Laterality and risk factors for ulnar neuropathy at the elbow.

BACKGROUND: Ulnar neuropathy at the elbow (UNE) is the second commonest entrapment neuropathy after carpal tunnel syndrome (CTS) and yet the laterality is not well delineated. Our aim was to establish the laterality of UNE in a large cohort of patients. METHODS: All new patients with clinical and electrodiagnostic (EDX) confirmed UNE over a 13-year period were included. We used multivariate analysis to examine potential predictors of laterality, and unilateral vs bilateral UNE. RESULTS: Of 880 cases, 61% were left-sided and 39% right-sided. These proportions did not change regardless of the handedness of the patient. Patients with bilateral UNE were much more likely to be older male and have a variety of comorbidities. CONCLUSIONS: UNE appears to be present on the left 50% more often than on the right, regardless of the patient's handedness.

The external elbow measure as surrogate of the anatomical width of cubital groove and possible risk factor of ulnar neuropathy at the elbow.

Introduction: There are no studies on elbow anthropometry in ulnar neuropathy at the elbow (UNE). We aimed to test the interrater agreement of external elbow measurements with caliper, the matching of external width of cubital groove (WCG) measures with those obtained through conventional radiography (XR) and ultrasonography (US). The final aim was to evaluate the differences of anthropometric elbow and body measures between UNE cases and controls with multicenter prospective study.Materials and methods: After common training of five observers for external elbow and body anthropometric measurements, we assessed the interrater agreement of measures in a single blind measurement session in 16 healthy volunteers. Then we verified if external WCG measures in eight and four of the above 16 subjects matched with those obtained with US and XR. Finally, we enrolled 40 consecutive idiopathic UNE cases in four electromyographic labs matched for sex and age with 40 controls to evaluate the differences of anthropometric measures.Results: There was high interrater agreement of all anthropometric body and elbow measures (Kendal's and interclass correlation coefficients between 0.84 and >0.9). We found high relations between WCG caliper measures and those obtained with US and XR (r > 0.9). WCG was smaller in cases than in controls (13.2 vs.15.7 mm, p < 0.001). There were no differences in body anthropometric measures (BMI and waist-to-hip ratio).Conclusion: The external measurement of WCG is reliable and reproducible and may be risk factor of UNE. Future studies should be performed in lager samples evaluating the relations with lifestyle and occupational factors.

Late-onset ulnar neuritis following treatment of lepromatous leprosy infection.

Neuritis is a frequent complication of Myocobacteria leprae infection and treatment due to the variety of mechanisms through which it can occur. Not only can mycobacterial invasion into peripheral nerves directly cause damage and inflammation, but immune-mediated inflammatory episodes (termed leprosy reactions) can also manifest as neuritis at any point during infection. Treatment of leprosy reactions with thalidomide can also lead to neuritis due to an adverse drug effect. Neuritis can emerge years after initial diagnosis and treatment, although it is most frequently found at time of diagnosis or early into the treatment course. Treatment of neuritis is dependent on high-dose corticosteroid therapy as well as therapy for suspected underlying etiology. Here, we present a case of ulnar neuritis presenting in a patient with lepromatous leprosy four years after treatment of initial infection, with subsequent improvement after corticosteroid burst while maintained on thalidomide therapy.

Ulnar neuropathy with abnormal non-localizing electrophysiology: Clinical, electrophysiological and ultrasound findings.

OBJECTIVE: To systematically study demographic, clinical, electrophysiological and nerve ultrasound characteristics of ulnar neuropathy with abnormal non-localizing electrophysiology (NL-UN) and further define the utility of ultrasound over and above the conventional electro-diagnostic approach. METHOD: NL-UNs were prospectively identified from 113 consecutive referrals with suspected ulnar neuropathy. All received electro-diagnostic tests and ulnar nerve ultrasound. NL-UN severity was graded using clinical and electrophysiological scales. RESULTS: In 64 of 113 referrals, an ulnar mono- neuropathy was confirmed by electrophysiology. Sixteen of these 64 (25%) had NL-UN, predominantly males (14 out of 16 patients) with severe or moderate clinical and electrophysiological ratings. Ultrasound showed focal ulnar neuropathy at the elbow in 13 out of 16, and diffuse ulnar nerve abnormality in three, and identified a likely or possible causative mechanism in 11. CONCLUSION: A significant proportion (a quarter) of ulnar neuropathies with abnormal electrophysiology were NL-UN, of heterogeneous etiology; the majority were males with significant disability and axonal loss. Ultrasound had a significant role in localization and classification that facilitated management. SIGNIFICANCE: To our knowledge, this is the first systematic prospective study that analyzes the demographic, clinical, electrophysiological and ultrasound characteristics of NL-UN in a routine clinical neurophysiology setting.

Ulnar neuropathy at wrist: entrapment at a very "congested" site.

Ulnar tunnel syndrome indicates ulnar neuropathy at different sites within the wrist. Several classifications of ulnar tunnel syndrome are present in literature, based upon typical nerve anatomy. However, anatomical variations are not uncommon and can complicate assessment. The etiology is also complex, due to the numerous potential causes of entrapment. Clinical examination, neurophysiological testing, and imaging are all used to support the diagnosis. At present, many therapeutic approaches are available, ranging from observation to surgical management. Although ulnar neuropathy at the wrist has undergone extensive prior study, unresolved questions on diagnosis and treatment remain. In the current paper, we review relevant literature and present the current knowledge on ulnar tunnel syndrome.

Functional Ulnar Nerve Paraganglioma: First Documented Occurrence in the Extremity With Hitherto Undescribed Associated Extensive Glomus Cell Hyperplasia and Tumorlet Formation.

Extra-adrenal paraganglioma has never been described in the extremities. A 34-year-old woman complained of an enlarging mass in the right forearm for 18 months. Imaging showed a circumscribed vascular tumor attached to the ulnar nerve; biopsy revealed features of paraganglioma. The resected tumor consisted of zellballen pattern of chief cells staining positively for chromogranin with surrounding S100-positive sustentacular cells. The chief cells contained many neurosecretory granules and mitochondria, whereas the sustentacular cells contained a large amount of rough endoplasmic reticulum and some microfilaments. There was adjacent extensive glomus cell hyperplasia and tumorlet formation. The intraoperative blood pressure dropped abruptly on tumor removal. The serum normetanephrine level decreased from a preoperative level of 1987 pg/mL (normal < 149 pg/mL) to normal after operation. The patient admitted on questioning to a history of paroxysmal attacks of transient palpitation, hand tremors, and sweating; imaging showed no evidence of tumor in other parts of the body, and there was no family history of similar tumor; she remained well 33 months after the operation. This occurrence of functional ulnar nerve paraganglioma with the hitherto undescribed associated glomus cell hyperplasia and tumorlet formation attests to the probable existence of normal sympathetic paraganglia in the extremity and their intimate functional relationship with glomus bodies.

Bilateral position-related ulnar neuropathy at elbow in pediatric population and review of the literature.

Perioperative ulnar neuropathies attributed to inappropriate arm positioning and padding during surgical procedures are commonly found in adults. However, their extremely rare incidence in the pediatric population may cause absent awareness of the risk of nerve injury in anesthetized pediatric patients. Furthermore, young patients respond to conservative treatment of neuropathy less favorably than adults and their response also depends on the pathomechanism of the ulnar nerve injury. A surgeon's or anesthetist's failure to recognize all of these specifics in children may result in substantial morbidity of young patients leading to lawsuits. Fortunately, with an adequate knowledge of surgical anatomy and types of procedures and positions in which the ulnar nerve is particularly vulnerable, and familiarity with measures to minimize the potential for neuropathy, this serious complication can be prevented. The aims of this review are to highlight personal experience and current knowledge of the rare position-related ulnar neuropathy, both from a clinical and anatomical-pathophysiological perspective, and to raise awareness about this rare but serious complication in the pediatric population.

Electrophysiologic features of ulnar neuropathy in childhood and adolescence.

OBJECTIVE: To analyze patterns of nerve injury in pediatric ulnar neuropathy (PUN). METHODS: Retrospective analysis of 49 children with PUN. RESULTS: Sensory loss in digit V was the prevailing complaint (89%). Predominant localization was at the elbow (55%). Diminished ulnar SNAP was the most common abnormality (71%) with median axon loss estimate (MAXE) of 62%. Dorsal ulnar cutaneous (DUC) sensory nerve action potential (SNAP) was reduced in 55% with MAXE of 43%. Abductor digiti minimi (ADM) and first dorsal interosseous (FDI) compound muscle action potential (CMAP) were reduced half of the time, with MAXE of 30% and 28% respectively. There was high correlation between ulnar sensory MAXE and ADM MAXE (r=0.76, p<0.0001), FDI MAXE (r=0.81, p<0.0001) and DUC MAXE (r=0.60, p=0.0048). Neurogenic changes were seen in the ADM, FDI, flexor carpi ulnaris (FCU) and flexor digitorum profundus IV (FDP IV) in 79%, 77%, 25% and 35% respectively. Pathophysiology was demyelinating in 27%, axonal in 59% and mixed in 14%. CONCLUSIONS: In proximal axonal lesions, sensory fibers to digit V and motor fibers to distal muscles are predominantly affected, whereas in demyelinating lesions, slowing occurs twice as frequently as conduction block. SIGNIFICANCE: There is frequent axonal and fascicular injury in PUN.

Intraneural Ganglion Cyst of the Ulnar Nerve at the Elbow Masquerading as a Malignant Peripheral Nerve Sheath Tumor.

BACKGROUND: Ulnar neuropathy at the elbow (UNE) is the second most common mononeuropathy of the upper extremity. One rare cause of UNE is nerve mass lesions, including intraneural ganglion cysts (IGCs). IGC imaging studies provide important information that may determine the nature of a peripheral nerve mass lesion. CASE DESCRIPTION: We present the case of a 73-year-old woman who presented with rapid deterioration of left hand function over 2 months with weakness of fine motor control, grip strength, and dysesthesia in the ulnar nerve distribution. Preoperative imaging studies, including magnetic resonance imaging (MRI) of the elbow, postcontrast studies, diffusion-weighted imaging, and apparent diffusion coefficient measurements, suggested a highly cellular tumor. Diffusion tensor tractography also revealed imaging features suggestive of a malignant peripheral nerve sheath tumor. During the operation, a sample of the lesion was sent for frozen section. There were no features of malignancy, and the pathologist could not determine a diagnosis based on the tissue sample sent. An intraoperative decision was made not to divide the ulnar nerve above and below the lesion. The IGC was successfully managed by identifying a suitable plane of dissection and cyst resection. CONCLUSIONS: This case demonstrates that MRI studies indicating malignant peripheral nerve sheath tumor must be considered with some caution and corroborated with supportive features on operative inspection and biopsy before radical resection is undertaken. Furthermore, for any nerve mass lesion immediately adjacent to a joint, the differential diagnosis of an IGC should be considered.

Ulnar nerve sonography in leprosy neuropathy.

A 23-year-old woman presented with a half-year history of right forearm sensory and motor dysfunction. Ultrasound imaging revealed definite thickening of the right ulnar nerve trunk and inner epineurium, along with heterogeneous hypoechogenicity and unclear nerve fiber bundle. Color Doppler exhibited a rich blood supply, which was clearly different from the normal ulnar nerve presentation with a scarce blood supply. The patient subsequently underwent needle aspiration of the right ulnar nerve, and histopathological examination confirmed that granulomatous nodules had formed with a large number of infiltrating lymphocytes and a plurality of epithelioid cells in the fibrous connective tissues, with visible atypical foam cells and proliferous vascularization, consistent with leprosy. Our report will familiarize readers with the characteristic sonographic features of the ulnar nerve in leprosy, particularly because of the decreasing incidence of leprosy in recent years.

High resolution sonographic examination: a newer technique to study ulnar nerve neuropathy in leprosy.

Objectives: A prospective case control study was conducted to calculate normal dimensions of ulnar nerve and study the size, echotexture and morphologic alterations in ulnar nerve in patients with leprosy. Methods: The study group included 48 patients diagnosed with leprosy on basis of clinical, bacteriologic and/or histopathologic evaluation. Sonographic measurements were taken at 3 levels around elbow. The morphology and vascularity were also studied. Control group consisted of 60 clinically normal ulnar nerves, on which ultrasound was performed to calculate normal parameters. 96 Ulnar nerves were independently evaluated clinically and on ultrasound. The mean cross sectional area and diameters (both antero-posterior and mediolateral) of controls at all three levels were calculated. The normal sonographic dimensions of ulnar nerve were calculated based on Mean ± 2SE and beyond the upper limit of normal was considered enlarged on ultrasound. Statistical analysis was done using SSPS version 17.0. Results: The dimensions of ulnar nerve were significantly larger in leprosy group for all levels (P value , 0.001). Sonographic abnormalities included hypoechoic areas (61·45%), loss of fascicular pattern (same 61·45%) and focal hyperechoic areas (48·95%). 37·5% of nerves (6 out of 16) with clinical evidence of reaction showed endoneural vascularity. Conclusions: We conclude that by detecting enlargement and/or morphologic alterations of ulnar nerve, sonography can objectively determine involvement of ulnar neuropathy in leprosy.

Pure neuritic leprosy presenting as ulnar nerve neuropathy: a case report of electrodiagnostic, radiographic, and histopathological findings.

Hansen's disease, or leprosy, is a chronic infectious disease with many manifestations. Though still a major health concern and leading cause of peripheral neuropathy in the developing world, it is rare in the United States, with only about 150 cases reported each year. Nevertheless, it is imperative that neurosurgeons consider it in the differential diagnosis of neuropathy. The causative organism is Mycobacterium leprae, which infects and damages Schwann cells in the peripheral nervous system, leading first to sensory and then to motor deficits. A rare presentation of Hansen's disease is pure neuritic leprosy. It is characterized by nerve involvement without the characteristic cutaneous stigmata. The authors of this report describe a case of pure neuritic leprosy presenting as ulnar nerve neuropathy with corresponding radiographic, electrodiagnostic, and histopathological data. This 11-year-old, otherwise healthy male presented with progressive right-hand weakness and numbness with no cutaneous abnormalities. Physical examination and electrodiagnostic testing revealed findings consistent with a severe ulnar neuropathy at the elbow. Magnetic resonance imaging revealed diffuse thickening and enhancement of the ulnar nerve and narrowing at the cubital tunnel. The patient underwent ulnar nerve decompression with biopsy. Pathology revealed acid-fast organisms within the nerve, which was pathognomonic for Hansen's disease. He was started on antibiotic therapy, and on follow-up he had improved strength and sensation in the ulnar nerve distribution. Pure neuritic leprosy, though rare in the United States, should be considered in the differential diagnosis of those presenting with peripheral neuropathy and a history of travel to leprosy-endemic areas. The long incubation period of M. leprae, the ability of leprosy to mimic other conditions, and the low sensitivity of serological tests make clinical, electrodiagnostic, and radiographic evaluation necessary for diagnosis. Prompt diagnosis and treatment is imperative to prevent permanent neurological injury.

Anatomical considerations of fascial release in ulnar nerve transposition: a concept revisited.

OBJECT: Surgical transposition of the ulnar nerve to alleviate entrapment may cause otherwise normal structures to become new sources of nerve compression. Recurrent or persistent neuropathy after anterior transposition is commonly attributable to a new distal compression. The authors sought to clarify the anatomical relationship of the ulnar nerve to the common aponeurosis of the humeral head of the flexor carpi ulnaris (FCU) and flexor digitorum superficialis (FDS) muscles following anterior transposition of the nerve. METHODS: The intermuscular septa of the proximal forearm were explored in 26 fresh cadaveric specimens. The fibrous septa and common aponeurotic insertions of the flexor-pronator muscle mass were evaluated in relation to the ulnar nerve, with particular attention to the effect of transposition upon the nerve in this region. RESULTS: An intermuscular aponeurosis associated with the FCU and FDS muscles was present in all specimens. Transposition consistently resulted in angulation of the nerve during elbow flexion when this fascial septum was not released. The proximal site at which the nerve began to traverse this fascial structure was found to be an average of 3.9 cm (SD 0.7 cm) from the medial epicondyle. CONCLUSIONS: The common aponeurosis encountered between the FDS and FCU muscles represents a potential site of posttransposition entrapment, which may account for a subset of failed anterior transpositions. Exploration of this region with release of this structure is recommended to provide an unconstrained distal course for a transposed ulnar nerve.

Primary Neuritic Hansen's Disease presenting as Ulnar Nerve Abscess in a Human Immunodeficiency Virus Positive Patient.

Leprosy has been increasingly known to have an enigmatic relationship with human immunodeficiency virus infection. Co-infection may result in atypical manifestations of leprosy. A 45-year old human immunodeficiency virus-positive male; agricultural laborer presented with a swelling over right elbow, right hand deformity, generalized itching and recurrent vesicles overthe perinasal area. Clinical and investigational findings were consistent with mononeuritic type of Hansen's disease with right sided silent ulnar nerve abscess, partial claw hand. CD4+ count of the patientwas 430 cells/cmm. This patient also hadherpes simplex labialis, with HIV-associated pruritus. To the best of our knowledge such an atypical presentation has not been reported earlier.

Delayed-onset ulnar neuritis after release of elbow contractures: clinical presentation, pathological findings, and treatment.

BACKGROUND: Little information exists regarding delayed-onset ulnar neuritis (DOUN) after arthroscopic release of elbow contractures. PURPOSE: To describe, in a large cohort of patients, the clinical presentation of and risk factors for developing DOUN after arthroscopic release of elbow contractures. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A retrospective study of 565 consecutive arthroscopic releases of elbow contractures was conducted. Essentially, DOUN was defined as ulnar neuritis or neuropathy, or worsening of pre-existing ulnar nerve symptoms, that developed postoperatively in patients with normal neurological examination findings immediately after surgery. After inclusion and exclusion criteria were met, 235 contracture releases in patients who had not undergone any ulnar nerve surgery remained and were used for the analysis of risk factors with a multivariate logistic regression analysis. RESULTS: Twenty-six patients (11%) developed DOUN. The patients fell into 1 of 3 distinct groups. Fifteen (58%) presented with rapidly progressive DOUN, characterized by rapidly progressive sensorimotor ulnar neuropathy, increasing pain at the cubital tunnel during end-range flexion and/or extension, and rapidly deteriorating range of motion within the first week after surgery. Urgent ulnar subcutaneous nerve transposition was performed within 1 or 2 days of diagnosis. Eight (31%) presented with nonprogressive DOUN, characterized by mild sensory ulnar neuropathy, neither motor weakness nor substantial pain at the cubital tunnel, or loss of motion. Three (12%) presented with slowly progressive DOUN, characterized by the insidious onset of mild ulnar neuropathy. Significant risk factors for DOUN included a diagnosis of heterotopic ossification (odds ratio, 31; 95% CI, 5-191; P < .001), preoperative neurological symptoms (odds ratio, 6; 95% CI, 2-19; P = .001), and preoperative arc of motion (odds ratio, 0.97 per degree of motion; 95% CI, 0.96-0.99; P = .02). CONCLUSION: Delayed-onset ulnar neuritis is an important complication of arthroscopic release of elbow contractures. We recommend a high index of suspicion and monitoring patients with progressive loss of elbow motion and end-range pain for evidence of subclinical ulnar neuritis.