Evaluation of patients with recurrent symptoms after ulnar nerve transposition

Focal entrapment of the ulnar nerve occurs most frequently in the region of the elbow, at the ulnar groove or beneath the humeroulnar aponeurosis. Surgical treatment commonly involves transposition of the nerve anterior to the medial epicondyle, in the antecubital fossa. Symptoms may recur after surgery, and, to assess their etiology, we studied 10 patients with recurrent ulnar symptoms after transposition. Conventional motor and sensory conduction studies were performed, as was mapping of nerve position using submaximal stimuli. In 9 of 10 patients, the ulnar nerve at the elbow was located adjacent to the medial epicondyle, rather than in the antecubital fossa. Focal slowing in the region of the elbow was noted in 8 patients, and an additional site of focal slowing was found in the forearm in 3 patients. We conclude that in patients with recurrent symptoms after ulnar nerve transposition postoperative position of the ulnar nerve may be medial, often near the medial epicondyle. This location may predispose the nerve to recurrent trauma or cause traction on the nerve at more distal locations within the forearm. The prevalence of this medial location of the ulnar nerve in asymptomatic postsurgical patients is unknown.     

A reliable technique for ultrasound‐guided perineural injection in ulnar neuropathy at the elbow

Introduction: Ulnar neuropathy at the elbow (UNE) is a common peripheral compression neuropathy and, in most cases, occurs at 2 sites, the retroepicondylar groove or the cubital tunnel. With regard to a potential therapeutic approach with perineural corticosteroid injection, the aim of this study was to evaluate the distribution of injection fluid applied at a standard site. Methods: We performed ultrasound‐guided (US‐guided) perineural injections to the ulnar nerve halfway between the olecranon and the medial epicondyle in 21 upper limbs from 11 non‐embalmed cadavers. In anatomic dissection we investigated the spread of injected ink. Results: Ink was successfully injected into the perineural sheath of the ulnar nerve in all 21 cases (cubital tunnel: 21 of 21; retroepicondylar groove: 19 of 21). Conclusion: US‐guided injection between the olecranon and the medial epicondyle is a feasible and safe method to reach the most common sites of ulnar nerve entrapment. Muscle Nerve 56 : 237–241, 2017     

The cubital tunnel syndrome: diagnosis and precise localization

The cubital tunnel syndrome is a subgroup of ulnar neuropathies arising at the elbow, with nerve entrapment under the aponeurosis connecting the two heads of the flexor carpi ulnaris muscle. To separate this condition more clearly from tardy ulnar palsy, the clinical and electrophysiological features of 9 patients are presented, 6 of whom had the syndrome bilaterally. There was no history of trauma and no clinical or roentgenographic evidence of joint deformity in any of the patients. In 9 of the 15 ulnar nerves, abnormal conduction was localized to the level of the cubital tunnel (1.5 to 3.5 cm distal to the medial epicondyle). The findings were confirmed intraoperatively in 7 patients and corresponded to a tight band compressing the ulnar nerve and causing narrowing at the cubital tunnel with swelling proximally. This syndrome represents a common and distinct subgroup of ulnar neuropathies at the elbow.     

Variations in anatomy of the ulnar nerve at the cubital tunnel: pitfalls in the diagnosis of ulnar neuropathy at the elbow.

Two processes account for most instances of ulnar neuropathy at the elbow: compression in the retroepicondylar groove, and compression by the humeroulnar aponeurotic arcade joining the two heads of the flexor carpi ulnaris. While conventional electrodiagnostic criteria may localize an ulnar neuropathy to the elbow, separating retroepicondylar compression from humeroulnar arcade compression is more difficult. In 130 cadaver elbows, we examined the relationships between the medial epicondyle, flexor carpi ulnaris, and ulnar nerve. The humeroulnar arcade lay from 3 to 20 mm distal to the medial epicondyle, the intramuscular course of the nerve through the flexor carpi ulnaris ranged from 18 to 70 mm, and the nerve exited the flexor carpi ulnaris 28 to 69 mm distal to the medial epicondyle. In 6 specimens, dense fibrous bands bridged directly between the medial epicondyle and the olecranon proximal to the cubital tunnel proper; accessory epitrochleoanconeus muscles were present in 14 specimens: both may cause ulnar neuropathy at the elbow. Anatomical variations may contribute to the difficulty in separating causes of ulnar neuropathy at the elbow.     

An unusual location of ulnar nerve pathology: a perineurioma of the ulnar nerve in the upper arm

A young man presented with progressive motor weakness and atrophy of the ulnar muscles of his left hand over a period of more than 2 years. Electrodiagnostic studies indicated an ulnar nerve lesion, but it was not localized. High-resolution sonography of the ulnar nerve revealed an enlarged and hypoechogenic ulnar nerve at an unusual location, namely 12.5 cm proximal to the medial epicondyle. Histology showed that this was an intraneural perineurioma. High-resolution sonography of the ulnar nerve is very useful in the discovery of this unusual location of nerve pathology and may assist in its early detection.     

Proximal Martin-Gruber anastomosis mimicking ulnar neuropathy at the elbow.

We present a case of Martin-Gruber anastomosis (MGA) mimicking conduction block between the above- and below-elbow sites of ulnar nerve stimulation. We review the anatomical and electrophysiological literature on this subject and discuss its clinical implications. The potential for a MGA to occur very proximally in the forearm and thus mimic ulnar neuropathy at the elbow is underrecognized. We recommend that a check for MGA be performed on all patients with an apparent conduction block at the elbow, and suggest that 3 cm distal to the medial epicondyle may be an optimal below-elbow ulnar nerve stimulation site.     

Applied anatomical study of the vascularized ulnar nerve and its blood supply for cubital tunnel syndrome at the elbow region

Cubital tunnel syndrome is often accompanied by paresthesia in ulnar nerve sites and hand muscle atrophy. When muscle weakness occurs, or after failure of more conservative treatments, anterior transposition is used. In the present study, the ulnar nerve and its blood vessels were examined in the elbows of 18 adult cadavers, and the external diameter of the nutrient vessels of the ulnar nerve at the point of origin, the distances between the origin of the vessels and the medial epicondyle of the humerus, and the length of the vessels accompanying the ulnar nerve in the superior ulnar collateral artery, the inferior ulnar collateral artery, and the posterior ulnar recurrent artery were measured. Anterior transposition of the vascularized ulnar nerve was performed to treat cubital tunnel syndrome. The most appropriate distance that the vascularized ulnar nerve can be moved to the subcutaneous tissue under tension-free conditions was 1.8 ± 0.6 cm(1.1–2.5 cm), which can be used as a reference value during the treatment of cubital tunnel syndrome with anterior transposition of the vascularized ulnar nerve.     

The location of conduction abnormalities in human entrapment neuropathies.

Direct stimulation of 23 median, 13 ulnar and 2 peroneal nerves at the time of surgical exploration has been used to locate, and characterize the conduction abnormalities in the nerves. The most frequent location of the major conduction abnormalities in the median nerve was in the first 1-2 cm distal to the origin of the carpal tunnel. In the ulnar nerve the important conduction abnormalities were located most frequently in the segments 1 cm proximal and distal to the medial epicondyle. In the peroneal nerve the major conduction abnormalities occurred proximal or distal to the entry point of the common peroneal nerve into the peroneus longus muscle.     

Localization of ulnar neuropathy with conduction block across the elbow

We performed short segment incremental stimulation on 13 consecutive patients with ulnar neuropathy across the elbow (UNE) and conduction block. Conduction block occurred proximal to the medial epicondyle in 62%, at the epicondyle in 23%, and below the elbow in 15%. The ulnar nerve may be more prone to external compression above the elbow than previously recognized. Short segment incremental studies are useful to identify conduction block above the elbow in such patients.     

New near-nerve needle nerve conduction technique: differentiating epicondylar from cubital tunnel ulnar neuropathy.

At the elbow, the ulnar nerve is compressed most commonly either in the epicondylar groove or at the cubital tunnel. While conventional electrodiagnosis may localize an ulnar neuropathy to the elbow, separating epicondylar syndrome (tardy ulnar nerve palsy) from cubital tunnel syndrome is more difficult. We describe a new method using a near-nerve needle technique for distinguishing these two types of ulnar neuropathy at the elbow. We placed three active needle electrodes across the elbow: the first was 4 cm above, and the second and third were 1.5 cm and 6 cm below the medial epicondyle, respectively. The latter two points were chosen because of the presence of the cubital tunnel in this segment. Sensory, motor, and mixed nerve conduction studies (NCS) were performed on these two segments (elbow segment and cubital tunnel segment) in 26 normal nerves and normal data were established. We also present 7 cases of epicondylar ulnar nerve palsy and 1 case of cubital tunnel syndrome in which we were able to confirm the diagnosis with the present method. In 3 cases of epicondylar ulnar nerve palsy, the present method accurately localized the lesion when other methods failed. We believe that this method will be helpful in distinguishing cubital tunnel syndrome from epicondylar ulnar nerve palsy, especially in early ulnar neuropathy in which only sensory fibers are involved.     

Patterns and parameters describing nerve thickening in compression and entrapment ulnar neuropathies at the elbow

ObjectiveTo compare pattern and parameters describing nerve thickening in ulnar neuropathy at the elbow (UNE) due to external compression in the retrocondylar groove (RTC), and entrapment under the humeroulnar aponeurosis (HUA).MethodsIn a group of our previously reported UNE patients we ultrasonographically (US) measured ulnar nerve cross-sectional areas (CSA) on 6–8 standard locations in the elbow segment. We compared CSA patterns in both groups, and determined diagnostic utility of selected CSA based parameters.ResultsWe studied 79 patients (81 arms) with UNE due to external compression, and 53 patients (55 arms) due to entrapment. Maximal ulnar nerve CSA (>16 mm²), maximal CSA change (>7 mm²/1–2 cm) and maximal/minimal CSA ratio (>2.6) were significantly larger in UNE due to entrapment. They also differentiated these arms from arms with compression with sensitivities of 78%, 87% and 80%, and specificities of 90%, 94%, and 85%, respectively.ConclusionMaximal difference in CSA between points separated by 1–2 cm (>7 mm²/1–2 cm) very efficiently differentiated between UNE due to external compression and entrapment.SignificanceThe proposed parameter will hopefully complement precise localization in determining underlying mechanism of UNE. This may help physicians to determine the most appropriate treatment for UNE and possibly other focal neuropathies of unknown cause; i.e., conservative treatment for external compression and surgery for entrapment.     

Short-segment nerve conduction studies in ulnar neuropathy at the elbow

The aim of the study was to assess the diagnostic value of short-segment nerve conduction studies (NCS) at 2-cm intervals from 4 cm above to 4 cm below the medial epicondyle in a large group of patients with ulnar neuropathy at the elbow (UNE). Furthermore, we wanted to compare electrodiagnostic and clinical findings. We evaluated 73 arms in 70 patients with UNE and observed the following abnormalities on short-segment NCS: focal conduction block (CB) in 1, focal CB with increased latency change in 34, and increased latency change alone in 25. Short-segment NCS had an additional localizing value in 28 arms of the 37 patients (76%) with motor conduction velocity (MCV) slowing across the elbow only or with nonlocalizing electrodiagnostic findings. The lesion was located above the elbow in 32 arms (53%), at the epicondyle in 16 arms (27%), and below the epicondyle in 12 (20%) of the 60 arms with focal CB or increased latency change on short-segment NCS. Patients with CB on routine and short-segment NCS had muscle weakness significantly more often than patients without CB. Thus, short-segment NCS are useful in localizing the lesion in patients with UNE and CB on routine NCS and have additional diagnostic value in patients with MCV slowing across the elbow or with nonlocalizing signs on routine nerve conduction studies. We recommend its use in all patients in whom UNE is suspected.     

Anomalous intrinsic hand muscle innervation in median and ulnar nerve lesions: An electrophysiological study

A case with a median nerve lesion at the wrist without thenar atrophy and another with an ulnar nerve lesion at the elbow sparing the first dorsal interosseous are reported. Simultaneous multiple channel recording demonstrated in the first case a dual innervation of the abductor pollicis brevis by median and ulnar fibers via a Martin-Gruber anastomosis. In the second case, the cross over of the median fibers innervating the first dorsal interosseous was very proximal in the antecubital fossa. Stimulation at discrete points documented that the communicating fibers from the median joined the ulnar nerve 3 cm below the medial epicondyle.

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Sommario Vengono descritti due casi: il primo con una lesione del nervo mediano al polso senza atrofia della eminenza thenar, il secondo con una lesione del nervo ulnare al gomito che risparmiava il muscolo primo interosseo dorsale. La tecnica di registrazione simultanea con canali multipli ha consentito di dimostrare nel primo caso una innervazione duplice (mediano ed ulnare) del muscolo adbuttore breve del pollice tramite una anastomosi di Martin-Gruber. Nel secondo caso, l'incrocio verso il nervo ulnare delle fibre a partenza dal mediano e destinate ad innervare il muscolo primo interosseo dorsale, era molto prossimale nella fossa antecubitale. La stimolazione nervosa in punti discreti permetteva di dimostrare che le fibre anastomotiche provenienti dal nervo mediano si univano all'ulnare 3 cm al di sotto dell'epicondilo mediale.

     

Entrapment of motor nerves in motor neuron disease: does double crush occur?

OBJECTIVE: To investigate whether "diseased nerves" are more prone to entrapment neuropathy than normal nerves. Nerve conduction studies of human neuropathies have shown that electrophysiological abnormalities are often most prominent at potential sites of nerve entrapment, and entrapments are more common in patients with radiculopathies--a concept designated as "double crush". As entrapment neuropathies commonly occur in otherwise healthy subjects, it is unclear whether this relation is coincidental or whether peripheral nerves affected by disease are rendered more susceptible to effects of repeated minor trauma, traction, or mechanical compression. METHODS: Sequential ulnar nerve conduction studies were prospectively performed at baseline and at four, eight, and 12 month intervals in 16 patients with amyotrophic lateral sclerosis. Ulnar nerve entrapment was defined as a focal reduction (> 10 m/s) in conduction velocity in the across-elbow segment. RESULTS: Ulnar sensory and motor nerve fibres showed similar findings of ulnar nerve entrapment at baseline and at follow up over the period of the study. Nerves with ulnar nerve entrapment showed a significantly greater reduction in distal motor amplitudes than nerves without entrapment, even though distal ulnar sensory amplitudes remained unchanged. CONCLUSIONS: Motor nerves in motor neuron disease do not seem to be more susceptible to entrapment at the elbow than do healthy sensory nerves, thus casting doubt on the double crush hypothesis. Nerves with double pathology (amyotrophic lateral sclerosis and ulnar nerve entrapment), however, seem to undergo more rapid axonal loss than do nerves with single pathology (amyotrophic lateral sclerosis or ulnar nerve entrapment alone).     

Entrapment neuropathy of the ulnar nerve by a constriction band: the role of MRI.

The diagnosis of ulnar nerve entrapment at the elbow has relied primarily on clinical and electrodiagnostic findings. Magnetic resonance imaging (MRI) has been used in the evaluation of peripheral nerve entrapment disorders to document signal and configurational changes in nerves. In this case report we review the MRI and operative findings of a rare constriction band causing ulnar nerve compression at the elbow. We review the sensitivity and specificity in diagnosing ulnar nerve entrapment at the elbow as defined by MRI findings.     

高频超声检测中国贵阳地区汉族人群正中神经的正常值

通过高频超声对245例贵阳地区汉族正常志愿者上肢正中神经腕横纹、腕管入口、腕管出口、腕横纹上6cm、正中神经穿出旋前圆肌处、肱骨内髁上4cm、肱骨中点的横截面积值的分析,发现受试者左右两侧正中神经横截面积值接近,但男性在腕横纹上6cm,肱骨内髁上4cm,肱骨中点处的正中神经面积大于女性,中老年腕横纹、腕管入口和腕管出口处的正中神经横截面积大于青年,且与体质量及身高有关,说明检测上肢正中神经横截面积有助于区别于异常状态。     

The electrodiagnosis of ulnar nerve entrapment at the elbow

Entrapment of the ulnar nerve at the elbow is the second most common focal peripheral neuropathy. Recent advances have facilitated the electrodiagnosis of this common nerve entrapment. The goals of electrodiagnosis are to localize ulnar nerve dysfunction, confirm that the disturbance is confined to the ulnar nerve, and assess the severity of ulnar nerve dysfunction. The goal of this review is to highlight the important advances in anatomy, neurophysiology and methodology that impact upon the electrodiagnosis of entrapment of the ulnar nerve at the elbow, illustrate the limits of electrodiagnosis, and discuss methodological issues that may be the subject of further study. Careful attention to elbow position, temperature, and conservative estimates of conduction block should be part of common practice. Awareness of anatomical variations in structural anatomy, anomalous innervation and fascicular arrangement of ulnar nerve fibers are required to interpret electrodiagnostic studies accurately. The most reliable finding is slowing of the ulnar across-elbow motor nerve conduction velocity to less than 50 m/sec while recording from the abductor digiti minimi muscle, and should be carefully interpreted in the presence of a polyneuropathy or other neurogenic process. Alternative techniques such as relative ulnar slowing in different ulnar nerve segments, use of alternative muscles, sensory and mixed nerve techniques provide complementary information, and like all nerve conduction studies are highly operator-dependent and should be used on a case by case basis. Recent studies have focused the electromyographer's attention on the use of shorter across-elbow segments (2-5 cm). This may offer a reasonable trade-off between sensitivity and measurement error and may result in improved electrodiagnosis.     

Entrapment neuropathies and polyneuropathies in joint hypermobility syndrome/Ehlers–Danlos syndrome

ObjectiveThis study aims to investigate the involvement of the peripheral nervous system in Ehlers–Danlos syndromes/hypermobility type patients with particular attention to entrapment syndromes.MethodsWe consecutively enrolled Ehlers–Danlos syndromes/hypermobility type patients. Patients underwent clinical, neurophysiological and ultrasound evaluations. Dynamic ultrasound evaluation was also performed in healthy subjects as control group.ResultsFifteen Ehlers–Danlos syndromes/hypermobility type patients and fifteen healthy subjects were enrolled. Most of patients presented tingling, numbness, cramps in their hands or feet. Clinical evaluation was normal in all patients. One patient was affected with carpal tunnel syndrome and one with ulnar nerve entrapment at elbow. One patient had an increased and hypoechoic ulnar nerve at elbow at ultrasound evaluation. Dynamic ultrasound evaluation of ulnar nerve at elbow showed, in patients, twelve subluxations and three luxations. In the control group dynamic evaluation showed one case of ulnar nerve luxation.ConclusionStatistical analysis showed a significant difference in the occurrence of ulnar nerve subluxation and luxation between patients and control subjects.SignificanceThe study shows an inconsistency between symptoms and neurophysiological and ultrasound evidences of focal or diffuse nerve involvement. The high prevalence of ulnar nerve subluxation/luxation at elbow in Ehlers–Danlos syndromes/hypermobility type patients could be explained by the presence of Osborne ligament laxity.     

单纯尺神经肘部卡压与糖尿病尺神经肘部病变手术操作的差 异简

目的探讨单纯尺神经肘部卡压和糖尿病尺神经肘部病变手术操作的差异。方法回顾性分析43例尺神经肘部卡压病人的临床资料，单纯尺神经肘部卡压（单纯卡压组）31例（单侧病变27例，双侧病变4例），糖尿病尺神经肘部病变（糖尿病组）12例（单侧病变2例，双侧病变10例），均行肘部尺神经显微减压术。结果单纯卡压组症状缓解28例，无效3例。缓解率90．3％；糖尿病组症状缓解11例，无效1例，缓解率91．7％。无严重并发症。结论单纯尺神经肘部卡压手术操作重点是解除机械性卡压，将尺神经从周围的瘢痕组织中游离出来。糖尿病尺神经肘部病变手术操作重点是清除肘管内外渗出物．游离肘部尺神经与周围组织间的黏连。     

Ultrasonography in patients with ulnar neuropathy at the elbow: Comparison of cross‐sectional area and swelling ratio with electrophysiological severity

The aim of this study was to determine the diagnostic value of ultrasonographic measurements in ulnar neuropathy at the elbow (UNE) and to assess the relationship between the measurements and the electrophysiological severity. The largest anteroposterior diameter (LAPD) and cross‐sectional area (CSA) measurements of the ulnar nerve were noted at multiple levels along the arm, and the distal‐to‐proximal ratios were calculated. Almost all of the measurements and swelling ratios between patients and controls showed statistically significant differences. The largest CSA, distal/largest CSA ratio, CSA at the epicondyle, and proximal LAPD had larger areas under the curve than other measurements. The sensitivity and specificity in diagnosing UNE were 95% and 71% for the largest CSA, 83% and 85% for the distal/largest CSA ratio, 83% and 81% for the CSA at the epicondyle, and 93% and 43% for the proximal LAPD, respectively. There was a statistically significant correlation between the electrophysiological severity scale score (ESSS) and the largest CSA, the CSA at the epicondyle and 2 cm proximal to the epicondyle, and the LAPD at the level of the epicondyle (P < 0.05). None of the swelling ratios showed a significant correlation with the ESSS. The largest CSA measurement is the most valuable ultrasonographic measurement both for diagnosis and determining the severity of UNE. Muscle Nerve, 2010