Radial Nerve Compression Research Articles

Special issue: nerve compression syndromes "Brachioradialis, or "High Wartenberg", syndrome - compression of the sensory branch of the radial nerve in the proximal forearm.

Compression of the sensory branch of the radial nerve (SBRN) in the proximal forearm is an uncommon condition, leading to both motor and sensory deficits. The aim of this study is to assess the surgical outcomes of SBRN release at the level of the brachioradialis arcade. A retrospective study of prospectively collected data was conducted on patients undergoing brachioradialis release (BRR) from March 2014 to March 2021. The measured outcomes included quick-DASH (Disability of the Arm Shoulder Hand questionnaire), work-DASH, visual analog scale (VAS) scores for pain, and patient satisfaction with surgery, at a minimumsixmonth follow-up. A total of twenty patients (mean age of 44.1 (range 25-62) were included in this study, of whichnine (45%) were males. Eleven patients (55%) underwent isolated BRR, while the other nine patients (45%) underwent concomitant BRR and lacertus release. The three most common presenting symptoms in patients with isolated BRS were radiovolar forearm pain (100%), disturbed sensation in the SBRN territory (85%), and hand/thumb fatigue (75%). Forearm pain and fatigue were found in all patients with combined BRS and lacertus syndrome. The response rate for the functional outcome scores was 65% (13/20). Quick-DASH significantly improved (preoperative 29.6 (range 13.6-57.5) to postoperative 6.9 (range 0-27.27), p < 0.0001) as did the work DASH (p < 0.0001). Follow-up VAS Pain was 1 and satisfaction with surgery 9.6. BRS is an uncommon radial nerve compression syndrome in the proximal forearm that differs from the more commonly recognized radial tunnel syndrome. It presents with radio-volar forearm pain, disturbed sensation in the SBRN distribution, and loss of hand/thumb endurance. Minimally invasive BRR immediately restores wrist extension strength, significantly improves DASH scores, and yields positive outcomes at a minimum six-month follow-up.

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

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. 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. 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). 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.

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

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. 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. 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%. 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.

Assessing the Influence of Nonischemic A-Fiber Conduction Blockade on Offset Analgesia: An Experimental Study

Offset analgesia (OA) is believed to reflect the efficiency of the endogenous pain modulatory system. However, the underlying mechanisms are still being debated. Previous research suggested both, central and peripheral mechanisms, with the latter involving the influence of specific A-delta-fibers. Therefore, this study aimed to investigate the influence of a nonischemic A-fiber conduction blockade on the OA response in healthy participants. A total of 52 participants were recruited for an A-fiber conduction blockade via compression of the superficial radial nerve. To monitor fiber-specific peripheral nerve conduction capacity, quantitative sensory testing was performed continuously. Before, during, and after the A-fiber block, an individualized OA paradigm was applied to the dorsum of both hands (blocked and control sides were randomized). The pain intensity of each heat stimulus was evaluated by an electronic visual analog scale. A successful A-fiber conduction blockade was achieved in thirty participants. OA has been verified within time (before, during, and after blockade) and condition (blocked and control side) (P < .01, d > .5). Repeated measurements analysis of variance showed no significant interaction effects between OA within condition and time (P = .24, η²p = .05). Hence, no significant effect of A-fiber blockade was detected on OA during noxious heat stimulation. The results suggest that peripheral A-fiber afferents may play a minor role in OA compared with alternative central mechanisms or other fibers. However, further studies are needed to substantiate a central rather than peripheral influence on OA. PerspectiveThis article presents the observation of OA before, during, and after a successful A-fiber conduction blockade in healthy volunteers. A better understanding of the mechanisms of OA and endogenous pain modulation, in general, may help to explain the underlying aspects of pain disorders.

Acute abdomen syndrome and radial nerve compression correlated with diffuse metastatic melanoma in the lymphatic system and skeletal muscle: case report

Acute abdomen syndrome and radial nerve compression correlated with diffuse metastatic melanoma in the lymphatic system and skeletal muscle: case report

Wartenberg’s syndrome – A unique presentation resulting from compression of the superficial radial nerve from an anomalous radial artery branch

Wartenberg’s syndrome is a compression sensorineural mononeuropathy of the superficial branch of the radial nerve. This case report describes a patient, who was severely debilitated by compression of the superficial branch of the radial nerve that she was unable to work. The case highlights a unique anatomical variation in the course of the deep terminal branch of the superficial radial artery causing compression of the superficial branch of the radial nerve. To the best of our knowledge, this has never been described before and should be considered a rare cause of Wartenberg’s syndrome. Surgery can provide both diagnostic and therapeutic benefits and should be considered early in such cases, especially when investigations are contradictory.

Radial tunnel syndrome-diagnosis and treatment

Radial tunnel syndrome is defined as intermittent compression of the deep branch of the radial nerve through the borders of the radial tunnel. This is one of the diagnosis in the spectrum of the causes for lateral elbow pain. The condition is associated with pain in the area of radial nerve compression which is located in most of the cases at the entrance of the nerve in the arcade of Frohse. The clinical examination is of utmost importance for determination of the diagnosis. . The standard static electromyography can’t record the intermittent compression of the nerve and it is not sensitive for the injury of the unmyelinated fibers (C-type) which is the main source of the pain. The goals of the treatment of RTS are to eliminate the pain and to encourage the patients to return to their routine activities. A trial of nonsurgical treatment is warrant in all the patients. In the cases with no respond to the conservative methods we advocate for surgical decompression of the nerve.

Pronator Quadratus: A Preferable Recipient for Targeted Muscle Reinnervation of Neuromas in the Hand.

Targeted muscle reinnervation (TMR) has emerged as a useful solution to the problem of painful neuromas and is increasingly being applied in many clinical circumstances. Relatively little has been written about TMR for painful neuromas of the hand, and what has been written describes use of the intrinsic muscles as recipients for the nerve transfer. Except in cases of amputation, intrinsic muscle sacrifice carries morbidity. Furthermore, TMR to intrinsic muscles will place the nerve coaptation in areas subject to pressure with loading of the palm. For these reasons, the pronator quadratus may be a preferable target muscle when performing TMR for painful neuromas of the hand. In this report, we describe the rationale for its use and demonstrate the surgical technique and outcomes with case examples.

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.

Some Misconceptions in the Treatment of Cubital Tunnel Syndrome, Radial Tunnel Syndrome, and Median Nerve Compression in the Forearm.

This article discusses ulnar, median, and radial nerve compression in the proximal forearm and elbow and some possible common misconceptions. In particular, the ligament of Struthers extremely rarely causes ulnar neuropathy. Lacertus syndrome and flexor superficialis-pronator syndrome can be diagnosed separately. Surgical release can be through a small incision. Acronyms for compression to radial nerve in proximal forearm can be simplified to radial tunnel syndrome, which includes a mild type (classical radial tunnel syndrome) and a severe type (posterior interosseous nerve (PIN) compression).

The Effects of Obesity and Bariatric Surgery on Rates of Upper Extremity Compression Neuropathies.

To estimate the effects of obesity on all types of upper extremity compression neuropathies (UECN) (carpal tunnel syndrome and other median nerve, radial nerve, and ulnar nerve compression neuropathies) and to assess whether bariatric surgery modifies these effects. UECN are increasingly prevalent and decrease the quality of life of affected individuals. Studies suggest obesity as a risk factor for carpal tunnel syndrome, the most common type of UECN. A retrospective cohort study was conducted using the PearlDiver Mariner Database, an all-payor claims database containing claims for over 53 million patients from 2010 to 2019 in all 50 US states. Rates and odds of all types of UECN were compared between 1:1:1 exact matched cohorts of obese patients who were medically managed, obese patients who underwent bariatric surgery, and nonobese patients (111,967 patients in each cohort). Compared with nonobese patients, patients with obesity were significantly more likely to develop any UECN (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.09-1.18), carpal tunnel syndrome (OR, 1.15; 95% CI, 1.10-1.30), and 2 or more UECN (OR, 1.34; 95% CI, 1.20-1.48). Compared with obese patients who were managed medically, obese patients who underwent bariatric surgery were significantly less likely to develop any UECN (OR, 0.87; 95% CI, 0.84-0.91) and carpal tunnel syndrome (OR, 0.85; 95% CI, 0.81-0.89). Obese patients have higher odds of both single and concomitant UECN, specifically carpal tunnel syndrome, compared with nonobese patients. Bariatric surgery decreases the odds of developing UECN compared with obese patients not undergoing surgical intervention.

Nerve compression due to benign tumors or ganglion cysts in the upper limb – case series

Tumor nerve compressions in the upper limb are relatively rare, usually involving ganglion cysts and benign tumors. We present a case series of five patients with peripheral nerve compression in the upper limb due to tumor or cystic masses- ulnar nerve compression in the Guyon’s tunnel due to a ganglion cyst, large median nerve schwannoma compressing anterior interosseous nerve and median nerve, voluminous lipoma compressing median nerve in the proximal forearm, superficial branch of radial nerve compression by a synovial cyst and elbow region lipoma compressing radial nerve. In the beginning, those benign lesions are asymptomatic but, as they continue to grow adjacent to a peripheral nerve clinical manifestations appear progressively as compressive neuropathies. After a preoperative imagistic analysis, tumor resection with careful dissection, in order to preserve the neurovascular structures, is the elective surgical procedure in order to obtain an optimal functional recovery.

Humeral shaft fracture associated with radial nerve palsy -a case report

Radial nerve palsy was induced by radial nerve compression, which was often caused by humerus bone fracture. This leads to pain, weakness, or loss of function mostly in the wrist, hand, and fingers. We reported a case of a 24-year-old male patient with complaints of swelling of the right-hand wrist joint and pain during extension and flexion while moving. He had a three-month history of mild displaced humeral shaft fracture from a traffic accident and an intramedullary Ender nailing was performed. He now has been admitted with swelling in his right wrist joint and pain while moving his hand. The case was diagnosed as Radial nerve palsy. Surgery was performed, the proximal and distal ends of the radial nerve were separated at the humeral bone's surface. The radial nerve stumps were enough long to be sutured. Our one-month follow-up shows no complications. The majority cases of radial nerve palsy will resolve within a few weeks after surgery, as our patient did, and the most prominent is patient education.

Nerve entrapment around elbow

Entrapment neuropathy around elbow is a common cause of disability across all age groups. The major nerves that traverse the elbow are ulnar, median and radial nerves and their branches. Cubital tunnel syndrome leading to ulnar nerve compression can often present with significant pain, paresthesia or weakness. Median and Radial nerve compression around the elbow, albeit less frequent, can also lead to significant morbidity and must be kept in the differential diagnosis when dealing with patients complaining of persistent pain around the elbow and weakness of forearm/hand muscles. Electrodiagnostic studies can be a useful adjunct to clinical examination, to help localize the site and quantify the grade of compression. Management should involve a trial of conservative treatment and failing that, surgical treatment should be considered. We hereby provide an overview of nerve entrapments around the elbow including their applied anatomy, etiology, clinical assessment and overview of the current concepts in surgical treatment.

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.

Radial nerve palsy following uncomplicated percutaneous nephrolithotomy

Injury to nerve is a well known complication of shoulder subluxation. Radial nerve injury is most commonly seen during percutaneous nephrolithotomy in lateral decubitus region. If the posterior aspect of the humerus is positioned incorrectly leads to radial nerve compression. Lateral decubitus position in percutaneous nephrolithotomy is the main position for posterior and lateral approaches. After percutaneous nephrolithotomy in lateral decubitus position reported the case of radial nerve palsy. A man of 26 year old from left (contralateral) percutaneous nephrolithotomy with signs of right radial nerve palsy on postoperative day number one. The body mass index is 28 &amp; underwent laterally attempted percutaneous nephrolithotomy on the left and he was located about 6 h and 30 min in the lateral decubitus position. Orthopedics, physiotherapy and electromyography were done to treat radial nerve palsy in the post-operative period. It demonstrates complication of the radial nerve palsy which may be related with percutaneous nephrolithotomy. Being aware of the complication can be used to stop pressure points at percutaneous nephrolithotomy in the lateral decubitus position.

The proximal humeral attachment of the lateral head of the triceps brachii: a cadaveric study and potential site for radial nerve compression.

Knowledge of potential compression sites of peripheral nerves is important to the clinician and surgeon alike. One anatomical location for potential compression of the radial nerve, which is rarely mentioned in the literature, is at the proximal humeral attachment of the lateral head of the triceps brachii at the level of the proximal spiral groove. As no anatomical studies have been devoted to this band, the present study was conducted. Ten adult fresh-frozen cadavers were dissected and the lateral head's attachment onto the posterior humerus evaluated for a band. This anatomy and its relation to the radial nerve during range of motion of the elbow and forearm were evaluated. A band was found on 15 of 20 arms. On five sides, the band was comprised of grossly muscle fibers of the lateral head of the triceps brachii and was not tendinous. The bands were crescent-shaped, straight, and duplicated on nine, five, and one arm, respectively. The length of the bands ranged from 1.1 to 2.2cm (mean 1.54cm). The width of the bands ranged from 0.5 to 1.1cm (mean 0.8cm). With elbow extension and the forearm in neutral, all bands were lax. With elbow extension and the forearm supinated, the bands became tauter less the muscular bands. In elbow extension and with the forearm in supination, the bands became most taut less the muscular bands. The presence of a fibrous band extending from the lateral head of the triceps brachii is common and should be among the differential diagnoses of anatomical sites for potential proximal radial nerve compression when other more common locations are ruled out.

Diabetes vignette. Weak left hand – query stroke in a diabetic double amputee

The patient was a 75-year-old bilateral amputee with insulin-treated type 2 diabetes, hypertension and dyslipidaemia controlled on treatment, and peripheral vascular disease treated with aspirin. He was admitted having fallen while transferring from wheelchair to bed; this was a simple fall and he had normal glucose and blood pressure levels. He was an ex-smoker, but his chest X-ray was normal. He was very rapidly back to his pre-admission state and abilities. On the ward he was mobile unaided in his wheelchair, administering his own insulin; he enjoyed zipping along the smooth hospital corridors and going to the local pub either with permission and a member of staff, or with neither, but only ever drank 1 or 2 pints. A seminal paper on outcomes post amputation stated that only 5% of amputees rehabilitated well, to become independent of their wheelchair, and that more consideration should be given to surgery that optimised wheelchair rehabilitation;1 our patient was an excellent example of someone who was very able in a wheelchair. He was a bit of a rascal who spoke his mind; thus, he remained in hospital for four weeks with ongoing negotiations about returning home to his very sheltered residence who had a ‘can't do’ mentality. During his hospital stay, he developed a weak left hand (see Figure 1); stroke was diagnosed and CT scan brain showed an old small infarct in the cerebellum, but was otherwise normal. On careful examination he had a wrist drop with weak wrist and finger extension (0/5 MRC power scale) but wrist and finger flexion, and finger abduction and adduction were normal; there was numbness on the dorso-radial aspect of the hand. When examining a hand with wrist drop, it is important to support the hand in its neutral position to allow the intrinsic hand muscles (innervated by ulnar and median nerves) to not work at a disadvantage, otherwise these muscles may appear weak. It is well recognised that several entrapment neuropathies are associated with diabetes such as median, ulnar, and lateral popliteal nerves, and lateral cutaneous nerve of thigh;2 however, data on an association between radial nerve palsy and diabetes are scarce, despite the evidence that the nerves of people with diabetes are more prone to compression neuropathies.3 A leading textbook states that radial nerve palsy is not related to diabetes, but a pressure palsy had been seen following hypoglycaemic unconsciousness.4 However, Stamboulis and colleagues reviewed patients with focal neuropathies referred for nerve conduction studies; the prevalence of known diabetes in people with radial nerve palsies was 28% versus a local population prevalence of known diabetes of 7%.5 Causes of radial nerve palsy include fractured neck of humerus, gunshot wounds, and lying on the nerve due to decreased consciousness;6 none of these applied to our patient who never returned from the pub drunk, and whose blood glucose monitoring was consistently in the 5–10mmol/L range. In most wheelchair users, the weight of their two legs prevents the wheelchair from tipping over backwards. But this is a problem for double amputees; hence for double amputees, including our patient, the wheelchair rear wheels are moved further back7 to regain balance. It was noticed that as the patient was zooming around the hospital, he would move his arms far back for rapid self-propulsion and catch the inner upper arm on the wheelchair handles; this seemed the likely cause of his neuropraxia. Standard treatment of compression radial nerve palsy is to splint the wrist to allow the hand muscles to function with a good grip,6 and wait and see; this was done as well as advice to slow down. After one week, the wrist drop was markedly improved; radial nerve compression palsies are generally neuropraxic and resolve within one week. Unfortunately, one month after discharge the patient died suddenly, presumably from cardiovascular causes, exemplifying the high mortality rate of amputees.1 Accurate clinical skills and knowledge are important to avoid unnecessary consultations and investigations, particularly in these times of coronavirus pandemic. Alternatively, if one practises using pattern recognition, this just looks like a radial wrist drop.

Intermuscular Connections in Anterior Brachium: its Implications in Radial Nerve Entrapment Neuropathy

SUMMARY Background. Radial nerve (RN) is the largest branch arising from the brachial plexus, which supplies the extensor muscles and skin. This nerve may go for entrapment anywhere in its course. Muscular and tendinous variations have been implicated in various nerve entrapment syndromes along with other causes. The goal of this investigation was to observe for any connections between brachialis (BL) and brachioradialis (BR) muscles that may compress the radial nerve or its terminal branches. Methods. The study was performed on 84 formalin fixed human cadaveric upper limbs. Meticulous dissection in and around the cubital region was carried out to expose the BL, BR and the RN. The connections between the two muscles were noted and classified as muscular split type, muscular slip type and tendinous type. Results. Exploration of the cubital region revealed connecting bridges in 24 of the specimens (28.5% cases). 17 (20.2%) specimens exhibited split type, 6 (7.1%) specimens muscular slip type and 1 (1.2%) upper limb presented tendinous connection. In all these cases, the connecting bridge between the two muscles was oblique and crossed the RN. Conclusions. The results of our study reveal that various types of connections exist between the two muscles, contributing to the factors leading to radial nerve compression. Knowledge about this anatomical entity will be helpful in further understanding the aetiology of radial nerve compression and in devising effective treatment

Intermuscular Connections in Anterior Brachium: its Implications in Radial Nerve Entrapment Neuropathy

SUMMARY Background. Radial nerve (RN) is the largest branch arising from the brachial plexus, which supplies the extensor muscles and skin. This nerve may go for entrapment anywhere in its course. Muscular and tendinous variations have been implicated in various nerve entrapment syndromes along with other causes. The goal of this investigation was to observe for any connections between brachialis (BL) and brachioradialis (BR) muscles that may compress the radial nerve or its terminal branches. Methods. The study was performed on 84 formalin fixed human cadaveric upper limbs. Meticulous dissection in and around the cubital region was carried out to expose the BL, BR and the RN. The connections between the two muscles were noted and classified as muscular split type, muscular slip type and tendinous type. Results. Exploration of the cubital region revealed connecting bridges in 24 of the specimens (28.5% cases). 17 (20.2%) specimens exhibited split type, 6 (7.1%) specimens muscular slip type and 1 (1.2%) upper limb presented tendinous connection. In all these cases, the connecting bridge between the two muscles was oblique and crossed the RN. Conclusions. The results of our study reveal that various types of connections exist between the two muscles, contributing to the factors leading to radial nerve compression. Knowledge about this anatomical entity will be helpful in further understanding the aetiology of radial nerve compression and in devising effective treatment