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.     

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.     

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.     

Ulnar entrapment neuropathy along the medial intermuscular septum in the midarm

We report a patient with primary ulnar entrapment neuropathy in the midarm. Stimulation of multiple sites along the ulnar nerve showed a motor conduction block at a distance of 7.5–10 cm proximal to the medial epicondyle, where the nerve was compressed by the medial intermuscular septum. Anatomically, the possibility of ulnar nerve entrapment in this segment has long been suggested, and stimulation at least 10 cm above the medial epicondyle may reveal the entrapment. Muscle Nerve 39: 707–710, 2009     

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.     

Injection with corticosteroids (ultrasound guided) in patients with an ulnar neuropathy at the elbow,feasibility study

Introduction and purpose: Unlike carpal tunnel syndrome, little is known about injection with corticosteroids in patients with an ulnar neuropathy at the elbow (UNE). The purpose of this feasibility study is to see whether injection with corticosteroids is safe in patients with UNE and whether there are grounds to launch a prospective placebo‐controlled study on the effects of corticosteroids. Methods: Patients with clinical symptoms of UNE and a nerve conduction study compatible with UNE or thickened ulnar nerve at the elbow (> 10 mm²) by ultrasonography were included. All included patients received an ultrasound‐guided injection of 1 ml containing 40 mg methylprednisoloneacetate and 10 mg lidocainhydrochloride (Depo‐Medrol^®). Complications of the injection were monitored. After 3 months, nerve conduction studies and ultrasonography were repeated and a clinical outcome determined. Results: Eight patients with nine UNE were included. None of the patients mentioned increase in the symptoms directly after the injection nor had an infection on the injection site or haematoma. After 3 months, there was improvement of the symptoms in five patients. One patient deteriorated and three had no change of the symptoms at all. Overall, there was no significant change of the thickness of the ulnar nerve with mean difference ?0.056 mm² (95% CI ?2.56 to 2.45 mm²). Conclusion: We showed that injection with corticosteroids in patients with UNE is easy and safe, and based on this result, we found enough arguments to launch a prospective, placebo‐controlled trial to explore the effectiveness of corticosteroids in patients with UNE.     

Intraoperative electroneurography: management of ulnar neuropathy at the elbow

At the elbow the ulnar nerve may be compressed either in the retrocondylar groove or at the cubital tunnel. Optimal surgical therapy should be directed at the specific site of involvement. Intraoperative electroneurography performed in conjunction with 19 ulnar nerve explorations helped localize the precise site of compression. Of the primary procedures, abnormality was at the retrocondylar groove in 9, cubital tunnel in 4, both locations in 3, and at an unusual distal point in 1; 12 anterior subcutaneous transpositions, 4 cubital tunnel releases, and 1 distal decompression resulted. Intraoperative studies helped identify residual compression in two patients undergoing reexploration. Although routine electrodiagnosis may localize an ulnar neuropathy to the elbow, reliably separating retrocondylar from cubital tunnel compression is more difficult. Preoperatively, percutaneous serial short increment studies were more accurate than simple "inching" in predicting the site of compression.     

Ultrasonography in ulnar neuropathy at the elbow: Relationships to clinical and electrophysiological findings

INTRODUCTION: Though ultrasonography (US) is commonly used in the diagnosis of carpal tunnel syndrome (CTS), there are only few studies on the utility of US in ulnar neuropathy at the elbow (UNE). The aims of this study were to measure the cross-sectional area (CSA) of the ulnar nerve at the elbow and to correlate CSA values with clinical and electrophysiological findings. PATIENTS AND METHODS: Thirty-three UNE patients (mean age 50.1 years) were consecutively enrolled. Diagnosis was based on clinical findings and slowing of the motor conduction velocity (MCV) of the ulnar nerve across the elbow. CSAs of the ulnar nerve were measured within the cubital tunnel at the level of the medial epicondyle (CSA-M) and approximately 2cm proximal to this point (CSA-I). Correlations between CSA and demographic, clinical (ordinal severity scale and self-administered symptom questionnaire), and electrophysiological findings (neurographic results and ordinal electrophysiological severity scale) were calculated using Spearman's correlation coefficient. RESULTS: The mean CSA-M and CSA-I were 9.6+/-8.5 and 9.3+/-5.6mm2, respectively. Fifteen (45.5%) and eight (24.5%) cases showed abnormal CSA-M and CSA-I values, respectively (mean+2S.D. compared to a control group of the same age). All cases with abnormal CSA-I had abnormal CSA-M except one. Significant relationships were only found between CSA-M and CSA-I with across elbow MCV, sensory action potential amplitude, and the electrophysiological severity scale score. DISCUSSION: Our study showed anomalous CSA values in less than 50% of the UNE cases. This is less than the reported percentages in the few literature reports. This difference may be due to our enrolment criteria or to the electrophysiological and US techniques. It is likely that the CSAs measured by axial scan at a fixed level of the cubital tunnel may have lower diagnostic sensitivity than the same technique used in CTS.     

Ultrasonographic measurements in cubital tunnel syndrome

The cubital tunnel is the most common site of ulnar nerve entrapment. Previous ultrasound studies have demonstrated enlargement of the ulnar nerve in cubital tunnel syndrome but did not report on the cubital tunnel itself. Twenty-two individuals with cubital tunnel syndrome were evaluated with nerve conduction studies and ultrasound. The ultrasound measurement that most strongly correlated with conduction velocity was the ratio of ulnar nerve to cubital tunnel cross-sectional area with the elbow flexed. Measurement of this ratio may improve the diagnostic accuracy of ultrasound in cubital tunnel syndrome, although further investigation is needed.     

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.     

Lifestyle risk factors for ulnar neuropathy and ulnar neuropathy‐like symptoms

Introduction: We examined whether lifestyle factors differ between patients with ulnar neuropathy confirmed by electroneurography (ENG) and those with ulnar neuropathy‐like symptoms with normal ulnar nerve ENG. Methods: Among patients examined by ENG for suspected ulnar neuropathy, we identified 546 patients with ulnar neuropathy and 633 patients with ulnar neuropathy‐like symptoms. These groups were compared with 2 separate groups of matched community referents and to each other. Questionnaire information on lifestyle was obtained. The electrophysiological severity of neuropathy was also graded. We used conditional and unconditional logistic regression. Results: Responses were obtained from 59%. Ulnar neuropathy was related to smoking, adjusted odds ratio (OR) 4.31 (95% confidence interval [CI] 2.43–7.64) for >24 pack‐years. Ulnar neuropathy‐like symptoms were related to body mass index ≥30 kg/m², OR 1.99 (95% CI 1.25–3.19). Smoking was associated with increased severity of ulnar neuropathy. Conclusions: Findings suggest that smoking specifically affects the ulnar nerve. Muscle Nerve 48 : 507–515, 2013     

Cubital Tunnel Syndrome, Associated With Synovial Chondromatosis

A 62-year-old female patient suffered from numbness and resting pain in the right ring and little fingers for 3 years. We confirmed cubital tunnel syndrome with electrodiagnostic study and performed the operation. We found seven firm consistent nodules, compressing the overlying the ulnar nerve, proximal to the medial epicondyle in the operation field. Histological finding showed synovial chondromatosis. We report a rare case of a patient with cubital tunnel syndrome caused by synovial chondromatosis.     

AANEM Application

Introduction: This anatomical study evaluates the role and correlation of ultrasound (US) with anatomy in depicting the superficial branch of the radial nerve (SBRN) and to evaluate the feasibility of US guided perineural infiltration as a potential therapeutic option in Wartenberg syndrome. Methods: Twenty‐one arms from 11 non‐embalmed cadavers were examined with US. Under US guidance perineural injection with ink was performed proximal to the site where the SBRN perforates the forearm fascia. The distribution of ink around the nerve was evaluated with dissection. Results: US allowed the distinction of the SBRN segments and their relation to the fascia. In all cases, the subfascial segment was stained. In only 57% the subfascially applied ink also reached the subcutaneous compartment. Conclusions: With US it is possible to examine and differentiate all segments of the SBRN. US guidance can be used for perineural injection of all relevant segments. Muscle Nerve 50: 939–942, 2014     

MR在尺神经卡压综合征诊疗中的应用

目的探讨MR在尺神经卡压综合征(CuTS)术前评估、术式选择、术后疗效评估中的应用价值。方法对470例CuTS患者,按Dellon术式对卡压神经行尺神经显微松解减压术。所有患者术前4周病侧组和健侧组尺神经行MR检测对照,术前、术后病侧组尺神经MR检测指标对照。结果 MR显示受累神经肿胀、增粗,信号减低,神经内线状结构消失,肿胀部位(内上髁沟、穿尺侧腕屈肌处)明显受到旋前圆肌、指浅屈肌、肘管、屈肌总腱等组织卡压;神经横截面积(CSA)相比较于健侧差异显著;术前、术后对照:MR尺神经检测结果提示神经卡压明显缓解。结论 MR能够从形态学角度提供神经卡压程度、部位等信息,同时可以清晰显示卡压神经周围解剖,适用于辅助术前评估,指导手术操作,评价手术效果。     

Localization of ulnar neuropathy at the elbow using new stimulator for the inching test.

OBJECTIVE: To evaluate the usefulness of the TenElectrodes, a new stimulator for inching test, in the diagnosis and localization of ulnar neuropathy at the elbow (UNE). METHODS: Sixty-two ulnar nerves in 40 control subjects and 24 ulnar nerves in 23 patients with typical symptoms and signs of UNE were studied. The inching test of ulnar motor nerve using TenElectrodes was done along 8 cm across the elbow in the extended position. RESULTS: In the inching test of the control group, the mean segmental latency difference was 0.19+/-0.08 ms. Maximal latency difference over a 1 cm segment did not exceed 0.40 ms in any of the controls but exceeded 0.5 ms or more in all clinical UNE patients. In all UNE patients, the lesion sites were identified by the inching test using TenElectrodes: the retroepicondylar groove (54.2%), the humeroulnar arcade (29.2%), and dual compression (16.6%). CONCLUSIONS: TenElectrodes is a useful stimulator for the inching test in the diagnosis of UNE. The precise localization of compression was possible in all patients with UNE and the most common site was the retroepicondylar groove.     

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     

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.     

Sparing of the flexor carpi ulnaris in ulnar neuropathy at the elbow

A common misconception attributes sparing of the flexor carpi ulnaris (FCU) in ulnar neuropathy at the elbow (UNE) to its innervating branch arising "at or above the elbow." We examined the relationship of FCU branches to the medial epicondyle (ME) and humeroulnar aponeurotic arcade (HUA) in 30 cadaver elbows. In only three did the first FCU branch arise at or proximal to the ME. In 36 UNE cases with fibrillations in the first dorsal interosseous, the FCU was normal in 10, mildly abnormal in 11, and severely abnormal in 15. FCU involvement correlated with the severity of the neuropathy and with whether compression was retroepicondylar or at the HUA. We conclude that sparing of the FCU in UNE is unrelated to the level of origin of its innervating branch, but rather is related to the internal neural topography and to the severity and level of compression.     

Palmaris brevis sign in ulnar neuropathy

A case of ulnar neuropathy, selectively affecting the deep branch and showing positive palmaris brevis sign, is reported. The palmaris brevis muscle was not only intact, but also showed excessive cocontraction with abductor digiti minimi. Palmaris brevis sign, when present, is useful in clinically localizing the site of the ulnar nerve lesion. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:675–677, 1998.     

Symptomatic epineural ganglion cyst of the ulnar nerve in the cubital tunnel: a case report and brief review of the literature

An unusual case of pain and weakness in the hand and forearm due to a ganglion cyst of the ulnar nerve at the elbow is presented. The patient was managed initially as a case of cervical disc disease and cervical spondylosis and later as a case of carpal tunnel syndrome at an another institution. Cervical radiography and cervical magnetic resonance imaging scans were inconclusive. Neurosurgical referral revealed tenderness at the right cubital tunnel, weakness of the right hand and forearm muscles, and sensory deficit along the medial border of the forearm and the hand. The diagnosis of ulnar nerve compression at the elbow was made. Nerve conduction studies of the ulnar nerve at the elbow confirmed the diagnosis. A ganglion cyst of the ulnar nerve was excised microsurgically with a complete postoperative sensory motor recovery.