Ancient Schawanoma of radial nerve: a rare case report.

Soft tissue swellings on the forearm can present with a range of clinical and histopathological diagnosis. Ancient Schawanoma is a rare benign condition that can develop over the flexor surface of the forearm as a cystic swelling and can involve the median or the ulnar nerve. However, the presentation of this condition on the extensor surface with involvement of the radial nerve is an extremely uncommon diagnosis. A 69 year old female presented at the outpatient department with a swelling on the extensor aspect of her right forearm for the past 2 years. Ultrasound examination showed a mixed cystic solid mass and MRI report revealed a complex predominantly cystic mass in the extensor compartment of the forearm, measuring 4.3 x 5.3 x 7.2 cm size. After obtaining informed consent, the patient was operated under tourniquet control and the mass was removed sparing the radial nerve that was adherent to its capsule. The final histopathological report confirmed the diagnosis as Ancient Schawanoma.

A standardized ultrasound approach in neuralgic amyotrophy.

Neuralgic amyotrophy (NA), also referred to as idiopathic brachial plexitis and Parsonage-Turner syndrome, is a peripheral nerve disorder characterized by acute severe shoulder pain followed by progressive upper limb weakness and muscle atrophy. While NA is incompletely understood and often difficult to diagnose, early recognition may prevent unnecessary tests and interventions and, in some situations, allow for prompt treatment, which can potentially minimize adverse long-term sequalae. High-resolution ultrasound (HRUS) has become a valuable tool in the diagnosis and evaluation of NA. Pathologic HRUS findings can be grouped into four categories: nerve swelling, swelling with incomplete constriction, swelling with complete constriction, and fascicular entwinement, which may represent a continuum of pathologic processes. Certain ultrasound findings may help predict the likelihood of spontaneous recovery with conservative management versus the need for surgical intervention. We recommend relying heavily on history and physical examination to determine which nerves are clinically affected and should therefore be assessed by HRUS. The nerves most frequently affected by NA are the suprascapular, long thoracic, median and anterior interosseous nerve (AIN) branch, radial and posterior interosseous nerve (PIN) branch, axillary, spinal accessory, and musculocutaneous. When distal upper limb nerves are affected (AIN, PIN, superficial radial nerve), the lesion is almost always located in their respective fascicles within the parent nerve, proximal to its branching point. The purpose of this review is to describe a reproducible, standardized, ultrasonographic approach for evaluating suspected NA, and to share reliable techniques and clinical considerations when imaging commonly affected nerves.

Porphyric neuropathy.

Acute hepatic porphyrias are inherited metabolic disorders that may present with polyneuropathy, which if not diagnosed early can lead to quadriparesis, respiratory weakness, and death. Porphyric neuropathy is an acute to subacute motor predominant axonal neuropathy with a predilection for the upper extremities and usually preceded by a predominantly parasympathetic autonomic neuropathy. The rapid progression and associated dysautonomia mimic Guillain-Barré syndrome but are distinguished by the absence of cerebrospinal fluid albuminocytologic dissociation, progression beyond 4 wk, and associated abdominal pain. Spot urine test to assess the porphyrin precursors delta-aminolevulinic acid and porphobilinogen can provide a timely diagnosis during an acute attack. Timely treatment with intravenous heme, carbohydrate loading, and avoidance of porphyrinogenic medications can prevent further neurological morbidity and mortality.

Hourglass-Like Constriction Neuropathy of the Upper Limb Nerve: Diffusion-Weighted Magnetic Resonance Neurography Imaging Findings.

OBJECTIVE: The purposes of this study were to determine reliable diffusion-weighted magnetic resonance neurography (DW-MRN) features of hourglass-like constriction of the upper limb nerve and to evaluate the application value of DW-MRN compared with ultrasonography (US). METHODS: We retrospectively reviewed MRN studies of 13 patients. Qualitative and quantitative image analyses were carried out. The number of constrictions based on DW-MRN and US findings was compared. RESULTS: Of the 13 cases, there were 7 cases with radial nerve abnormalities, 4 with median nerve abnormalities, and 2 with radial and median nerve abnormalities. Diffusion-weighted MRN showed a single-segmental constriction in 7 of 13 cases and multisegmental constrictions in 6 of 13 cases; the hourglass-like constriction appeared in all cases (13 of 13). Thirty-three nerve constrictions were found in DW-MRN, and 29 nerve constrictions were found in US. CONCLUSIONS: Diffusion-weighted MRN is a noninvasive and helpful diagnostic for hourglass-like constriction of the upper limb nerve.

Leiomyoma of digit of hand: Report of three cases with literature review.

Leiomyoma is a benign tumor of smooth muscle origin most common in areas of the body with abundant smooth muscle including the gynecologic, genitourinary, and gastrointestinal system. Leiomyoma outside of these locations is believed to arise from vascular smooth muscle and arrector pili muscles. Leiomyoma of an extremity is a rare diagnosis, especially when present in a digit of the hand due to the paucity of smooth muscle in this location. We report three cases of leiomyoma of a digit of the hand.

Quantifying the Location of the Radial Nerve in Children for Intraoperative Use.

BACKGROUND: In adults, a relative "safe zone" for lateral approaches to the elbow has been well described in efforts to reduce iatrogenic injury, typically a minimum of 6 cm proximal to the lateral epicondyle. To avoid iatrogenic injury to the radial nerve intraoperatively, we investigated the distance of the nerve from the distal humeral physis in children. METHODS: All patients who had axial and coronal T1-weighted magnetic resonance imagings of the humerus and elbow between 2005 and 2015 were eligible. Patients were excluded if there was any pathology causing significant alteration to the normal anatomy of the distal humerus or surrounding soft tissue. The axial cut in which the radial nerve was positioned along a line passing through the center of the humerus in the transverse plane was identified, and the location of the nerve was marked. This axial cut was cross-referenced with the corresponding coronal view. The distance along the lateral edge of the humerus in a straight line from the marked location of the radial nerve to the distal humeral physis was measured. RESULTS: In total, 21 magnetic resonance imagings of 20 patients met the inclusion criteria. The mean distance of the radial nerve proximally from the distal humeral physis was as follows by age group: below 1-year old=1.7 cm (range, 1.2 to 2.5 cm); 1 to 2-years old=2.8 cm (range, 1.8 to 3.2 cm); 4 to 5-years old=5.3 cm (range, 5.1 to 5.5 cm); 6-years old and above=7.3 cm (range, 6.0 to 9.2 cm). For below 6-years old, when age was multiplied by 1 cm to define a predicted safe zone all radial nerves were found proximal to this. All patients 6 years and above had measurements that fell into the adult range of >6 cm, whereas no patients below 6-years old had measurements in this range. CONCLUSIONS: The distance of the radial nerve proximally from the distal humeral physis can be safely approximated for children below 6 years of age by multiplying patient age in years by 1 cm. By the age of 6 the distance of the radial nerve falls within the adult range (>6 cm). LEVEL OF EVIDENCE: Level III.

Ultrasonographic Evaluation of the Radial Nerves in Patients with Unilateral Refractory Lateral Epicondylitis.

Objective: To evaluate the possible radial nerve entrapment of patients with unilateral refractory lateral epicondylitis (LE) by using ultrasound (US) and electroneuromyography. Design: Cross-sectional study. Setting: Three physical medicine and rehabilitation departments. Subjects: Consecutive 44 patients (15 M, 29 F) with unilateral refractory LE. Methods: All patients underwent detailed clinical, electrophysiological and ultrasonographic evaluations. Ultrasound imaging was used to evaluate thickness and presence of abnormal findings of the common extensor tendon (CET) and cross-sectional area (CSA) of the radial nerve (at spiral groove and before bifurcation) bilaterally. Unaffected sides of the patients were taken as controls. Results: When compared with the unaffected sides, CET thickness and radial nerve CSAs (at both levels) were higher, and abnormal US findings regarding LE (47.7% vs. 6.8%) were more common on the affected sides than nonaffected sides (all P < 0.001). Grip strength values were lower on the affected sides ( P < 0.001). Electrophysiological studies were all normal, and similar between the two sides (all P > 0.05). When subgroup analyses were performed after taking into account the hand dominance, affected and dominant sides were found to be the same in 31 and different in 13 patients. In subgroups, CETs and radial nerve CSAs at both levels were higher on the affected sides (all P < 0.01). Conclusions: Radial nerves and the CETs seem to be swollen on the affected sides, independent from the hand dominance of the patients with refractory LE. These results morphologically support the previous literature that attributes some of the chronic complaints of these patients actually to radial nerve entrapment.

Nerve ultrasound identifies abnormalities in the posterior interosseous nerve in patients with proximal radial neuropathies.

INTRODUCTION: The radial nerve and posterior interosseous nerve (PIN) are prone to injury at multiple sites. Electrodiagnostic (EDx) studies may only identify the most proximal lesion. Nerve ultrasound could augment EDx by visualizing additional pathology. METHODS: This investigation was a retrospective examination of ultrasound and EDx from 26 patients evaluated for posterior cord/radial/PIN lesions. RESULTS: Eighteen of 26 patients had abnormalities on EDx (15 radial, 2 PIN, 1 posterior cord). Ultrasound identified 15 of 18 (83%) of the EDx abnormalities and provided additional diagnostic information. In 6 of 15 (40%) patients with EDx evidence of radial neuropathy, ultrasound identified both radial nerve enlargement and additional, unsuspected PIN enlargement (53% to 339% enlarged vs. unaffected side). Ultrasound also identified: nerve (dis)continuity at the trauma site (n = 8); and nerve tumor (n = 2; 1 with normal EDx). CONCLUSION: In radial neuropathy, ultrasound often augments EDx studies and identifies a second lesion in the PIN. Further studies are required to determine the etiology and significance of this additional distal pathology.

Causes of Secondary Radial Nerve Palsy and Results of Treatment.

BACKGROUND The aim of this study was to analyze the causes that lead to secondary damage of the radial nerve and to discuss the results of reconstructive treatment. MATERIAL AND METHODS The study group consisted of 33 patients treated for radial nerve palsy after humeral fractures. Patients were diagnosed based on clinical examinations, ultrasonography, electromyography, or nerve conduction velocity. During each operation, the location and type of nerve damage were analyzed. During the reconstructive treatment, neurolysis, direct neurorrhaphy, or reconstruction with a sural nerve graft was used. The outcomes were evaluated using the Medical Research Council (MRC) scales and the quick DASH score. RESULTS Secondary radial nerve palsy occurs after open reduction and internal fixation (ORIF) by plate, as well as by closed reduction and internal fixation (CRIF) by nail. In the case of ORIF, it most often occurs when the lateral approach is used, as in the case of CRIF with an insertion interlocking screws. The results of the surgical treatment were statistically significant and depended on the time between nerve injury and revision (reconstruction) surgery, type of damage to the radial nerve, surgery treatment, and type of fixation. Treatment results were not statistically significant, depending on the type of fracture or location of the nerve injury. CONCLUSIONS The potential risk of radial nerve neurotmesis justifies an operative intervention to treat neurological complications after a humeral fracture. Adequate surgical treatment in many of these cases allows for functional recovery of the radial nerve.

Surgical Anatomy of the Radial Nerve at the Elbow and in the Forearm: Anatomical Basis for Intraplexus Nerve Transfer to Reconstruct Thumb and Finger Extension in C7 - T1 Brachial Plexus Palsy.

Background C7 - T1 palsy results in complete loss of finger motion and poses a surgical challenge. This study investigated the anatomy of the radial nerve in the elbow and forearm and the feasibility of intraplexus nerve transfer to restore thumb and finger extension. Methods The radial nerves were dissected in 28 formalin-fixed upper extremities. Branching pattern, length, diameter, and number of myelinated fibers were recorded. Results Commonly, the branching pattern (from proximal to distal) was to the brachioradialis, extensor carpi radialis longus, superficial sensory proximal to the lateral epicondyle, extensor carpi radialis brevis, supinator, extensor digitorum communis, extensor digiti minimi, extensor carpi ulnaris, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, and extensor indicis distal to the lateral epicondyle. Conclusions Branches to the brachioradialis, extensor carpi radialis longus, and supinator can be transferred to the posterior interosseous nerve to restore hand movement in patients with C7 - T1 brachial plexus palsies; the supinator branch is probably the best choice in this regard.

Acute radial nerve entrapment at the spiral groove: detection by DTI-based neurography.

OBJECTIVES: This study evaluated the potential of three-tesla diffusion tensor imaging (DTI) and tractography to detect changes of the radial (RN) and median (MN) nerves during transient upper arm compression by a silicon ring tourniquet. METHODS: Axial T2-weighted and DTI sequences (b = 700 s/mm(2), 16 gradient encoding directions) of 13 healthy volunteers were obtained. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of the MN and RN were measured at the spiral groove and further visualized in 3D by deterministic tractography (thresholds: FA = .15, angle change = 27°). RESULTS: Local/lesional RN FA values increased (p = 0.001) and ADC values decreased (p = 0.02) during a 20-min upper arm compression, whereas no significant FA (p = 0.49) or ADC (p = 0.73) changes of the MN were detected. There were no T2-w nerve signal changes or alterations of nerve trajectories in 3D. CONCLUSIONS: Acute nerve compression of the RN leads to changes of its three-tesla DTI metrics. Peripheral nerve DTI provides non-invasive insights into the "selective" vulnerability of the RN at the spiral groove. KEY POINTS: • DTI-based neurography detects nerve changes during acute nerve compression. • Compression leads to a transient increase in local radial nerve FA values. • DTI provides insights into radial nerve vulnerability at the spiral groove.

Triple hourglass-like fascicular constriction of the posterior interosseous nerve: a rare cause of PIN syndrome.

Supinator syndrome or posterior interosseous nerve (PIN) syndrome is a compression neuropathy of the deep branch of the radial nerve in the region of the Arcade of Frohse. An extremely rare cause of an acute onset supinator syndrome is the hourglass-like fascicular constriction of the posterior interosseous nerve due to torsion. To our knowledge, only a limited number of cases which describe the sonographic appearance of fascicular torsions are known in the literature. We present a rare case of a supinator syndrome associated with hourglass-like constrictions of the PIN diagnosed by means of sonography.

Intraneural and perineural inflammatory changes in piglets after injection of ultrasound gel, endotoxin, 0.9% NaCl, or needle insertion without injection.

BACKGROUND: Ultrasound gel nerve inflammation has been reported. We evaluated the extent and nature of inflammation after gel injection with endotoxin (positive), saline, or dry needle puncture (negative) controls after peripheral blocks in piglets. METHODS: Selected nerves of 12 piglets were localized by landmarks and nerve stimulator. Forty-eight hours after injection, specimens were examined for immunohistochemical cell differentiation/quantification and cytokine expression by using quantitative polymerase chain reaction. RESULTS: Both gel and endotoxin injections resulted in a significantly higher density of inflammatory cells (lymphocytes/granulocytes) as compared with needle insertions and/or saline injections (both P < 0.001). Cytokines were not detected in any of the specimens. CONCLUSIONS: Perineural gel injections cause significant inflammation. The lack of cytokines suggests injectate-related changes rather than mechanical trauma.

Isolated radial nerve palsy in newborns--case report of a bilateral manifestation and literature review.

UNLABELLED: Uni- or bilateral radial nerve palsy in newborn is a rare symptom. We report about a case of unusual bilateral radial nerve palsy in a term-born girl who recovered completely after 10 months and review the English-speaking literature about this condition. Review of the literature shows less than 60 reported cases of radial nerve palsy, most of them unilateral. CONCLUSION: Besides the clinical examination, in most cases, no further diagnostic investigation is necessary. An incomplete restitution is rare as recovery mostly occurs within 3-6 months.

Intraneural Nodular Fasciitis of the Radial Nerve: A Case Report.

CASE: We report a case of intraneural nodular fasciitis in the forearm initially suspected as a schwannoma, emphasizing the importance of accurate diagnosis. A 40-year-old woman presented with mass on the lateral aspect of her right forearm and radial neuropathy symptoms for 2 months. An excisional biopsy and histopathological examination confirmed nodular fasciitis. Postoperative evaluation at 4.5 years found no pain, paralysis, or recurrence. CONCLUSION: Awareness of nodular fasciitis is crucial to prevent misdiagnosis and unnecessary treatment. Despite its rapid growth, nodular fasciitis generally has an excellent prognosis without long-term consequences.

Epithelioid sarcoma presenting as radial mononeuropathy: anatomical, magnetic resonance neurography and diffusion tensor imaging appearances.

The authors report an unusual case of radial mononeuropathy caused by epithelioid sarcoma and describe the anatomical 3-Tesla MR neurography and the functional diffusion tensor imaging findings of the case, which were subsequently confirmed on surgical excision and histopathology.

Macrodactyly in the setting of a plexiform schwannoma in neurofibromatosis type 2: case report.

Macrodactyly is a rare anomaly. Little is understood about the etiology and underlying mechanisms. To our knowledge, macrodactyly has not previously been associated with neurofibromatosis type 2. We present a case of macrodactyly of the small finger associated with a digital nerve plexiform schwannoma in a patient with neurofibromatosis type 2.