The radial sensory nerve entrapped between the two slips of a split brachioradialis tendon: a rare aspect of Wartenberg's syndrome

Radial nerve compression: anatomical perspective and clinical consequences

The radial nerve is the biggest branch of the posterior cord of the brachial plexus and one of its five terminal branches. Entrapment of the radial nerve at the elbow is the third most common compressive neuropathy of the upper limb after carpal tunnel and cubital tunnel syndromes. Because the incidence is relatively low and many agents can compress it along its whole course, entrapment of the radial nerve or its branches can pose a considerable clinical challenge. Several of these agents are related to normal or variant anatomy. The most common of the compressive neuropathies related to the radial nerve is the posterior interosseus nerve syndrome. Appropriate treatment requires familiarity with the anatomical traits influencing the presenting symptoms and the related prognoses. The aim of this study is to describe the compressive neuropathies of the radial nerve, emphasizing the anatomical perspective and highlighting the traps awaiting physicians evaluating these entrapments.

Split Brachioradialis Tendon Causing Wartenberg Syndrome in a Professional Baseball Pitcher

Wartenberg syndrome can occur when external factors compress the superficial radial nerve. It can also be due to anatomic variations, such as a split brachioradialis tendon entrapping the nerve. This case report describes a unique example of a professional baseball player diagnosed with Wartenberg syndrome who was later found to have a split brachioradialis tendon during surgical management. It is an important addition to the field of hand surgery since, to our knowledge, we have not identified such a rare case concerning a professional athlete previously described in the literature.

Approach to Diagnosis and Treatment of Dorsoradial Hand and Forearm Pain

Dorsoradial forearm and hand pain was historically considered difficult to treat surgically due to a particular susceptibility of the radial sensory nerve (RSN) to injury and/or compression. A nerve block, if it were done at all, was directed at the region of the anatomic snuff box to block the RSN in an effort to provide diagnostic information as to the pain etiology. Even for patients with pain relief following a diagnostic block, resecting the RSN often proved unsuccessful in fully relieving pain. The solution to successful treatment of this refractory pain problem was the realization that the RSN is not the sole source of sensory innervation to the dorsoradial wrist. In fact, in 75% of people the lateral antebrachial cutaneous nerve (LABCN) dermatome overlaps the RSN with other nerves, such as the dorsal ulnar cutaneous nerve and even the posterior antebrachial cutaneous nerves, occasionally providing sensory innervation to the same area. With this more refined understanding of the cutaneous neuroanatomy of the wrist, the diagnostic nerve block algorithm was expanded to include selective blockage of more than just the RSN. In contemporary practice, identification of the exact nerves responsible for pain signal generation informs surgical decision-making for palliative neurolysis or neurectomy. This approach offers a systematic and repeatable method to inform the diagnosis and treatment of dorsoradial forearm and wrist pain.

Superficial radial neuropathy: an unobserved etiology of chronic dorsoradial wrist pain

Background

Superficial radial neuropathy is considered an uncommon cause of chronic dorsoradial wrist pain. Its clinical diagnosis is usually missed. The purpose of the research was to investigate the existence of superficial radial neuropathy as a cause of chronic dorsoradial wrist pain. The study included 98 upper limbs obtained from 72 patients [58 women (80.6%)] with a primary complaint of chronic dorsoradial wrist pain and 91 asymptomatic upper limbs obtained from 63 apparently healthy individuals [46 women (73.0%)] as a control group. Clinical assessment and superficial radial nerve conduction study were done.

Results

No significant differences between patients and control group were present regarding sex and age. Among the participated patients, there were 29 upper limbs (29.6%) from 26 patients (36.1%) who had superficial radial neuropathy proved clinically and electrophysiologically. From them, three patients (11.5%) had bilateral superficial radial neuropathy. It was the solitary cause of chronic dorsoradial wrist pain in 15 upper limbs (51.7%) from 13 patients (50%). The remaining patients were associated with other musculoskeletal wrist conditions. The most common associated local wrist pathology was de Quervain’s disease in 8 upper limbs (27.6%) from 8 patients (30.8%).

Conclusions

Superficial radial neuropathy is common among patients with chronic dorsoradial wrist pain and should be considered in the differential diagnosis.

Robert Wartenberg Syndrome and Sign: A Review Article

Background:

Robert Wartenberg, a European-American neurologist, was born in 1887 and died in 1956. His description of radial sensory nerve compression at the forearm is memorialized as Wartenberg’s syndrome. He recognized that involuntary abduction of the little finger could be caused by ulnar nerve palsy - a finding often called Wartenberg’s sign Syndrome and signs are reviewed, and a brief biography is presented.

Objective:

To review Wartenberg’s sign and Wartenberg’s syndrome.

Discussion:

Compression of the superficial branch of the radial nerve, often called Wartenberg’s syndrome, is characterized by pain, paresthesia, and dysesthesia along the dorsoradial distal forearm. Non-operative treatment can include activity restriction and anti-inflammatory medication. If symptoms persist, surgical decompression of the radial nerve is an option. The abducted posture of the little finger - Wartenberg’s sign - can result from a low ulnar nerve palsy. Tendon transfer can be performed to correct this deformity.

Conclusion:

Compression of the superficial branch of the radial nerve and abducted posture of the little finger were described by Robert Wartenberg and carry his name as eponymous syndrome and sign, respectively.

Supernumerary brachioradialis - Anatomical variation with magnetic resonance imaging findings: A case report

BACKGROUND

In this single case report study, we describe an anatomical variance of a brachioradialis muscle with two muscle bellies and two tendons with their common insertion on the suprastyloid crest of a distal radius.

CASE SUMMARY

After a self-mutilating forearm injury of a borderline personality patient, we observed the anatomical variation of brachioradialis tendon. After tendon repair and aftercare the muscle function recovered completely. Five months after surgery the forearm magnetic resonance imaging was done revealing a supernumerary brachioradialis muscle.

CONCLUSION

Anatomical variations of forearm muscles and tendons are not rare. The treating surgeons should be aware of their existence and anatomical relationships.

Aberrant course of superficial radial nerve in the forearm: an anatomical variation and its clinical implications

The superficial radial nerve (SRN) is the terminal pure sensory branch of the radial nerve supplying dorsal aspects of the proximal portion of the lateral three and a half digits including the lateral two-thirds of the dorsum of the hand. It transits from its submuscular position to a subcutaneous position by passing between the brachioradialis and extensor carpi radialis longus tendons around 7 to 9 cm proximal to the radial styloid. We present a case where this nerve instead of its normal forearm course, pierced the brachioradialis tendon to become subcutaneous.

A case of a duplicated superficial branch of radial nerve and a two-bellied brachioradialis muscle presenting a potential entrapment syndrome

We have found an interesting coincidental variation of the superficial branch of the radial nerve and the brachioradialis muscle in a male cadaver. The superficial branch of the radial nerve was duplicated with one branch taking an aberrant course between two bellies of the brachioradialis muscle. The variant brachioradialis muscle featured two muscle bellies, a superficial one and a deep one, with one common origin and one common insertional tendon. The accessory nerve branch was impinged by two blood vessels and pierced through muscle bundles connecting two bellies of the brachioradialis muscle. The knowledge of this neuromuscular variant is of clinical relevance for the differential diagnosis of pain and paresthesia on the dorsoradial aspect of the hand and for the surgical management of the Wartenberg's syndrome.

Endoscopically assisted release of the superficial radial nerve

INTRODUCTION

The feasibility of endoscopically assisted decompression of the superficial radial nerve at the midportion and distal forearm was assessed.

SURGICAL TECHNIQUE

After a 3 cm longitudinal skin incision at the Tinel's sign at the forearm, the subcutaneous tissue is dissected until forearm fascia is detected. The fascia is opened cautiously under direct visualization and the superficial radial nerve is identified. Blunt forceps mobilize the subcutaneous tissue upon the fascia before the illuminated speculum is inserted. Then further dissection of the fascia is performed proximally using the Metzenbaum scissors. After further blunt tunneling by forceps the endoscope is introduced proximally in order to release the superficial radial nerve completely. Then the speculum is inserted distally to identify the nerve within the subcutaneous tissue. Then further visualization is facilitated using the endoscope.

CONCLUSION

The endoscopically assisted release of the superficial radial nerve may be feasible in a safe and sufficient way.

SUPERFICIAL BRANCH OF THE RADIAL NERVE PIERCING THE BRACHIORADIALIS TENDON TO BECOME SUBCUTANEOUS: AN ANATOMICAL VARIATION WITH CLINICAL RELEVANCE

We dissected 20 preserved Caucasian cadaveric upper limbs looking at the relation of the superficial branch of the radial nerve (SBRN) to the brachioradialis tendon. SBRN emerged from deep to superficial position by piercing the brachioradialis tendon near its dorsal border in four limbs. The resulting dorsal tendinous band compressed the nerve and prevented longitudinal gliding movement during ulnar flexion. This is likely to increase the risk of chronic compression neuropathy (Wartenberg's syndrome). In two of these four limbs, there was a communication between the SBRN and lateral cutaneous nerve of the forearm. No such communication was found in the remaining 16 forearms. This communication could contribute to the minimal area of sensory loss observed in Wartenberg's syndrome. We recommend that this anatomical anomaly is looked for and if present dealt with during surgical treatment of Wartenberg's syndrome, as it is likely to predispose to chronic compression neuropathy.

Performing arts medicine - instrumentalist musicians: part III - case histories

In parts I and II of this article series, the basic principles of examining musicians in a healthcare setting were reviewed [Dommerholt, J. Performing arts medicine - instrumentalist musicians: part I: general considerations. J. Bodyw. Mov. Ther., in press-a; Dommerholt, J. Performing arts medicine - instrumentalist musicians: part II: the examination. J. Bodyw. Mov. Ther., in press-b]. Part III describes three case reports of musicians with hand pain, interfering with their ability to play their instruments. The musicians consulted with a performing arts physiotherapist. Neither musician had a correct medical diagnosis if at all, when they first contacted the physiotherapist. Each musician required an individualized approach not only to establish the correct diagnosis, but also to develop a specific treatment program. The treatment programs included ergonomic interventions, manual therapy, trigger point therapy, and patient education. All musicians returned to playing their instruments without any residual pain or dysfunction.

THE SUPERFICIAL BRANCH OF THE RADIAL NERVE: A MORPHOLOGIC STUDY

Study the morphology of the superficial branch of the radial nerve (SBRN) of the forearms and wrists of fresh adult human cadavers. Methods: Twenty three dissections were performed under 3.5x loupe magnification, histological sections of the nerve were obtained in 20 dissections for fascicle identification. Results: The SBRN emerged, in average, at 8.65cm proximal to the radial styloid apophysis (RSA) between the Brachioradialis (BR) and Extensor Carpi Radialis Longus (ECRL) tendons. In 6/23 cases the SBRN emerged between an accessory BR tendon and the main BR tendon. The first branch of the SBRN arose at an average of 4.58 cm proximal to the RSA. A branch running across the RSA was found in 7/23 cases. At that level, the average number of branches crossing the wrist was 3.4. A fascicle count of the nerve and its first branch showed an average of 6.6 and 4.0 fascicles, respectively. Conclusion: Our anatomical findings are similar to those in the revised literature and contribute towards a better knowledge of the SBRN. Great caution is required in surgical procedures such as percutaneous bone fixation of the distal 1/3 of the forearm and wrist and particularly, in those susceptible to SBRN injury, as in seven of the 23 cases the SRBN ran directly accross the RSA. The authors recommend performing small longitudinal incisions down to the subcutaneous tissue, separating the nerve branches by blunt soft tissue dissection, with a delicate haemostat, before introducing the Kirschner wires (minimally invasive procedures).

Neurolysis of the distal superficial radial nerve for dysaesthesia due to nerve tethering

The subcutaneous course of the superficial radial nerve over the radial border of the wrist and hand renders it very susceptible to injury. Both traumatic and iatrogenic injury can produce tethering of this nerve, presenting as dysaesthesia. This study was designed to evaluate the efficacy of neurolysis of the distal superficial radial nerve for this condition. Twenty-five cases of tethered superficial radial nerves underwent neurolysis. At final follow-up (mean 3.5 years), fourteen cases reported symptomatic resolution while eleven continued to experience dysaesthesia. Intra-operatively, evidence of external abnormality, scarring, or compression was identified in only six cases, and its presence did not correlate with symptomatic outcome. Although the majority of patients were improved postoperatively, the success rate was lower than anticipated. Therefore, while neurolysis of the superficial radial nerve offers the opportunity for pain relief, it does not reliably produce success.

Entrapment of the sensory branch of the radial nerve (Wartenberg's syndrome): an unusual cause

Isolated neuropathy of the cutaneous branch of the radial nerve is a rarely recognized pathology. It was described in 1932 by Wartenberg, who suggested the name cheiralgia paraesthetica. The syndrome is described as known the entrapment of the superficial branch of the radial nerve. Many different etiologic factors for chronic nerve entrapment have been described, however our case has an unusual cause. A 52 year old man had pain and paresthesia in the area over the lateral aspect of the wrist, thumb and first web six months after Colles' fracture. The patient underwent bony spike resection after five months with ineffective conservative treatment. He has satisfied after this operation. The case was presented because of disappearing his preoperative complaints after the operation with respect to Wartenberg's syndrome constituted a rare cause of bone spike which has not been mentioned in the literature.

Upper extremity peripheral nerve anatomy: current concepts and applications

The nerve anatomy of the upper extremity is studied constantly through surgical findings, electrodiagnostic studies, and cadaveric dissections. Although it is recognized that the anatomy is not changing rapidly, knowledge of the anatomic relationships and their significance is increasing. The purpose of the current study is to provide a comprehensive analysis of the nerve anatomy of the upper extremity to include innervation patterns, critical landmarks, and clinical applications, with particular focus on recent contributions in the literature.

Radial neuropathy

The radial nerve is the largest branch of the brachial plexus, and is commonly involved in upper extremity mononeuropathies. The radial nerve is primarily responsible for motor innervation of the upper extremity extensors, as well as receiving cutaneous innervation from most of the posterior arm, forearm, and hand. There are a variety of sites at which the radial nerve is susceptible to trauma and entrapment. Localizing radial nerve lesions is dependent on clinical knowledge of radial nerve anatomy, and sensory and motor examination.