgus angle was ≥20 degrees. ATUN was not done for any of the cases even with those having ulnar nerve dysfunction.

RESULTS

Union took place in 11 out of the 12 cases after a mean follow-up period of 11 weeks (range: 8 to 14 wk; SD: 1.6). All the 7 cases showed preoperative ulnar nerve dysfunction and reported clinical recovery at the end of their follow-up.

CONCLUSIONS

Two-stage surgical treatment strategy without ATUN is a convenient, reproducible, and successful line of treatment for children presented with longstanding nonunited LHC with anatomically distorted elbow.

LEVEL OF EVIDENCE

Level IV-case series.

Nerve Transfer After Cervical Spinal Cord Injury: Who Has a "Time Sensitive" Injury Based on Electrodiagnostic Findings?

OBJECTIVE

To use the ulnar compound muscle action potential (CMAP) to abductor digiti minimi (ADM) to identify the proportion of individuals with cervical spinal cord injury (SCI) who have lower motor neuron (LMN) abnormalities involving the C8-T1 spinal nerve roots, within 3-6 months, and thus may influence the response to nerve transfer surgery.

DESIGN

Retrospective analysis of prospectively collected data. Data were analyzed from European Multicenter Study About SCI database.

SETTING

Multi-center, academic hospitals.

PARTICIPANTS

We included 79 subjects (age=41.4±17.7, range:16-75; 59 men; N=79), who were classified as cervical level injuries 2 weeks after injury and who had manual muscle strength examinations that would warrant consideration for nerve transfer (C5≥4, C8<3).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The ulnar nerve CMAP amplitude to ADM was used as a proxy measure for C8-T1 spinal segment health. CMAP amplitude was stratified into very abnormal (<1.0 mV), sub-normal (1.0-5.9 mV), and normal (>6.0 mV). Analysis took place at 3 (n=148 limbs) and 6 months (n=145 limbs).

RESULTS

At 3- and 6-month post-injury, 33.1% and 28.3% of limbs had very abnormal CMAP amplitudes, respectively, while in 54.1% and 51.7%, CMAPs were sub-normal. Median change in amplitude from 3 to 6 months was 0.0 mV for very abnormal and 1.0 mV for subnormal groups. A 3-month ulnar CMAP <1 mV had a positive predictive value of 0.73 (95% CI 0.69-0.76) and 0.78 (95% CI 0.75-0.80) for C8 and T1 muscle strength of 0 vs 1 or 2.

CONCLUSION

A high proportion of individuals have ulnar CMAPs below the lower limit of normal 3- and 6-month post cervical SCI and may also have intercurrent LMN injury. Failure to identify individuals with LMN denervation could result in a lost opportunity to improve hand function through timely nerve transfer surgeries.

Prevalence of bilateral ulnar nerve subluxation among professional baseball pitchers

BACKGROUND

Radiographic and physical examination findings of ulnar nerve instability have been recognized in overhead throwing athletes, despite the fact that some of these abnormalities may be asymptomatic and represent adaptive changes. While recommendations for screening and early detection have been made that can adversely impact an athletes' career, the presence of bilateral ulnar nerve subluxation and its relationship with medial elbow symptoms has not been characterized in professional overhead throwing athletes.

PURPOSE

To characterize the prevalence of bilateral ulnar nerve subluxation among professional baseball pitchers.

METHODS

A cross-sectional observational analysis was conducted utilizing standardized ultrasonographic examinations of bilateral elbows in 91 consecutive professional baseball pitchers (median age, 22 years; range, 17-30 years). The relationship between ulnar nerve subluxation and ulnar nerve signs, symptoms, and provocative physical examination maneuvers was also investigated.

RESULTS

The prevalence of bilateral ulnar nerve subluxation was 26.4% (95% CI, 17.7%-36.7%; 24 of the 91 athletes). Thirty-five athletes (38.5%; 95% CI, 28.4%-49.2%) had subluxation in at least 1 elbow. No athletes with subluxation had positive ulnar nerve signs, symptoms, or provocative tests.

CONCLUSION

Ulnar nerve subluxation is common among professional pitchers, and is more often than not bilateral. In this population of athletes, ulnar nerve subluxation does not appear to be associated with pathological findings.

Comparison of electrodiagnostic findings in acute traumatic versus chronic non-traumatic ulnar neuropathy at the elbow

INTRODUCTION/AIMS

A common concept is that traumatic nerve injuries are more likely axonal, and that compressive neuropathies are more likely demyelinating. The purpose of this study was to compare traumatic versus non-traumatic ulnar neuropathy at the elbow (UNE) to look for electrodiagnostic differences between the two groups.

METHODS

A retrospective 3 year review of UNE patients at two academic health science centers was conducted. Patients were grouped into acute traumatic UNE versus chronic non-traumatic UNE based on clinical history. Electrodiagnostic measurements were compared between the two groups.

RESULTS

There were 50 subjects with acute traumatic UNE and 41 with chronic non-traumatic UNE. Mean age and sex distribution were similar but those with traumatic UNE had a 7 month duration of symptoms, while those with chronic UNE had 29 month duration (p < .001). All electrodiagnostic measurements were similar between the two groups including compound muscle action potential amplitudes, motor conduction velocities, frequency of conduction block, sensory nerve studies, and needle electromyography.

DISCUSSION

We did not find a difference between the two groups. One should not make inferences regarding acuity or etiology based on electrodiagnostic features alone.

Supracondylar Humerus Fractures: When Lateral Entry Pins Are Not Enough

Percutaneous pin configuration for the management of pediatric supracondylar humerus fractures has been studied extensively both in the biomechanics laboratory and in the clinical setting. Medial entry pins (ie, crossed pinning) increase supracondylar humerus fracture construct stability under certain loading conditions. However, there are noted drawbacks of medial entry pinning, specifically the risk of iatrogenic ulnar nerve injury. In most circumstances, the additional biomechanical stability of crossed pinning is unlikely to be clinically necessary for maintenance of fracture alignment, but there are scenarios in which medial entry pins should be strongly considered. It is important to review the biomechanics of various pin configurations in the setting of pediatric supracondylar humerus fractures, discuss the indications for medial entry pinning (crossed pinning), and discuss a safe technique for applying medial entry pins when indicated.

Force loss and distribution of load in the hands of patients with cubital tunnel syndrome

Manugraphy with three different cylinder sizes was used to quantify the contribution of fingers, thumb and palm to grip force in patients with unilateral cubital tunnel syndrome. Forces in the affected and contralateral hands differed by up to 29%. Although grip force is usually maximal when gripping small handles, ulnar nerve palsy resulted in similar absolute grip forces using the 100-mm and 200-mm cylinders. The contact area between the affected hand and the cylinders was reduced by 5%-9%. We noted a high correlation between the contact area and grip force, visible atrophy and permanently impaired sensibility. The load distribution differed significantly between both hands for all cylinder sizes. When gripping large objects, the main functional impairment in cubital tunnel syndrome is weakness in positioning and stabilizing the thumb. Weak intrinsic finger muscles are responsible for loss of force when gripping small objects. Level of evidence: III.

Effects of the attachment method of the stimulating electrodes Nihon-Kohden NM-345Y™ and changes in forearm position on stimulus current values during calibration in electromyography-based neuromuscular monitoring: a single-center experimental study

PURPOSE

The traditionally recommended method for attaching electromyography (EMG) electrodes (NM-345Y™) during EMG-based neuromuscular monitoring developed by Nihon-Kohden may decrease the monitoring accuracy when forearm limb position changes. This study investigated methods for attaching stimulating electrodes that maintained stable EMG-based neuromuscular monitoring accuracy, regardless of forearm limb position changes.

METHODS

This single-center experimental study recruited 28 healthy adults from October 2022 to December 2022. The NM-345Y™ was attached to the forearm using three patterns: Pattern N, electrodes attached according to the attachment pattern recommended by Nihon-Kohden; Pattern U, electrodes attached along the ulnar nerve identified using an ultrasound device; Pattern C, electrodes attached where the ulnar nerve crosses the line connecting the centers of the anode and cathode of the stimulating electrodes. The stimulus current values during calibration were measured at three forearm positions for each attachment pattern: supination 90 degrees; pronation 0 degrees; pronation 90 degrees. The differences in stimulus current values caused by forearm position changes were calculated as the difference between values at supination 90 degrees and pronation 0 degrees and between values at supination 90 degrees and pronation 90 degrees.

RESULTS

Pattern C showed significantly smaller differences than Pattern N between the stimulus current values at supination 90 degrees and pronation 0 degrees (p = 0.018) and between the stimulus current values at supination 90 degrees and pronation 90 degrees (p = 0.008).

CONCLUSION

Crossing the ulnar nerve with the line connecting the anode and cathode of the stimulating electrodes may stabilize EMG-based neuromuscular monitoring accuracy.

Axonal mapping of motor and sensory components within the ulnar nerve and its branches

OBJECTIVE

Intrinsic function is indispensable for dexterous hand movements. Distal ulnar nerve defects can result in intrinsic muscle dysfunction and sensory deficits. Although the ulnar nerve's fascicular anatomy has been extensively studied, quantitative and topographic data on motor axons traveling within this nerve remain elusive.

METHODS

The ulnar nerves of 14 heart-beating organ donors were evaluated. The motor branches to the flexor carpi ulnaris (FCU) and flexor digitorum profundus (FDP) muscles and the dorsal branch (DoBUN) as well as 3 segments of the ulnar nerve were harvested in 2-cm increments. Samples were subjected to double immunofluorescence staining using antibodies against choline acetyltransferase and neurofilament.

RESULTS

Samples revealed more than 25,000 axons in the ulnar nerve at the forearm level, with a motor axon proportion of only 5%. The superficial and DoBUN showed high axon numbers of more than 21,000 and 9300, respectively. The axonal mapping of more than 1300 motor axons revealed an increasing motor/sensory ratio from the proximal ulnar nerve (1:20) to the deep branch of the ulnar nerve (1:7). The motor branches (FDP and FCU) showed that sensory axons outnumber motor axons by a ratio of 10:1.

CONCLUSIONS

Knowledge of the detailed axonal architecture of the motor and sensory components of the human ulnar nerve is of the utmost importance for surgeons considering fascicular grafting or nerve transfer surgery. The low number of efferent axons in motor branches of the ulnar nerve and their distinct topographical distribution along the distal course of the nerve is indispensable information for modern nerve surgery.

Ulnar nerve neuropathy caused by pathologic ossification: a case report

PURPOSE

Cubital tunnel syndrome is a well-described entity with many reported etiologies and anatomical compression sites. Accessory ossicles of either traumatic or congenital origin might occur around the elbow joint. Only one case reporting such ossicles compressing the ulnar nerve exists in previous literature. We aim to present this entity with a detailed description of the patient history and treatment.

CASE REPORT

We report a case of 30-year-old female presenting with classical signs of cubital tunnel syndrome-positive Wartenberg's and Froment's signs, hypoesthesia in the fourth and fifth finger with decreased finger duction strength but without gross hypotrophy of interosseous and hypothenar muscles. Tinel's sign was positive over the ulnar sulcus and an accessory ossicle was found on the elbow radiograph within the ulnar sulcus. The first signs of calcification in this patient were reported 6 years prior in a follow-up after the dislocation of her elbow joint following a bike accident. The EMG confirmed ulnar nerve neuropathy in the elbow area. The ossicle was extirpated, the ulnar nerve was decompressed in the ulnar sulcus in a standard manner and the symptoms quickly resolved. The patient has been regularly visiting our outpatient clinic for the next 12 years without any complaints considering her elbow and the ulnar nerve.

CONCLUSION

This is a rare case of cubital tunnel syndrome caused by an accessory ossicle of traumatic origin. Simple bone extirpation with ulnar nerve release followed by anterior subcutaneous transposition is the recommended method of treatment. No report of congenital accessory bones causing ulnar nerve compression in the elbow exists in the literature.

Modified paratricipital approach without mobilization of the ulnar nerve prevents postoperative ulnar neuropathy in distal humerus fractures

BACKGROUND

In distal humerus fracture surgery, postoperative ulnar neuropathy is a common complication. The present study assessed the utility of the modified paratricipital approach for preventing ulnar neuropathy. This approach preserved the continuity of the attachment of the triceps with the ulnar nerve and allowed anterior subluxation of the ulnar nerve onto the hardware to be avoided.

METHODS

From December 2018 to March 2020, 13 patients who underwent surgery for distal humerus fracture through the modified paratricipital approach at our hospital were prospectively enrolled in the study. Ulnar neuropathy, Mayo Elbow Performance Score (MEPS), and Range of motion (ROM) were evaluated.

RESULTS

No postoperative ulnar neuropathy was observed. At the final follow-up, the mean Mayo Elbow Performance score was 97.7 (range, 85-100). The mean arc motion was 132.7° (range, 115°-145°) with a mean flexion contracture of 4.2° (range, 0°-10°) and mean flexion of 136.2° (range, 120°-145°). Hardware breakage leading to a loss of reduction occurred in one case, but the other fractures united.

CONCLUSIONS

Our results demonstrated the effectiveness of the modified paratricipital approach for preventing postoperative ulnar neuropathy. The modified paratricipital approach is a safe and reliable method of performing distal humerus fracture surgery.

Effect of Forearm and Elbow Joint Positions on Ulnar Nerve Conduction Velocity: A Study of Throwers, Archers, and Non-Athletes

Background: The intensive physical regimen followed by throwers and archers can impose stress on the elbow and hand in particular positions, which may increase the risk of developing peripheral nerve disorders and symptoms like pain and numbness. Purpose: The purpose of the study is to investigate the effect of forearm and elbow joint positions on ulnar nerve conduction velocity in throwers, archers, and non-athletes. Method: Total 34 subjects both males and females were included with body mass index (BMI) between 18.5 and 24.9 kg/m2. Nerve conduction study (NeuroStim NS2 EMG/NCV/EP System) was used for measuring ulnar nerve conduction velocity (NCV) across elbow joint at different angles (0° elbow extension, 45°, 90°, and 120° elbow flexion) with different forearm positions. Result: Repeated Measure Analysis of Variance (RMANOVA) revealed that there was a statistically significant difference in mean values of ulnar NCV at different angles, forearm positions & groups (p < .05). Conclusion: The forearm and elbow positions can have a significant impact on ulnar NCV, especially in athletes who perform repetitive upper limb motions. Results showed that the archers had significantly slower NCV than throwers and non-athletes at 90° of elbow flexion and forearm pronation.

Median artery persistence in coexistence with a bifid median nerve and interconnections of the median with the ulnar nerve and vice versa

PURPOSE

This report describes a bilateral persistent median artery (PMA) originating from the ulnar artery and terminating at different levels of the upper limb. The PMA coexisted with a bilateral bifid median nerve (MN) and two bilateral interconnections (ICs characterized with the symbol -) of the MN with the ulnar nerve (UN) (MN-UN) and a unilateral reverse IC (UN-MN). Emphasis was given to the artery's developmental background.

METHODS

The PMA was identified in an 80-year-old formalin-embalmed donated male cadaver.

RESULTS

The right-sided PMA terminated at the wrist, posterior to the palmar aponeurosis. Two neural ICs were identified: the UN joined the MN deep branch (UN-MN), at the forearm's upper third, and the MN deep stem joined the UN palmar branch (MN-UN), at the lower third (9.7 cm distally to the 1st IC). The left-sided PMA ended in the palm giving off the 3rd and 4th proper palmar digital arteries. An incomplete superficial palmar arch was identified by the contribution of the PMA, radial, and ulnar arteries. After the MN bifurcation into superficial and deep branches, the deep branches formed a loop, that was penetrated by the PMA. The MN deep branch communicated with the UN palmar branch (MN-UN).

CONCLUSIONS

The PMA should be evaluated as a causative factor of carpal tunnel syndrome. The modified Allen's test and the Doppler ultrasound may detect the arterial flow and the angiography may depict the vessel thrombosis in complex cases. PMA could also be a "salvage" vessel for the hand supply, in radial and ulnar artery trauma.

Ultrasonographic examination of the safe zone for medial needle approach towards the median-innervated flexor digitorum profundus muscle: Effect of changes in position of the forearm

The flexor digitorum profundus (FDP) is a forearm flexor muscle. Certain cases require the needle to be inserted accurately and safely into the deep, lateral portion of the FDP, which is innervated by the anterior interosseous nerve. In this study, we compared 2 techniques for approaching the median-innervated FDP (MFDP) medially, each according to the position of the forearm, supinated or pronated. The forearms of healthy volunteers without any musculoskeletal problems of the upper extremities were examined. Using high-resolution ultrasonography, the medial aspects of the forearms were scanned with elbows flexed at 90°. Using the images obtained, several parameters for distance and angle were measured in 2 different positions: forearm-supinated and forearm-pronated. Thirty-seven forearms from the volunteers were subject to examination. The angle α, which is the valid angle of insertion when approaching with the needle towards the deeply located MFDP, slightly increased from 22.89° to 23.41° when the forearm was pronated from the supinated position; however, this increase was not statistically significant. In contrast, the angle β, which is the safe angle of insertion when approaching with the needle towards the MFDP without contacting the ulnar nerve, was significantly increased from 41.40° to 46.80° upon forearm pronation. Because the safe angle of insertion of the needle medially into the MFDP increases with forearm pronation, the forearm-pronated position is recommended, instead of the forearm-supinated position, when inserting a needle into the MFDP in the medial aspect of the forearm.

Ultrasound Scanning Protocol in the Assessment of Ulnar Neuropathy at the Elbow

Ulnar neuropathy at the elbow is commonly encountered in clinical practice and is the second most common entrapment neuropathy. Left untreated, ulnar neuropathy at the elbow can result in significant disability due to loss of dexterity and grip strength secondary to the weakness of intrinsic hand muscles. Precisely localizing a lesion in ulnar neuropathy can be challenging with electrodiagnostic testing alone. Ultrasound is a relatively quick and useful adjunctive diagnostic modality in overcoming this limitation, as an increase in the cross-sectional area (CSA) of the nerve is a common and validated finding in ulnar neuropathies at the elbow. Sonographic assessment of the nerve's echotexture and vascularity can provide additional diagnostic clues. Ultrasound also offers the unique benefit of detecting ulnar nerve subluxation or dislocation out of the retroepicondylar groove during dynamic assessment, although the clinical significance of this is controversial. Finally, ultrasound can also identify structural abnormalities leading to nerve compressions, such as the presence of bony abnormalities, scar tissue, and space-occupying lesions. These findings may influence management strategies and surgical planning. This protocol aims to illustrate the technique of static and dynamic sonographic imaging of the ulnar nerve around the elbow as a complement to electrodiagnostic testing in the assessment of ulnar neuropathy at the elbow.

Sonographic peripheral nerve cross-sectional area in adults, excluding median and ulnar nerves: A systematic review and meta-analysis

INTRODUCTION/AIMS

Although electromyography remains the "gold standard" for assessing and diagnosing peripheral nerve disorders, ultrasound has emerged as a useful adjunct, providing valuable anatomic information. The objective of this study was to conduct a systematic review and meta-analysis evaluating the normative sonographic values for adult peripheral nerve cross-sectional area (CSA).

METHODS

Medline and Cochrane Library databases were systematically searched for healthy adult peripheral nerve CSA, excluding the median and ulnar nerves. Data were meta-analyzed, using a random-effects model, to calculate the mean nerve CSA and its 95% confidence interval (CI) for each nerve at a specific anatomical location (= group).

RESULTS

Thirty groups were identified and meta-analyzed, which comprised 16 from the upper extremity and 15 from the lower extremity. The tibial nerve (n = 2916 nerves) was reported most commonly, followed by the common fibular nerve (n = 2580 nerves) and the radial nerve (n = 2326 nerves). Means and 95% confidence interval (CIs) of nerve CSA for the largest number of combined nerves were: radial nerve assessed at the spiral groove (n = 1810; mean, 5.14 mm2 ; 95% CI, 4.33 to 5.96); common fibular nerve assessed at the fibular head (n = 1460; mean, 10.18 mm2 ; 95% CI, 8.91 to 11.45); and common fibular nerve assessed at the popliteal fossa (n = 1120; mean, 12.90 mm2 ; 95% CI, 9.12 to 16.68). Publication bias was suspected, but its influence on the results was minimal.

DISCUSSION

Two hundred thirty mean CSAs from 15 857 adult nerves are included in the meta-analysis. These are further categorized into 30 groups, based on anatomical location, providing a comprehensive reference for the clinician and researcher investigating adult peripheral nerve anatomy.

Using Electrical Stimulation of the Ulnar Nerve Trunk to Predict Postoperative Improvement in Hand Clumsiness in Patients With Cervical Spondylotic Myelopathy

STUDY DESIGN

A prospective cohort study.

OBJECTIVE

To investigate whether the immediate and short-term effects of preoperative electrical peripheral nerve stimulation (ePNS) on performance of the 10-second test could predict the early postoperative outcomes of patients with cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

Previous studies have shown that early clinical improvement in CSM patients may be because of reversal of spinal cord ischemia after spinal cord compression.

MATERIALS AND METHODS

We conducted a 10-second test before surgery, after ePNS, and at discharge (one week after surgery) in 44 patients with CSM who underwent C3-C7 laminoplasty and evaluated their correlations. The effects of the procedures (ePNS or operation) and sides (stimulated or nonstimulated side) for the 10-second test were analyzed using repeated measures analysis of variance. The Pearson correlation coefficient was used to measure the relationship between the 10-second test values according to the method (after ePNS vs. surgery). In addition, the Bland-Altman method was used to evaluate the degree of agreement between the 10-second test obtained after ePNS versus shortly after surgery.

RESULTS

The preoperative 10-second test showed the most improvement immediately after the administration of ePNS, with a gradual decrease for the first 30 minutes after completion. After the initial 30 minutes, performance decreased rapidly, and by 60 minutes performance essentially returned to baseline. The 10-second post-ePNS had a strong positive correlation with the 10-second test in the early postoperative period (at discharge=one week after surgery). These phenomena were observed with the left hand, the side stimulated with ePNS, as well as the right hand, the side not stimulated.

CONCLUSIONS

Early postoperative outcomes after CSM surgery may be predicted by the results of preoperative ePNS.

LEVEL OF EVIDENCE

Level 3.

Effects of weight loss after bariatric surgery on the median and ulnar nerves conduction studies

BACKGROUND

The aim of the present study was to compare the nerve conduction study (NCS) of median and ulnar nerves before and after bariatric surgery.

METHODS

This prospective cross-sectional study included 32 patients with BMI≥35 who were candidate for Sleeve gastrectomy. NCS of median and ulnar nerves were evaluated before and 3 months after surgery. In CTS cases, Boston Carpal Tunnel Questionnaire (BCTQ) was completed.

RESULTS

Eligible participants were 32 patients aged between 19 and 64 years. 20 patients including 34 hands had CTS. Severity of CTS and BCTQ scores were significantly different after surgery. Moreover, sensory amplitude, and motor NCV for both median and ulnar nerves in hands without CTS as well as sensory amplitude of ulnar nerve in hands with CTS were significantly different after bariatric surgery (P value < 0.05).

CONCLUSIONS

The results of this study suggest that three months after the bariatric surgery, the clinical and electrophysiological severity of CTS shows a significant improvement.

ETHICAL CODE OF STUDY

IR.IUMS.FMD.REC.1396.15008.

Median to ulnar nerve comparison on diagnosis of carpal tunnel syndrome in patients with diabetic polyneuropathy - A neurophysiological study

Background and purpose – To analyze the utility of median nerve (MN) to ulnar nerve (UN) comparative parameters on the diagnosis of carpal tunnel syndrome (CTS) in diabetic patients with distal symmetrical sensorimotor polyneuropathy (DSMPNP).

Methods – Patients who were referred to our electroneuromyography laboratory within the last two years were included. We compared the diagnostic accuracy values of traditional MN conduction parameters, and the MN-to-UN comparative tests on electrodiagnosis of CTS between the patients with DSMPNP involving the nerves of upper and lower extremities (UEI-positive group), and the ones without the involvement of upper extremities (UEI-negative group).

Results – There were 64 upper extremities in the UEI-positive group and 70 patients in the UEI-negative group. The most accurate traditional parameter was MN distal motor latency (DML) with a diagnostic accuracy of 70.2% whereas the most accurate comparative technique was the second lumbricalinterosseous DML difference (2L-INT DMLD) with an accuracy of 81.3%. (p=0.03). In addition, when compared diagnostic accuracy values of MN parameters with their corresponding comparative parameters in the UEI-positive group which carries the major diagnostic challenges for detecting co-morbid CTS, MN to UN minimum F wave latency (mFWL) difference, SNAP amplitude ratio on the ring finger (RF), and 2L-INT DMLD had higher accuracy values than MN mFWL, MN SNAP amplitude on RF, and MN DML on lumbrical muscle, respectively (p<0.05 for all comparisons).

Conclusion – MN to UN comparative studies have high accuracy values in electrodiagnosis of CTS in DSMPNP. In particular, 2L-INT DMLD could be helpful to overcome the diagnostic difficulty in the presence of UEI as an additional conduction technique.

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Wireless Peripheral Nerve Stimulation for The Upper Limb: A Case Report

Peripheral neuro-stimulation (PNS) has been proved to be effective for the treatment of neuropathic pain as well as other painful conditions. We discuss two approaches to PNS placement in the upper extremity. The first case describes a neuropathic syndrome after the traumatic amputation of the distal phalanx of the fifth digit secondary to a work accident with lack of responsiveness to a triple conservative therapy. An upper arm region approach for the PNS was chosen. The procedure had a favorable outcome; in fact, after one month the pain symptoms were absent (VAS 0) and the pharmacological therapy was suspended. The second case presented a patient affected by progressive CRPS type II in the sensory regions of the ulnar and median nerve in the hand, unresponsive to drug therapy. For this procedure, the PNS device was implanted in the forearm. Unfortunately, in this second case the migration of the catheter affected the effectiveness of the treatment. After examining the two cases in this paper, we changed our practice and suggest the implantation of PNS for radial, median and/or ulnar nerve stimulation in the upper arm region, which has significant advantages over the forearm region.

A portable, programmable, multichannel stimulator with high compliance voltage for noninvasive neural stimulation of motor and sensory nerves in humans

Most neural stimulators do not have a high enough compliance voltage to pass current through the skin. The few stimulators that meet the high compliance voltage necessary for transcutaneous stimulation are typically large benchtop units that are not portable, and the stimulation waveforms cannot be readily customized. To address this, we present the design and validation of a portable, programmable, multichannel, noninvasive neural stimulator that can generate three custom bipolar waveforms at ± 150 V with microsecond temporal resolution. The design is low-cost, open-source, and validated on the benchtop and with a healthy population to demonstrate its functionality for sensory and motor stimulation. Sensory stimulation included electrocutaneous stimulation targeting cutaneous mechanoreceptors at the surface of the skin and transcutaneous nerve stimulation targeting the median nerve at the wrist. Both electrocutaneous stimulation on the hand and transcutaneous stimulation at the wrist can elicit isolated tactile percepts on the hand but changes in pulse frequency are more discriminable for electrocutaneous stimulation. Also, neuromuscular electrical stimulation of the flexor digiti profundus is evoked by applying electrical stimulation directly above the muscle in the forearm and to the median and ulnar nerves in the upper arm. Muscle and nerve stimulation evoked similar grip forces and force rise times, but nerve stimulation had a significantly slower fatigue rate. The development and validation of this noninvasive stimulator and direct comparison of common sensory and motor stimulation targets in a human population constitute an important step towards more widespread use and accessibility of neural stimulation for education and research.

Correlation between nerve conduction changes and BETA-2 microglobulin concentration in chronic kidney disease patients on hemodialysis combined with hemodiafiltration online

This study aimed to investigate the correlation between beta-2 microglobulin (B2M) concentration and some nerve conduction indices and evaluate the changes in some nerve conduction indices after treatment with hemodialysis (HD) combined with hemodiafiltration online in end-stage renal disease patients. From July 2021 to July 2022, a cross-sectional study was conducted on 80 end-stage renal disease patients on HD at Can Tho General Hospital, Viet Nam. All the patients had B2M testing and nerve conduction measurements. Patients with nerve conduction disorders were treated and remeasured after 6 months to evaluate the treatment results. At baseline, there was a moderate negative correlation between B2M and the tibial nerve and motor branch of the ulnar conduction velocity (V) (r = -0.305 and -0.315, P < .05). There was a moderate positive correlation between B2M and motor latency of the tibial and peroneal nerve (r = 0.434 and 0.440, P < .05). After 6 months of using the combination of HD and hemodiafiltration online, the V (31.3 ± 7.96 up to 44.88 ± 9.67 m/s) and the amplitude (A) (1.71 ± 1.16 up to 2.61 ± 1.51 mV) of the peroneal nerve increased, the motor latency decreased (8.21 ± 2.65 down to 5.23 ± 3.58 ms). With the tibial nerve, motor conduction V increased from 30.53 ± 8.05 m/s to 43.56 ± 8.99 m/s and the A increased from 5.04 ± 3.16 mV to 7.75 ± 4.45 mV. With the ulnar nerve, the A increased, and motor latency decreased after 6 months. The nerve conduction indices also improved significantly in the median nerve.

Common peripheral nerve entrapments in the upper limb

Entrapment of peripheral nerves can occur as they travel through restrictive spaces. This nerve compression can result in a constellation of signs and symptoms, which are often called syndromes. Patients initially report pain, paraesthesia and numbness, followed by weakness and clumsiness and, ultimately, muscle wasting. The specific region of paraesthesia and pain and the specific muscle weakness is determined by the peripheral nerve involved and the location of the entrapment. Diagnosis is mainly based on history and examination. Further investigations are available for atypical presentations. Each syndrome has its own set of risk factors, but repetitive action and muscle overuse are commonly associated with most syndromes. The treatment is activity modification followed by steroid injection and finally surgical decompression for ongoing persistent symptoms or severe initial presentation. This article outlines the history, examination, possible investigations and management for common peripheral nerve entrapments of the median, ulnar and radial nerves.

[Feasibility study of protecting ulnar nerve by ultrasound in treating children with supracondylar fracture of humerus by closed reduction and intercross needle fixation]

OBJECTIVE

To explore feasibility of protecting ulnar nerve by ultrasound in treating children with supracondylar fracture of humerus by closed reduction and intercross needle fixation.

METHODS

From January 2018 to December 2019, 63 children with supracondylar fractures of humerus were divided into two groups(ultrasound group and X-ray group) depend on the different ways of guidance. Therer were 32 children in ultrasound group treated with closed reduction and Kirschner wire fixation guided by ultrasound, including 20 males and 12 females, aged from 3 to 11 years old with an average of (6.06±2.02) years old. There were 31 children in X-ray group treated with closed reduction and Kirschner wire fixation guided by X-ray, including 17 males and 14 females, aged from 2 to 10 years old with an average of (5.61±1.96) years old. Operation time, X-ray times, fracture healing time, ulnar nerve injury and postoperaqtive Flynn clinical function assessment at 1 year between two groups were recorded and compared.

RESULTS

All patients were followed up. The follow-up time of ultrasound group ranged from 9 to 12 months with an average of (11.53±0.76) months, and X-ray group ranged from 10 to 13 months with an average of (11.51±0.72) months. There was no significant difference in operation time, follow-up time and fracture healing time between two groups(P>0.05). The number of intraoperative electrodialysis in ultrasound group was (3.06±1.24) times, and that in X-ray group was (21.65±5.58) times, which was significantly higher than that in ultrasound group(P<0.01). No iatrogenic ulnar nerve injury occurred in ultrasound group, and 2 cases of ulnar nerve injury occurred in X-ray group, the incidence of ulnar nerve injury in ultrasound group was lower than that in X-ray group, but the difference was not statistically significant(P>0.05). At 1 year after operation, Flynn clinical function assessment results in ultrasound group was excellent in 27 cases, 4 cases good and 1 case fair, in X-ray group 23 cases got excellent result, 6 cases good, 1 fair and 1 poor, there was no significant difference between two groups(P>0.05 ).

CONCLUSION

Ultrasound guided and X-ray guided treatment of supracondylar fractures of humerus in children have similar effect of opertaion time and fracture healing, while ultrasound guidance could clearly detected the position of ulnar nerve, and avoid occurrence of iatrogenic ulnar nerve injury caused by ulnar puncture, which is a safe and effective treatment method.

The prevalence of the anatomical variation in a Turkish population: supernumerary muscle-anconeus epitrochlearis

INTRODUCTION

The anconeus epitrochlearis (AE) muscle is an accessory muscle located between the medial cortex of the olecranon and the inferior surface of the medial epicondyle, posterior to the ulnar nerve. This muscle may compress the ulnar nerve causing a clinical neuropathy. We aimed to determine the gender and side characteristics of the AE muscle in patients who underwent elbow magnetic resonance imaging (MRI) and report its prevalence in a Turkish population.

MATERIALS AND METHODS

A total of 209 patients (210 elbows) who underwent elbow MRI between January and December 2020 were retrospectively evaluated. Cases with the AE muscle were included in the study. The craniocaudal (CC) dimension was examined from the coronal section, and the transverse (TR) and anteroposterior (AP) dimensions from the axial sections. Statistical analyses were performed to determine the relationship between the presence of the AE muscle and age, gender, and side (right/left). Differences between sexes and sides in terms of muscle sizes were evaluated using statistical tests.

RESULTS

The AE muscle was detected in 17 patients (18 elbows) (8.1%). The mean age of the patients was 41.52 ± 14.63 years. There was no statistically significant difference between the male and female patients in terms of age. This accessory muscle was found in nine female (9.8%) and eight male (6.3%) patients in total. There was one (0.5%) patient with the bilateral AE muscle, who was female. The accessory muscle was located in the right elbow in 13 patients (10.71%), and left elbow in five (4.10%). It was more common in the right elbow in both genders. The muscle was larger in the male patients and the right elbow, but this was not statistically significant.

CONCLUSION

The prevalence of the AE muscle was determined to be 8.1% in a Turkish population, and this muscle was more common among the women and in the right elbow.

A Three months Electrodiagnostic Follow-Up of Patients Suspected of having Ulnar Nerve Involvement at Elbow Level with Normal Conventional Electrodiagnostic Study at First Evaluation

BACKGROUND

Compression of ulnar nerve at the elbow is the second most common peripheral neuropathy of the upper extremity.

OBJECTIVE

Due to the lack of the gold diagnostic standard for ulnar nerve involvement at elbow level (UNE) and the lack of sufficient study in this field, we decided to evaluate patients with symptoms of this disease who have normal conventional electrodiagnostic study (EDX) in first evaluation.

MATERIALS AND METHODS

In this cross-sectional study, 18 persons were selected from patients who were referred to the clinic of Physical Medicine and Rehabilitation. If conventional EDX was normal, compound nerve action potential (CNAP) test (peak latency and amplitude) was carried out. Patients with normal conventional EDX but abnormal ulnar CNAP included to our study. After 3 months, if they had not been treated for ulnar neuropathy, they were reexamined by conventional EDX plus ulnar CNAP measurement.

RESULTS

In total, 18 patients (11 females, 7 males) aged 28-58 years old (mean = 40.11) were analyzed in this study. After 3 months, 14 patients (77.8%) demonstrated parameter changes consistent with UNE in conventional EDX.

CONCLUSION

Based on the results of this study, ulnar CNAP has diagnostic value in patients with symptoms of UNE who have normal routine EDX. Therefore, ulnar CNAP should be taken into account for early diagnosis of ulnar neuropathy when routine electrodiagnostic tests are normal.

Comparison of Borderline Ultrasound and Nerve Conduction Studies for Carpal Tunnel Syndrome

BACKGROUND

Choosing cutoff values for nerve conduction studies (NCS) and ultrasound cross-sectional area (CSA) in the diagnosis of carpal tunnel syndrome (CTS) is critical in determining the diagnostic accuracy of the tests. The goals of this study were to: (1) determine the sensitivity and specificity of various electrodiagnostic and ultrasound threshold values for diagnosis of CTS; and (2) determine the number of hands that underwent NCS and ultrasound that were within 10% of threshold values.

METHODS

A total of 309 hands of 235 patients were included in this study. Diagnosis of median neuropathy was made based on NCS by the independent physician performing the NCS. Criteria analyzed included distal motor latency of 4.4+ ms, distal sensory latency of 3.6+ ms, difference in median-ulnar mixed nerve palmar latency of 0.4+ ms, and CSA of the median nerve of 10+ mm2.

RESULTS

Median neuropathy was diagnosed in 235 hands, whereas 74 hands were found not to have median neuropathy. Overall, 141 hands (46%) had at least 1 of the 3 electrodiagnostic variables within 10% of the diagnostic cutoff values, and 137 hands (44%) had a median nerve CSA within 10% of 10 mm2. By performing ultrasound in addition to NCS for each patient, an additional 65 hands (21%) had a definitive diagnosis on at least 1 of the 2 diagnostic modalities.

CONCLUSIONS

Ultrasound and NCS yielded a similar number of patients within 10% of their diagnostic threshold values. When used together, the number of patients with a nonborderline diagnosis on at least 1 diagnostic modality was increased substantially.

Pig Ulnar Nerve Recording with Sinusoidal and Temporal Interference Stimulation

Temporal interference stimulation has been suggested as a method to reach deep targets during transcutaneous electrical stimulation. Despite its growing use in transcutaneous stimulation therapies, the mechanism of its operation is not fully understood. Recent efforts to fill that gap have focused on computational modelling, in vitro and in vivo experiments relying on physical observations - e.g., sensation or movement. This paper expands the current range of experimental methods by demonstrating in vivo extraneural recordings from the ulnar nerve of a pig while applying temporal interference stimulation at a location targeting a distal part of the nerve. The main aim of the experiment was to compare neural activation using sinusoidal stimulation (100 Hz, 2 kHz, 4 kHz) and temporal interference stimulation (2 kHz and 4 kHz). The recordings showed a significant increase in the magnitude of stimulation artefacts at higher frequencies. While those artefacts could be removed and provided an indication of the depth of modulation, they resulted in the saturation of the amplifiers, limiting the stimulation currents and amplifier gains used. The results of the 100 Hz sine wave stimulation showed clear neural activity correlated to the stimulation waveform. However, this was not observed with temporal interference stimulation. The results suggest that, despite its greater penetration, higher currents might be required to observe a neural response with temporal interference stimulation, and more complex artefact rejection techniques may be required to validate the method.

Intra-operative application of ultrasonography combined with limited radiography for the treatment of supracondylar humerus fractures in children: a randomized controlled trial

AIMS

To introduce a new method of intra-operative application of ultrasonography (US) combined with limited radiography to treat supracondylar humerus fractures in children and evaluate its effect on radiation protection.

MATERIAL AND METHODS

 Fifty patients were randomly divided into the radiography-only group (RO group, n = 22) and the US combined with the limited radiography group (UR group, n = 28). US was performed to evaluate fracture displacement and to guide reduction in the UR group. The primary outcome measures were the average number of radiography instances and the quantitative value of radiation emission. Secondary outcome measures were length of hospital stays, loss of range of motion, loss of carrying angle, loss of Baumann angle, fracture healing time, pin site infection, compartment syndrome, cubitus varus, cubitus valgus, and iatrogenic ulnar nerve injury.

RESULTS

Average number of radiography instances and quantitative value of radiation emission in the UR group decreased compared with the RO group (p<0.05). There were no significant differences between the groups regarding mean time to surgery, the average length of hospital stays, average surgery time, radiological union time, Flynn grade, or loss of Baumann angle. Pin site infection was seen in one patient in the RO group and two patients in the UR group. No other complications occurred.

CONCLUSION

Intra-operative application of US combined with limited radiography decreases radiation exposure during treatment of supracondylar humerus fractures in children without compromising the therapeutic effect.

Entrapment of the Ulnar Nerve and Artery Associated with Closed Distal Radius and Ulna Fracture: A Case Report

CASE

We encountered a case of entrapment of the ulnar nerve and artery associated with displaced distal radius and ulna fracture. After the closed reduction, a patient noted a severe sensory deficit and had claw hand. Intraoperatively, the proximal edge of the fractured radius was positioned in the space between the ulnar artery and the nerve, and the nerve was entrapped. The entrapment was released surgically with a good 1-year outcome.

CONCLUSION

In cases of distal radius fracture, there is a possibility of entrapment of the ulnar nerve. When neurological symptoms worsen after the reduction maneuver, early nerve exploration is needed.

The Presence and Significance of A-Waves-A Retrospective Review of 679 Patients

PURPOSE

A-waves are late responses that have been reported in healthy individuals and patients with neurologic conditions. The mechanism(s) responsible for their generation and their clinical significance are not fully understood. The aim was to better characterize A-waves.

METHODS

A retrospective study was conducted in a high-volume Neurophysiology Department in a tertiary hospital in Melbourne, Australia. Consecutive neurophysiological tests including F-wave studies performed between July 2017 and September 2018 were reviewed to identify A-waves. Patients' characteristics and neurophysiological diagnoses were recorded.

RESULTS

A total of 679 patients were included in the analysis and a total of 2,730 nerves were studied. A-waves were most commonly found in tibial nerves, followed by peroneal, median, and ulnar nerves. A-waves were seen in 39.4% of individuals with otherwise normal nerve conduction studies and 39.1% of individuals with entrapment neuropathy. They were most seen in demyelinating neuropathy (85.7%), followed by mixed neuropathy (73.3%), anterior horn cell disease (66.7%), axonal neuropathy (61.2%), and radiculopathy (53.1%). Most patients with demyelinating neuropathy had multiple A-waves (61.9%), but these were also seen in 15.2% of individuals with otherwise normal nerve conduction studies and in 40% of those with other neurologic conditions. A-waves were more often seen in individuals older than 60 years.

CONCLUSIONS

A-waves are commonly seen in symptomatic individuals with otherwise normal nerve conduction studies and individuals with various neurologic conditions but are more commonly found in nerves with otherwise abnormal electrophysiological testing. A-waves are most seen in tibial nerves. Multiple A-waves were more commonly seen in demyelinating neuropathy than other conditions.

The neurophysiological lesson from the Italian CIDP database

INTRODUCTION

Electrophysiological diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) may be challenging. Thus, with the aim ofproviding some practical advice in electrophysiological approach to a patient with suspected CIDP, we analyzed electrophysiological data from 499 patients enrolled inthe Italian CIDP Database.

METHODS

We calculated the rate of each demyelinating feature, the rate of demyelinating features per nerve, the diagnostic rate for upper andlower limb nerves, and, using a ROC curve analysis, the diagnostic accuracy of each couple of nerves and each demyelinating feature, for every CIDP subtype.Moreover, we compared the electrophysiological data of definite and probable CIDP patients with those of possible and not-fulfilling CIDP patients, and by a logisticregression analysis, we estimated the odds ratio (OR) to make an electrophysiological diagnosis of definite or probable CIDP.

RESULTS

The ulnar nerve had the highestrate of demyelinating features and, when tested bilaterally, had the highest diagnostic accuracy except for DADS in which peroneal nerves were the most informative.In possible and not-fulfilling CIDP patients, a lower number of nerves and proximal temporal dispersion (TD) measurements had been performed compared to definiteand probable CIDP patients. Importantly, OR for each tested motor nerve and each TD measurement was 1.59 and 1.33, respectively.

CONCLUSION

Our findingsdemonstrated that the diagnosis of CIDP may be missed due to inadequate or incomplete electrophysiological examination or interpretation. At the same time, thesedata taken together could be useful to draw a thoughtful electrophysiological approach to patients suspected of CIDP.

Heterotopic Ossification After Revision Carpal Tunnel Release Causing Mixed Ulnar and Median Compression Neuropathy

We report a case of heterotopic ossification formation 6 years after a revision carpal tunnel release in a 46-year-old woman, causing new-onset mixed ulnar and median nerve compression symptoms. The patient underwent excision of the heterotopic ossification mass along with decompression of the median and ulnar nerves, and postoperative radiation. Four years after treatment, the patient was completely asymptomatic with full range of motion in her hand and wrist.

The Use of the Velocity Selective Recording Technique to Reveal the Excitation Properties of the Ulnar Nerve in Pigs

Decoding information from the peripheral nervous system via implantable neural interfaces remains a significant challenge, considerably limiting the advancement of neuromodulation and neuroprosthetic devices. The velocity selective recording (VSR) technique has been proposed to improve the classification of neural traffic by combining temporal and spatial information through a multi-electrode cuff (MEC). Therefore, this study investigates the feasibility of using the VSR technique to characterise fibre type based on the electrically evoked compound action potentials (eCAP) propagating along the ulnar nerve of pigs in vivo. A range of electrical stimulation parameters (amplitudes of 50 μA-10 mA and pulse durations of 100 μs, 500 μs, 1000 μs, and 5000 μs) was applied on a cutaneous and a motor branch of the ulnar nerve in nine Danish landrace pigs. Recordings were made with a 14 ring MEC and a delay-and-add algorithm was used to convert the eCAPs into the velocity domain. The results revealed two fibre populations propagating along the cutaneous branch of the ulnar nerve, with mean velocities of 55 m/s and 21 m/s, while only one dominant fibre population was found for the motor branch, with a mean velocity of 63 m/s. Because of its simplicity to provide information on the fibre selectivity and direction of propagation of nerve fibres, VSR can be implemented to advance the performance of the bidirectional control of neural prostheses and bioelectronic medicine applications.

A Provider-Focused Intervention to Promote Optimal Care of Pediatric Patients With Suspected Elbow Fracture

OBJECTIVE

Emergency department (ED) and urgent care (UC) physicians' accurate assessment of the neurovascular and musculoskeletal (NV/MSK) examination in pediatric patients with suspected elbow fracture is crucial to the early recognition of neurovascular compromise. Our objective was to determine the impact of computer-based simulation (CBS) and computerized clinical decision support systems (CCDSS) on ED and UC physicians' assessment of the NV/MSK examination of pediatric patients with elbow fracture as noted in their documentation.

METHODS

All ED UC physician participants received CBS training about management of pediatric patients with suspected elbow fracture. Participants were then randomized to receive CCDSS (intervention arm) when an eligible patient was seen or no further intervention (comparison arm.) Participants received feedback on the proportion of patients with discharge diagnosis of elbow fracturewith proper examination elements documented.

RESULTS

Twenty-eight ED and UC physicians were enrolled - 14 in each arm. Over the span of 16 weeks, 50 patients with a discharge diagnosis of elbow fracture were seen - 25 in each arm. Twenty-two of 25 (88%) patients seen by intervention arm participants had a complete NV/MSK examination documented. Six of 25 (24%) patients seen by comparison arm participants had a complete NV/MSK examination documented. Elements most commonly missed in the comparison arm included documentation of ulnar pulse as well as radial, median, and ulnar nerve motor functions.

CONCLUSIONS

Compared with single CBS training alone, repeated exposure to CCDSS after CBS training resulted in improved documentation of the NV/MSK status of pediatric patients with elbow fracture.

Diagnostic values of conventional conduction parameters in ulnar neuropathy at elbow

BACKGROUND AND PURPOSE

Conventional parameters used in electrodiagnosis of ulnar neuropathy at elbow (UNE) are: (i) absolute across-elbow ulnar nerve motor conduction velocity (MCV), (ii) reduction rate of composed muscle action potential (CMAP) amplitude from above to below elbow stimulation, and (iii) MCV difference between forearm and across-elbow segment. We aimed to search the diagnostic accuracy values of these parameters on UNE, and their correlations with axonal dysfunction of ulnar nerve fibers.

METHODS

Arms with clinical signs of UNE and two-fold healthy controls were included. We detected the best cut off points of the measured parameters and their possible combinations. Their diagnostic accuracy values and correlations with parameters reflecting the axonal functions were analyzed, statistically.

RESULTS

Totally, 118 arms with UNE and 236 controls were included. Absolute across-elbow MCV yielded a higher accuracy than MCV difference and reduction rate of CMAP amplitude (p = 0.010 and p˂0.001, respectively). Besides, combining it with other parameters did not increase the diagnostic yield. Correlation analyses revealed that the only parameter having positive linear correlations with sensory nerve action potential amplitudes both in the control and the disease groups is the absolute across-elbow MCV. The absolute across-elbow MCVs have also positive linear correlation with CMAP amplitudes in disease group.

CONCLUSION

The absolute across-elbow MCV is the most valuable conventional parameter for the electrodiagnosis of UNE. It is also the most correlated parameter with the electrodiagnostic parameters reflecting the axonal functions of the ulnar nerve fibers.

Compression of the Median Nerve and Ulnar Nerve's Deep Palmar Branch by a Ganglion Cyst in the Carpal Tunnel: A Case Report

CASE

A 39-year-old woman presented with a ganglion cyst in the carpal tunnel simultaneously compressing the right median nerve and the deep palmar branch of the ulnar nerve. During surgery, the soft tissue was exposed under the median nerve and on the deep palmar branch of the ulnar nerve running transversely in the deep area of the carpal tunnel.

CONCLUSION

Simultaneous compression of the median nerve and deep palmar branch of the ulnar nerve is extremely rare; however, such a pathoanatomical relationship must be considered while examining a patient because these nerves are located close to each other.

Fragment Excision With Flexor-Pronator Mass Repair for Chronic Medial Humeral Epicondyle Nonunions

Athletes with medial epicondyle nonunions typically present with medial elbow pain, an elbow flexion contracture, and the inability to compete. The purpose of this study was to evaluate the clinical outcomes of patients who underwent medial epicondyle excision with ulnar collateral ligament and flexor-pronator mass repair for symptomatic medial epicondyle non-unions. Four patients with a mean age of 15 years (range, 11-19 years) diagnosed with symptomatic medial epicondyle nonunions were evaluated. All were treated with medial epicondyle excision with ulnar collateral ligament and flexor-pronator mass repair. Two of the patients were followed for 12 months, whereas the other 2 patients were followed for 18 months. All patients returned to their preinjury level of sports without difficulty. Two patients with preoperative flexion contracture had residual flexion contractures of 4° and 5° postoperatively, respectively, as measured by a goniometer. All other patients regained full elbow motion equal to that of the contralateral extremity at final follow-up. The patients with preoperative ulnar nerve symptoms had complete resolution postoperatively at a mean follow-up of 18 months. In overhead and upper extremity weight-bearing athletes who have symptomatic medial epicondyle nonunions, fragment excision with flexor-pronator mass repair can yield satisfactory results. [Orthopedics. 2021;44(3):e337-e342.].

The neurophysiological lesson from the Italian CIDP database

Introduction

Electrophysiological diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) may be challenging. Thus, with the aim ofproviding some practical advice in electrophysiological approach to a patient with suspected CIDP, we analyzed electrophysiological data from 499 patients enrolled inthe Italian CIDP Database.

Methods

We calculated the rate of each demyelinating feature, the rate of demyelinating features per nerve, the diagnostic rate for upper andlower limb nerves, and, using a ROC curve analysis, the diagnostic accuracy of each couple of nerves and each demyelinating feature, for every CIDP subtype.Moreover, we compared the electrophysiological data of definite and probable CIDP patients with those of possible and not-fulfilling CIDP patients, and by a logisticregression analysis, we estimated the odds ratio (OR) to make an electrophysiological diagnosis of definite or probable CIDP.

Results

The ulnar nerve had the highestrate of demyelinating features and, when tested bilaterally, had the highest diagnostic accuracy except for DADS in which peroneal nerves were the most informative.In possible and not-fulfilling CIDP patients, a lower number of nerves and proximal temporal dispersion (TD) measurements had been performed compared to definiteand probable CIDP patients. Importantly, OR for each tested motor nerve and each TD measurement was 1.59 and 1.33, respectively.

Conclusion

Our findingsdemonstrated that the diagnosis of CIDP may be missed due to inadequate or incomplete electrophysiological examination or interpretation. At the same time, thesedata taken together could be useful to draw a thoughtful electrophysiological approach to patients suspected of CIDP.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-021-05321-z.

[A black wound on the lower arm]

A 19-year-old man presented on the Emergency Room on New Year's Eve with a 2 cm-wide black burn located on his lower arm. Earlier that evening he was hit by a piece of firework. Even though he immediately felt a sharp burning pain, he did not realize the severity of the injury. He presented with numbness in the digiti 4 and 5 and the Wartenberg sign, which are signs of an ulnar nerve injury. An exploration of the ulnar nerve was performed. Extensive burns and gunpowder were seen on the flexor carpi radialis and ulnaris muscle, the fascia and the epineurium of the ulnar nerve. However, the ulnar nerve was intact. A week later a babysitting procedure was performed because of absent intrinsic muscle activity, with an end-to-side anastomosis of the anterior interosseous nerve to the motor branch of the ulnar nerve. Hand physiotherapy was started after the operation.

Nerve Conduction Studies in Surgical Cubital Tunnel Syndrome Patients

Background: Electrodiagnostic studies (EDX) serve a prominent role in the diagnostic workup of cubital tunnel syndrome (CBTS), but their reported sensitivity varies widely. The goals of our study were to determine the sensitivity of EDX in a cohort of patients who responded well to surgical cubital tunnel release (CBTR), and whether the implementation of the Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) criteria improves the sensitivity. Methods: We identified 118 elbows with clinical CBTS who had preoperative EDX and underwent CBTR. The EDX diagnoses were CBTS, ulnar neuropathy (UN), and normal ulnar nerves. We divided the 118 elbows into those that received above-elbow stimulation (XE group) and those that did not (non-XE group). We calculated the sensitivities for all groups and reinterpreted the results according to the AANEM guidelines. Results: Cubital tunnel release provided significant relief in 93.6% of the elbows. Based on the EDX reports, 11% patients had clear CBTS, 23% had UN, and 66% showed no UN. The sensitivities were 11.7% for CBTS and 34.2% for any UN. In the XE group, the sensitivity of the EDX reports for CBTS and UN climbed to 33.3% and 58.3%, respectively. When we calculated the across-elbow motor nerve conduction velocity, the sensitivity for CBTS and UN was 87.5% and 100%, respectively. The XE and non-XE groups showed no difference except for sex, bilaterality, concomitant carpal tunnel release, and obesity (P < .05). Conclusion: Implementing AANEM guidelines results in significant improvement in correlation of clinical and electrodiagnostic findings of CBTS.

Ulnar two-point discrimination following endoscopic carpal tunnel release

Carpal tunnel syndrome is median nerve symptomatic compression at the level of the wrist, characterized by increased pressure within the carpal tunnel and decreased nerve function at the level. Carpal tunnel release decreases pressure in Guyon's canal, via open techniques, with symptom and two-point discrimination improvement in the ulnar nerve distribution. We hypothesize that endoscopic carpal tunnel release improves two-point discrimination in the ulnar nerve distribution as well. This study includes 143 patients who underwent endoscopic carpal tunnel release between April 2016 to June 2019 in a single, community-based teaching hospital. A comprehensive retrospective chart review was performed on patient demographics, pre- and post-operative two-point discrimination test results, and complications. The effects of sex, age, and diabetes mellitus in the ulnar and median nerve territories with two-point discrimination tests were analyzed. As well as the differences in two-point discrimination among patient's based on their smoking status. There were significant post operative improvements in both the median (7.7 vs 4.4 mm, p < 0.001) and ulnar (5.7 vs 4.1 mm, p < 0.001) nerve territories. Smoking status, sex, age and diabetes did not significantly affect two-point discrimination outcomes. In conclusion the endoscopic release of the transverse carpal ligament decompresses the carpal tunnel and Guyon's canal, demonstrating improvement in two-point discrimination in both the ulnar and median nerve distributions.

Socioeconomic Factors in Patients with Ulnar Nerve Compression at the Elbow: A National Registry-Based Study

AIMS

To investigate demographics and socioeconomic status in patients with ulnar nerve compression and the influence of socioeconomic factors on patient-reported outcome measurements (PROM) as evaluated by QuickDASH (short version of Disabilities of Arm, Shoulder and Hand) after surgery for ulnar nerve compression at the elbow.

METHODS

Patients operated for primary ulnar nerve compression from 2010 to 2016 were identified in the National Quality Registry for Hand Surgery Procedures (HAKIR). Patients filled out questionnaires before and at three and 12 months after surgery. A total of 1346 surgically treated cases were included. Data from HAKIR were linked to data from Statistics Sweden (SCB) on socioeconomic status (i.e., education level, earnings, social assistance, immigrant status, sick leave, unemployment, and marital status).

RESULTS

Patients surgically treated for ulnar nerve compression at the elbow differed from the general population with lower levels of education, higher social assistance dependence, a high proportion of unemployment, and lower earnings. However, the results were not clear concerning the influence of socioeconomic factors on the outcome of surgery, except for long-term sick leave.

CONCLUSION

Patients surgically treated for ulnar nerve compression at the elbow are socioeconomically deprived, but only a history of long-term sick leave influences the outcome of surgery. This information is crucial in the diagnosis and treatment of these patients.

Optical Analysis of Acute Changes after Peripheral Nerve Injury in Spatio-Temporal Pattern of Neural Response to Forelimb Stimulation in Rat Somatosensory Cortex

Peripheral nerve injury induces functional reorganization of the central nervous system. The mechanisms underlying this reorganization have been widely studied. Our previous study involving multiple-site optical recording reported that a neural excitatory wave induced by somatic stimulation begins in a small area and propagates in the cortex. In the present study, to examine the possible role of this propagation wave in cortical reorganization, we analyzed the early changes in the spatio-temporal pattern of the sensory-evoked wave immediately, and 30 min, after nerve injury. The response to hypothenar stimulation, innervated by the ulnar nerve and adjoining the median nerve area, persisted after injury to either the ulnar or median nerve. Initially, we assessed changes in the response pattern at the focus. The latency increased after ulnar nerve injury, whereas no change was observed after median nerve injury. Similarly, no change was noted in the duration of the response signal with either nerve injury. Second, changes in the propagation wave pattern were analyzed. Ulnar nerve injury decreased the propagation velocity in the medial direction but the median nerve injury induced no changes. These results indicated that the propagation wave pattern is readily altered, even immediately after nerve injury, and suggest that this immediate change in the spatio-temporal pattern is one of the factors contributing to the cortical reorganization.

Cortical connectivity and spectral perturbations underlying TENS stimulation of hand nerves: a case study

The major challenge in upper limbs neuroprosthetic improvement is the implementation of effective sensory feedback. Transcutaneous electrical nerve stimulation (TENS) of the median and ulnar nerves confirmed, with electroencephalographic (EEG) recordings, the presence of appropriate responses in relevant cortical areas with induced sensation successfully located in the innervation regions of each nerve. The characterization of these elicited responses could be used to recreate precise somatotopic feedback from hand protheses. Using TENS and EEG, the purpose of this study was to detect distinctions in time-frequency cortical dynamics and connectivity occurring after stimulation of hand nerves. Region of interest (ROI) were selected according to topographical distributions and Somatosensory Evoked Potentials (SEP) localization and were named Contralateral Parietal (Cont P), Central Frontal (Cent F) and Superior Parietal (Sup P). The analysis of cortical oscillations showed spectral inflections in theta [4-7 Hz] and alpha [7.5-12.5 Hz] band which occurred at 60 ms in Cont P and 300 ms in Sup P and prominent for the ulnar condition over the median one. The beta band decrease [16-30 Hz] which occurred in the same ROIs was especially significant after ulnar stimulation too. Effective connectivity measures did not differ significantly across conditions but exhibited some slight difference in the alpha-band causal flow coming from Cent F in direction to Cont P and Sup P. Although pending completion of multiple-subjects study, these results already suggest magnitude differences in somatosensory spectral fluctuations and sensorimotor interactions flows.

Peripheral Nerve Compression Syndromes in Children

Nontraumatic neuropathies of the upper limb are rare in children. In this paper, we present the latest updates in this field and also critically review the diagnosis and treatment of nerve compression syndromes in children. This review describes the most common manifestations including idiopathic carpal tunnel syndrome (CTS), CTS occurring as a component of lysosomal storage diseases (mucopolysaccharidosis) and hereditary neuropathies, ulnar nerve neuropathy, and atraumatic radial nerve neuropathies.

Modified Lateral Approach of the Elbow for Surgical Release and Synovectomy

Elbow stiffness is a common reason for consultation. In recent years, arthroscopic techniques in elbow surgery have progressed, but there are still some contraindications to performance of arthroscopic synovectomy and release in this joint (elbows with anatomic deformity after multiple procedures, malunion, presence of osteosynthesis material, severe stiffness of >80 degrees, instability, or previous transposition of the ulnar nerve). Therefore, knowledge of a safe and reliable open approach to achieve elbow release and/or synovectomy is essential. We report the technical details of the modified lateral approach between extensor carpi radialis brevis and longus muscles, as well as the clinical results of 43 elbow release and/or synovectomy procedures, illustrating its feasibility. The modified lateral approach, providing visual control of the radial nerve and good anterior exposure of the elbow joint, is detailed. From 1994 to 2016, this approach was used in 43 release and/or synovectomy procedures of the elbow in 41 patients, 30 men and 11 women, with a mean age of 40.56 years (range, 17 to 84 y). Using this procedure, 38 elbows (93%) recovered full extension and 5 subtotal extension with an average deficit of 11 degrees (range, 5 to 20 degrees). All elbows were stable. No neurological complications were reported. The modified lateral approach preserves the insertion of the lateral epicondyle muscles that are major dynamic stabilizers and reduces the risk of instability. Initially described for the treatment of radial tunnel syndrome, it should also be recommended for elbow release and synovectomy.