Radial Nerve Palsy Caused by Desmoid-Type Fibromatosis: A Case Report and Review of the Literature.

Radial nerve palsy (RNP) is classified as traumatic, non-traumatic, or iatrogenic. The most frequent etiologic agent is the fracture of the humerus of the shaftand distal. We experienced a case of RNP caused by desmoid-type fibromatosis around the radial nerve. The RNP caused by desmoid-type fibromatosis has not been reported in the literature. We present this case here with a review of the RNP literature. The patient is a 16-year-old female, right-hand dominant, who became aware of the difficulty in extending her right little finger without any triggers five months ago. She was also aware of the difficulty in extending the ring finger, and her symptoms gradually worsened. She was referred to our hospital after consulting a home doctor. MRI of the elbow showed a high-intensity occupying lesion on T2-weighted images (T2WI) slightly proximal to the elbow joint. Ultrasonography (US) showed a partial nerve constriction and radial nerve enlargement on the distal side of the constriction. The approach was made from the posterior lateral side of the distal upper arm, and the radial nerve was exposed. There was a 1 cm white tissue strongly adherent on the radial nerve, which was compressing the radial nerve, and it was resected piece by piece. After the resection, the radial nerve was indented. The pathological diagnosis of the resected tissue was fibromatosis. Gradually, she was able to extend her fingers after the surgery and recovered completely in six months.

The accessory brachioradialis muscle: prevalence of a rare variant with possible clinical implications.

PURPOSE: The brachioradialis muscle (BRM) belongs to the lateral group of forearm muscles and contributes to the elbow flexion. Accessory brachioradialis muscle (ABRM) or "brachioradialis accessorius" represents an uncommon BRM variant, not been enough studied. The present study investigates the prevalence of the ABRM, along with its origin, insertion, and innervation. MATERIALS: Eighty-three upper limbs were meticulously dissected at the arm, forearm, and cubital fossa to investigate the ABRM presence. When the variant muscle was identified, morphometric measurements were obtained. RESULTS: The ABRM was identified in two upper limbs (2/83, 2.4%), in a male cadaver, bilaterally. Its origin was located along with the typical BRM, and its insertion was identified into the anterior surface of the radius (proximal third). The ABRM was innervated by the radial nerve, coursing posteriorly (deeply). CONCLUSIONS: In the current study, the variant muscle was observed in 2.4%. Radial nerve compression, at the forearm, is not an uncommon entrapment neuropathy. The relationship between the radial nerve and the ABRM could precipitate radial neuropathy.

Linear morphea distributed along radial nerve with high incidence of neuromusculoskeletal disorders: A single-center case series.

Linear morphea is the most disabling subtype of morphea, which may cause a series of excutaneous manifestations and sequelae. To futher explore the clinical characteristics of linear morphea, we conducted a retrospective study of 22 patients diagnosed with linear morphea in our department during the past 2 years. Their baseline clinical information, skin manifestations, complications and therapeutic effect were analyzed. Here, we report six cases of a special linear morphea, usually occurring on the unilateral upper limbs of young women, spreading along the distribution of the radial nerve and frequently progressing across the joint, which increases the incidence of neuromusculoskeletal disorders. Instead of traditional topical drugs, a combination of systemic prednisone and methotrexate improved their skin lesions and complications. Recognition of this special type of linear morphea enables earlier diagnosis and active treatment plan, which contributes to ameliorate the symptoms and avoid functional sequelae.

Hourglass-like constrictions of the radial nerve in the neuralgic amyotrophy: A case report.

Neuralgic amyotrophy (NA) is a peripheral nerve disorder that has a classical presentation as motor deficit after severe pain, but it is still overlooked or misdiagnosed. Formerly, the diagnosis was based on the clinical picture and electrophysiology; however, sophisticated imaging and surgical modalities showed structural abnormalities such as hourglass-like constrictions of the nerves. In this article, we present a case presenting with drop hand mimicking radial nerve entrapment. The patient was diagnosed with NA and surgery revealed hourglass-like constrictions. The clinical findings were improved after neurorrhaphy and physical therapy. In conclusion, hourglass-like constrictions can be prognostic factors of NA and should be searched carefully.

Cords of the Brachial Plexus and Their Branches Positioned Laterally to the Axillary Artery.

The brachial plexus, which supplies the upper limb, extends from the interscalene triangle in the root of the neck to the axilla and is closely related to the subclavian and axillary arteries. Variations in the formation, branching pattern, and relations are profound, and it is generally stated that variant anatomy of the plexus appears to be a rule rather than an exception. In previous studies, it was hypothesized that the anomalous development of the subclavian-axillary stem and the persistence of intersegmental arteries could induce variations in the plexus. In this study, all three cords of the brachial plexus (lateral, medial, and posterior) and their terminal branches are consistently found lateral to the third part of the axillary artery. Most of the studies reported variation in one or the other cord or its branches, but very few studies have reported about all cords lateral to the brachial plexus. The brachial plexus variations are usually also associated with the variations in the branches of the axillary artery, but in this study, no such variation is noted in the branches of the axillary artery. These differences impact the methods of surgery and the application of regional anesthesia. For successful outcomes, it is important to know how neurovascular relationships work, such as where the cords are in relation to the axillary artery. We report an interesting case of all cords and their branches positioned lateral to the axillary artery in the axilla in an adult male cadaver.

Posterior Interosseous Nerve Syndrome due to Schwannoma - A Case Report.

Posterior interosseous nerve syndrome is the most frequent syndrome of radial nerve compression, with the arcade of Frohse being the main site of compression. Its symptoms include difficulties in finger and wrist extension with possible radial deviation. Herein, we present a case of posterior interosseous syndrome caused by a schwannoma, a type of neurological tumor.

Ultrasound-Based Multi-Planar Bilateral Comparisons as a Diagnostic and Treatment-Definition Method for Unilateral Peripheral Nerve Entrapment.

OBJECTIVE: The primary goal was to determine the performance of the cross-section area swelling rate (CSASR) for diagnostic and therapeutic purposes based on the reference standard of electrodiagnosis examination (EDX) in this diagnostic test study. METHODS: First, patients with symptoms like unilateral carpal tunnel syndrome (CTS), cubital tunnel syndrome (CuTS), and radial nerve compression (RNC) underwent EDX and ultrasound examination. Second, patients with positive ultrasound were calculated for the CSASR of diseased nerve. Based on previously established CSASR criteria, each patient was categorized as having or not having peripheral nerve entrapment, and for those meeting diagnostic criteria, non-surgical or surgical treatment was recommended. Then, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy rate (ACC) of ultrasound diagnosis and therapeutic decision-making were calculated based on the reference standard of EDX that had been historically used in the practice. RESULTS: The total sensitivity, specificity, PPV, NPV, and ACC of ultrasound diagnosis are respectively 93.4, 85.2, 94.7, 82.1, and 91.3%. Which of therapeutic decision-making by ultrasound are, respectively, 83.3, 52.2, 78.4, 60.0, and 73.2%. CONCLUSION: The sensitivity and Youden's index of CSASR diagnostic threshold for CuTS is higher than other ultrasound methods. The CSASR diagnostic threshold for CuTS has a potential diagnostic role, but the current date is still not enough to support the potential diagnostic role for CTS or RNS. There is insufficient evidence to suggest that CSASR for CuTS can be used in isolation for diagnosis. Additional research is needed to confirm the diagnostic role of CSASR. The current results suggest that this ultrasound examination method is not suitable for therapeutic decision-making.

Enhanced nerve function recovery in radial nerve palsy patients with humerus shaft fracture: a randomized study of low-frequency pulse electrical stimulation combined with exercise therapy.

Objective: To evaluate the effect of low-frequency pulse electrical stimulation plus exercise therapy on nerve function recovery in patients with radial nerve palsy after humerus shaft fracture. Methods: A total of 110 patients with humerus shaft fracture and radial nerve injury admitted to our hospital from January 2017 to December 2021 were recruited. They were randomized to receive either conventional exercise therapy (control group) or conventional exercise therapy plus low-frequency pulse electrical stimulation (study group) according to the random number table method, with 55 cases in each. Clinical efficacy, muscle strength recovery, nerve conduction velocity (MCV), amplitude, wrist joint, and elbow joint activities of patients were analyzed and compared. Results: Patients with low frequency stimulation (LFS) showed significantly higher treatment effectiveness (89.09%) than those with exercise therapy only (69.09%). The incorporation of LFS with exercise therapy provided more enhancement in the muscle strength of wrist extensor and total finger extensor in patients when compared with a mere exercise intervention, suggesting better muscle function recovery of patients produced by LFS. Moreover, a significant increase in MCV and its amplitude was observed in all included patients, among which those receiving LFS showed a greater escalation of MCV and its amplitude. Following a treatment duration of 6 months, more patients in the LFS cohort were reported to achieve a wrist extension and elbow extension with an angle over 45° than the controls. There was no notable variance in adverse responses noted between the two patient groups. Conclusion: In patients afflicted with humerus shaft fracture and radial nerve injury, the amalgamation of exercise therapy with low-frequency pulse electrical stimulation can significantly improve clinical efficacy, promote nerve function, and muscle strength recovery, and features a high safety profile. Relevance to clinical practice: The combination of exercise therapy and low-frequency pulsed electrical stimulation can notably improve the promotion of neurologic function and muscle strength recovery in patients with humerus shaft fractures and radial nerve injuries with a high degree of safety.Clinical trial registration:https://www.researchregistry.com, identifier researchregistry9461.

Radial and median nerves distal peripheral tension after reverse shoulder arthroplasty: a cadaveric study.

Background: Peripheral nerve injury is a recognized complication after reverse shoulder arthroplasty (RSA) that has mainly been studied at the level of the brachial plexus and its proximal branches. However, the impact of RSA on distal peripheral nerves and the influence of elbow and wrist position is not known. This cadaveric study aimed to analyze the effect of RSA implantation and upper limb position on tension in the distal median and radial nerves. The hypothesis was that RSA increased distal nerve tension, which could be further affected by elbow and wrist position. Methods: 12 upper limbs in 9 full fresh-frozen cadavers were dissected. Nerve tension was measured in the median nerve at the level of the proximal arm, elbow, and distal forearm, and in the radial nerve at the level of the elbow, using a customized three-point tensiometer. Measurements were carried out before and after RSA implantation, using a semi-inlay implant (Medacta, Castel San Pietro, Switzerland). Two different configurations were tested, using the smallest and largest available implant sizes. Three upper-limb key positions were considered (plexus at risk, plexus relief, and neutral), from which the effect of elbow and wrist position was further tested. Results: RSA implantation significantly increased median and radial nerve tension throughout the upper limb. The distal nerve segments were particularly dependent on elbow and wrist position. The plexus at risk position induced the most tension in all nerve segments, especially with the large implant configuration. On the other hand, the plexus relief position induced the least amount of tension. Flexing the elbow was the most efficient way to decrease nerve tension in all tested nerve segments and key positions. Wrist flexion significantly decreased nerve tension in the median nerve, whereas wrist extension decreased tension in the radial nerve. Conclusion: RSA significantly increases tension in the median and radial nerves and makes them more susceptible to wrist and elbow positioning. The mechanism behind distal peripheral neuropathy after RSA may thus result from increased compression of tensioned nerves against anatomical fulcrums rather than nerve elongation alone. Elbow flexion was the most effective way to decrease nerve tension, while elbow extension should be avoided when implanting the humeral component. Further studies are needed to assess the ulnar nerve.

Ultrasound-guided localization of the radial nerve along the humerus: providing reference points for safer upper arm surgery.

PURPOSE: The close proximity of the radial nerve to the humerus poses a risk during upper arm surgery. Although the general course of the radial nerve is well-known, its exact position in relation to anatomical reference points remains poorly investigated. This study aimed to develop a standardized protocol for the sonographic and clinical identification of the radial nerve in the upper arm. The ultimate goal is to assist surgeons in avoiding iatrogenic radial nerve palsy. METHODS: A total of 76 measurements were performed in 38 volunteers (both sides). Ultrasound measurements were performed using a linear transducer (10 MHz) to identify the radial nerve at two key points: RD (where the radial nerve crosses the dorsal surface of the humerus) and RL (where the radial nerve crosses the lateral aspect of the humerus). Distances from specific reference points (acromion, lateral epicondyle, medial epicondyle, olecranon fossa) to RD and RL were measured, and the angle between the course of the nerve and the humeral axis was recorded. Humeral length was defined as the distance between the posterodorsal corner of the acromion and the lateral epicondyle. RESULTS: The distance from the lateral epicondyle to RD was on average 15.5 cm ± 1.3, corresponding to 50% of the humeral length. The distance from the lateral epicondyle to RL was on average 6.7 cm ± 0.8, corresponding to 21% of the humeral length. The course of the nerve between RD and RL showed an average angulation of 37° to the anatomical axis of the humerus. Gender, BMI, dominant hand, and arm thickness did not correlate with the distances to RD or RL. Measurements were consistent between the left and right side. CONCLUSION: The radial nerve can typically be identified by employing a 1/2 and 1/5 ratio on the dorsal and lateral aspects of the humerus. Due to slight variations in individual anatomy, the utilization of ultrasound-assisted visualization presents a valuable and straightforward approach to mitigate the risk of iatrogenic radial nerve palsy during upper arm surgery. This study introduces an easy and fast protocol for this purpose.

Results of Tendon Transfers in Radial Nerve Palsies: A New Evaluation Protocol.

Radial nerve palsies present a challenging clinical scenario, often leading to substantial functional impairment. This study focuses on evaluating the outcomes of tendon transfer surgeries in patients with post-traumatic radial nerve injuries. The radial nerve, vital for upper limb movements, faces various etiologies, such as trauma, compression, or idiopathy. Patients with radial nerve palsy encounter difficulties in daily activities, emphasizing the need for effective management strategies. The research introduces a novel evaluation protocol, aiming to comprehensively assess tendon transfer outcomes. This protocol incorporates functional movements of wrist and finger joints, encompassing both objective and subjective parameters. The retrospective study includes eleven patients treated between 2010 and 2022, with a minimum follow-up of one year post-surgery. Tendon transfers demonstrated positive results. The evaluation protocol covers a wide range of parameters, including wrist and finger mobility, thumb function, grip strength, and patient satisfaction. The results indicate successful restoration of motor function, with an average grip strength of 70% compared to the healthy arm. The proposed evaluation protocol facilitates standardized and reproducible assessment, minimizing subjective errors in clinical evaluations. Despite the study's limitations, such as a relatively small sample size, the findings underscore the effectiveness of tendon transfers in treating radial nerve palsies. The introduced evaluation scheme provides a comprehensive and reproducible approach to assess outcomes, contributing to the global standardization of tendon transfer assessments in radial nerve injuries.

Neurovascular crossing patterns between leash of Henry and deep branch of radial nerve: implications for neurointervention and diagnostic imaging.

OBJECTIVE: To detail the neurovascular crossing patterns between the leash of Henry (LoH) and the deep branch of the radial nerve (DBRN) in supination and pronation of the forearm, using imaging methods with anatomic correlation. MATERIALS AND METHODS: This cross-sectional study was performed ex vivo with HRUS and MRI with anatomic correlation on 6 samples and in vivo with HRUS with Doppler on 55 participants scanned bilaterally. The in vivo participants were enrolled over a 6-month period. The crossing patterns between the LoH and DBRN were assessed ex vivo and in vivo. Additional morphological features of the DBRN, LoH, and fat plane were assessed in vivo only. Biometric features of the participants were recorded. Statistical analyses were performed using Shapiro-Wilk, parametric and non-parametric tests. RESULTS: The most common neurovascular crossing pattern was the ascending branch of the radial recurrent artery (RRAab) crossing below (ex vivo: 83.3%, in vivo: 85.3%) and the muscular branch crossing above (ex vivo: 100%, in vivo: 63.2% %) the DBRN. Both the deep and superficial surfaces of the DBRN exhibited an intimate relationship with the vessels of the LoH. A positive correlation between vessel diameter and anthropometric factors was observed. In addition, the muscular branch exhibited a significantly smaller diameter than the RRAab. CONCLUSION: Our study detailed the relationship between the LoH and the DBRN and highlighted the high incidence of vessel crossing above the DBRN at the level of the muscular branch. Knowledge of neurovascular crossings is crucial for understanding neurovascular entrapment syndromes and planning interventional procedures to reduce vascular complications.

Anatomical analysis of the radial nerve and arcade of Frohse in the cubital fossa using human cadavers.

BACKGROUND: The radial nerve (RN) is a peripheral nerve that originates from the posterior bundle of the brachial plexus and carries C5-Th1 fibers. In the cubital fossa radial nerve divides into a superficial branch of the radial nerve (SBRN) and a deep branch of the radial nerve (DBRN). Next DBRN enters under the arcade of Frohse (AF) and changes its name to posterior interosseous nerve of antebrachii (PIN). The AF was first described in 1908 by Frohs and Frankel. It is the superior proximal part of the supinator muscle, which can be tendinous or membranous. MATERIALS AND METHODS: Eight dissected upper limbs were examined to measure the distances and characteristics of the RN, DBRN, SBRN and AF, utilizing precise electronic caliper. RESULTS: The average distance from the point of branching of the RN into its terminal branches to the AF was 54.64 mm on average. In half of the cases DBRN divided before entering the AF. The average distance from the point of branching of the DBRN to the AF in these cases was 13.88 mm. The width of the AF averaged 8.60 mm. Five tendinous AF and three membranous AF were identified. CONCLUSIONS: A thorough understanding of the anatomy of the radial nerve and its branches in the cubital fossa, as well as the AF, is important for the development of anatomy and may also contribute to the reduction of surgical complications during procedures in this area.

Complete encasement of the radial nerve by a giant lipoma: illustrative case.

BACKGROUND: Among the spectrum of adipose lesions associated with peripheral nerves, complete circumferential encasement of the nerve by the lesion is a very rare entity. The authors report the first case of a giant lipoma that completely and circumferentially encased the radial nerve. OBSERVATIONS: A 57-year-old woman presented with a large left-arm mass that she had noticed over a year following significant weight loss. She had hypersensitivity and dysesthesias in the left posterior arm but no weakness or other symptoms. Magnetic resonance imaging of the left upper limb demonstrated a large lipoma completely encasing the radial nerve, originating at the level of the spiral grove proximally and extending distally to the lateral epicondyle. The lesion was completely resected at surgery with total preservation of radial nerve function. LESSONS: Lipomas encasing peripheral nerves can be difficult to manage while preserving function. This case adds to the intriguing spectrum of adipose lesions associated with peripheral nerves. https://thejns.org/doi/10.3171/CASE24148.

Superficial thrombophlebitis in the forearm leading to entrapment of the radial nerve branch: a first case report and literature review.

This article reports a case of a female patient admitted with swelling and subcutaneous mass in the right forearm, initially suspected to be multiple nerve fibroma. However, through preoperative imaging and surgery, the final diagnosis confirmed superficial thrombophlebitis. This condition resulted in entrapment of the radial nerve branch, leading to noticeable nerve entrapment and radiating pain. The surgery involved the excision of inflammatory tissue and thrombus, ligation of the cephalic vein, and complete release of the radial nerve branch. Postoperative pathology confirmed the presence of Superficial Thrombophlebitis. Through this case, we emphasize the importance of comprehensive utilization of clinical, imaging, and surgical interventions for more accurate diagnosis and treatment. This is the first clinical report of radial nerve branch entrapment due to superficial thrombophlebitis.

Nomenclature of the radial nerve: distinguishing between the deep branch of the radial nerve and the posterior interosseous nerve.

To address an inconsistency in the nomenclature of the anatomy and compressive syndromes of the deep branch of the radial nerve, we advocate for a single compression syndrome that presents along a spectrum from pain to posterior interosseous nerve palsy.

Motor Branching Pattern of the Radial Nerve for Hyperselective Neurectomy: From Anatomy to Clinical Translation.

PURPOSE: Predominant or isolated spasticity of the triceps following upper motor neuron injury is rare and often unmasked once the spastic elbow flexors are addressed. The purpose of this study was to delineate the motor branching pattern of the radial nerve to determine the feasibility of hyperselective neurectomies (HSN) for triceps spasticity. METHODS: Dissections of the motor branch to each triceps head were performed on 11 upper-extremity specimens. The numbers of trunks, branching patterns, and muscle entry points were recorded in reference to the acromion to interepicondylar line. Based on anatomic studies, 10 patients underwent a combined fractional lengthening and HSN procedure for triceps spasticity. Patient demographics, time from diagnosis, and complications were recorded. Preoperative and postoperative Modified Ashworth Scale (MAS) and total active elbow arc of motion were compared. RESULTS: The first branch from the radial nerve was consistently a single trunk to the long triceps head. There were many variations in the branching pattern and number of trunks to the lateral and medial heads of the triceps with motor entry points between 31% and 95% of the acromion to interepicondylar line distance. Ten patients (six men and four women; mean age: 48.5 years) underwent the combined procedure. Mean total active elbow arc of motion improved from 78° before surgery to 111° after surgery, with a 17.5° increase in active elbow flexion. Compared with a mean preoperative triceps MAS of 2.75, nine patients had triceps MAS of 0 at a mean of 10.2 months of follow-up. There was no loss of functional elbow extension and no directly related complications. CONCLUSIONS: Given the variable motor entry points, HSN to each triceps head would require extensive dissection. Therefore, a combined approach consisting of fractional lengthening of the long head and lateral head with HSN of the triceps medial head is recommended to address triceps spasticity. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Peripheral nerve injuries associated with dislocated supracondylar fractures of distal humerus in children: incidence and need of surgical treatment.

PURPOSE: The objective of this study was to determine the incidence, necessity for neurosurgical intervention, and overall results of the treatment of pediatric peripheral nerve injuries associated with dislocated supracondylar fractures of the distal humerus. METHOD: A retrospective analysis of pediatric patients with supracondylar fractures treated from April 2019 to April 2022 with a minimum follow-up of 3 months was conducted. RESULTS: Of 453 included patients, there were 51 recorded peripheral nerve injuries. The ulnar nerve was the most frequently injured nerve. Nine patients required neurosurgical intervention, with the most common procedure being the release of entrapped nerves. The combination of a supracondylar fracture and arterial injury was identified as a significant risk factor for peripheral nerve injury (p < 0.001). Only one patient experienced an unsatisfactory outcome. CONCLUSION: Although the prognosis for peripheral nerve injuries in children with supracondylar fractures is generally favorable, these injuries must be properly identified. We recommend an active neurosurgical approach in children with persisting neurological deficits to minimize the risk of permanent neurological impairment.