Radial neuropathy

Right radial nerve decompression for refractory radial tunnel syndrome

Background:

Radial tunnel syndrome arises due to compression of the radial nerve through the radial tunnel.[1,5] The radial nerve divides into superficial and deep branches in the forearm. The deep branch travels posteriorly through the heads of the supinator where compression commonly occurs.[3,9,7] This syndrome results in pain in the hand and forearm with no motor weakness.[8] This condition can be treated conservatively with splinting and anti-inflammatory medication.[2,4,6] For cases of refractory radial tunnel syndrome, surgical management can be considered. Herein, we have presented a step-by-step video guide on how to perform a radial nerve decompression with a review of the relevant anatomy and surgical considerations.

Case Description:

A 68-year-old right-handed woman presented to the Mayo Clinic (Scottsdale, AZ) with the right elbow pain which radiated to the forearm causing significant difficulties with daily tasks. She had been dealing with worsening symptoms for 4 months. The patient’s history of gardening and clinical presentation allowed for diagnosis of radial tunnel syndrome. After conservative measures failed and other differential diagnoses were excluded, surgical decompression was recommended to treat her symptoms. The patient’s right arm was marked preoperatively between the brachioradialis and extensor carpi radialis longus (ECRL) muscles. The posterior cutaneous nerve of the forearm was identified which allowed for the determination of the interval between the brachioradialis and ECRL. Separation of the two muscles allowed for the identification of the radial sensory nerve. A nerve stimulator was used to confirm the sensory nature of this nerve. The nerve to the extensor carpi radialis brevis (ECRB) was identified and retracted with a vessel loop. Dorsal to the nerve to the ECRB is the posterior interosseous nerve (PIN), which was identified and retracted with a vessel loop. The fascia of the ECRB was divided both longitudinally and transversely and the supinator below was identified. The supinator muscle was carefully divided to further decompress the PIN. Informed consent for publication of this material was obtained from the patient.

Conclusion:

The patient tolerated the procedure well and reported significantly reduced pain at 7-month follow-up. To the best of our knowledge, video tutorials on this procedure have not been published. This video can serve as an educational guide for peripheral nerve specialists dealing with similar lesions.

Electrodiagnostic Testing of Entrapment Neuropathies: A Review of Existing Guidelines

Entrapment neuropathies cover a wide range of isolated nerve injuries along the course of the upper and lower extremity nerves. Electrodiagnostic (EDX) testing is usually an essential part of the evaluation of entrapment neuropathies, and examinations for the most common entrapment neuropathies, carpal tunnel syndrome and ulnar neuropathy at the elbow, constitute a significant part of the daily work in EDX laboratories. Despite this, guidelines for EDX testing are generally sparse or do not exist for entrapment neuropathies, whereas a wide variety of different techniques are available to the clinical neurophysiologist. This study reviews the existing, more or less, detailed EDX criteria or practice parameters that are suggested by consensus groups in peer-reviewed journals for the most common entrapment neuropathies: carpal tunnel syndrome, ulnar neuropathy at the elbow, common peroneal (fibular) neuropathy at the fibular head, and tibial neuropathy at the tarsal tunnel. It is concluded that future research is needed to develop and refine EDX guidelines in entrapment neuropathies.

Electrophysiologic Features of Radial Neuropathy in Childhood and Adolescence

BACKGROUND

We analyzed the clinical and electrophysiologic patterns of nerve injury in pediatric patients with radial neuropathy.

METHODS

This is a retrospective analysis of 19 children and adolescents with radial neuropathy.

RESULTS

The mean subject age was 12 years (range one month to 19 years), 56% were female, and 53% had traumatic etiologies. Weakness in the finger and wrist extensors was the prevailing complaint (82%). Predominant localization was at the posterior interosseous nerve (37%), followed by the radial nerve below the spiral groove (32%), the radial nerve at the spiral groove (26%), and the radial nerve above the spiral groove (5%). Extensor indicis proprius compound muscle action potential amplitude was reduced in 86% of cases when tested, with a median axon loss estimate of 78%. The radial sensory nerve action potential amplitude was reduced in 53% of all cases, and in 83% of cases affecting the main radial trunk with a median axon loss estimate of 100%. For neuropathy affecting the main radial trunk, there was a high correlation of extensor indicis proprius median axon loss estimate and radial sensory nerve action potential median axon loss estimate (r = 0.72, P = 0.02). Neurogenic changes were seen in the extensor indicis proprius, extensor digitorum communis, extensor carpi radialis, and brachioradialis in 88%, 94%, 60%, and 44% of cases, respectively. Pathophysiology was demyelinating in 10%, axonal in 58%, and mixed in 32%.

CONCLUSIONS

In contrast to adults, where localization at the spiral groove predominates, radial neuropathy in children and adolescents is commonly localized at the posterior interosseous nerve or at the distal main radial trunk. Pediatric radial neuropathy is frequently of traumatic etiology and axonal pathophysiology.

Posterior interosseous nerve syndrome due to intramuscular lipoma

Lipomas are extremely common benign soft tissue tumors that are usually subcutaneous and asymptomatic. However, an intramuscular lipoma, occurring adjacent to the proximal radius, may easily cause paralysis of the posterior interosseous nerve because of a specific anatomical relationship of these structures in that area. In this report, we describe an unusual case of a 48-year-old-woman with a posterior interosseous nerve syndrome due to an intramuscular lipoma. The patient had good recovery after surgery and rehabilitation physiotherapy.

Electrodiagnostic evaluation of ulnar neuropathy and other upper extremity mononeuropathies

Upper extremity mononeuropathies are some of the common disorders seen in neurophysiology laboratories. Electrophysiologic studies rely on accurate localization based on knowledge of applicable anatomy and features of history and physical examination. Careful electrodiagnostic studies provide an accurate diagnosis, help localize the lesion site, exclude alternate diagnoses, reveal unsuspected diagnoses, determine pathophysiology of lesions, and assess severity, timeframe, and prognosis of lesions. This article discusses the electrodiagnostic approach to ulnar neuropathy, proximal median neuropathy, radial neuropathy, musculocutaneous neuropathy, axillary neuropathy, suprascapular neuropathy, and long thoracic neuropathy. Pertinent aspects of the history and physical examination, nerve conduction studies, and electromyography are presented.

Forearm pain, diagnosed as intersection syndrome, managed by taping: a case series

STUDY DESIGN

Case series.

BACKGROUND

Intersection syndrome is an overuse injury of the forearm. Taping has been described for the management of soft tissue injuries, yet there has been no report for the management of intersection syndrome using this method. The purpose of this case series was, therefore, to describe the efficacy of taping for the management of intersection syndrome.

CASE DESCRIPTION

Five patients with intersection syndrome were managed by taping, in an effort to reduce crepitus induced by thumb movements. Nonstretch sports tape was applied, with an ulnarly directed tension force across the dorsal aspect of the forearm. Taping was performed daily for 3 weeks. Follow-up took place at 1, 2, 3, and 4 weeks, and at 1 year from the initial consultation.

OUTCOMES

All patients demonstrated complete elimination of crepitus with the application of tape. Crepitus induced by wrist movements, tenderness over the dorsal forearm, and swelling were no longer present at 3-week follow-up. Disability identified by the disability/symptom subscale of the Disabilities of the Arm, Shoulder and Hand questionnaire decreased at 3-week follow-up, and this reduction was maintained at 4-week and 1-year follow-ups.

DISCUSSION

Taping improved symptoms and function in this small case series. One possible explanation for this improvement may be the alteration of soft tissue alignment.

LEVEL OF EVIDENCE

Therapy, level 4.

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.

Mononeuropathies of the radial nerve: clinical and neurographic findings in 91 consecutive cases

Retrospective features of 91 consecutive cases (68 men, 23 women; mean age 44.4 years) of radial mononeuropathy diagnosed over the last 8 years in two electromyography (EMG) services are reported to define the clinical and electrophysiological findings of radial neuropathies in relation to traumatic and non-traumatic causes and site of injury. The occurrence of radial neuropathy was 0.65 x 100 first electromyographic examinations. The most frequent site of damage was the main trunk at the spiral groove of the humerus (36%); the most frequent cause was nerve trauma (70%) due to fracture (36%). In neuropathies of the main trunk and posterior interosseous (PI) nerve, "complete nerve injury" was observed in 36% of cases, conduction motor block in 33% and motor conduction velocity slowing in 46%. At least one of these findings was present in 51%, whereas motor neurography was normal in 13% of cases. Sensory action potential (SAP) anomalies were observed in 51% of cases. In neuropathy of the superficial radial nerve, no SAP was detected in 30% of cases; in all others except one, SAP was reduced in amplitude. Non-traumatic neuropathies showed severer conduction block and less severe anomalies of SAP than traumatic neuropathies. No differences were found between men and women. EMG is essential for confirming the site of injury and neurographic study may be helpful for diagnosis, providing information about lesion type and severity.

MRI diagnosis of occult ganglion compression of the posterior interosseous nerve and associated supinator muscle pathology

Occult interosseous ganglions in the proximal forearm can result in pain and decreased supination. We will describe the magnetic resonance imaging (MRI) diagnosis of an interesting case of supinator atrophy secondary to compression of the posterior interosseous branch of the radial nerve. A brief review of this entity follows.

Posterior antebrachial cutaneous nerve conduction study in radial neuropathy

Radial neuropathy most commonly occurs as a result of external compression at the spiral groove region. The posterior antebrachial cutaneous nerve (PACN) conduction study was performed in 15 consecutive patients with radial palsy. Unilateral PACN abnormalities were present in 11 patients. A normal PACN study was correlated with clinical improvement at 3 months. Conversely, PACN abnormality was correlated with radial motor axon loss and a poorer prognosis. The PACN study is a simple adjunct which provides additional information relating to the diagnosis and prognosis of radial lesions.

Electrodiagnostic approach to the patient with suspected mononeuropathy of the upper extremity

Upper extremity mononeuropathies are common. Most are due to compression, whereas others occur in the setting of systemic disorders (e.g., diabetes) or with coexistent polyneuropathies. Electrophysiologic studies are essential in most cases, and provide critical information regarding localization, severity, activity, chronicity, and underlying pathophysiological mechanisms. Insights gleaned from the electrodiagnostic report guide clinicians in the optimal management of mononeuropathies of the upper extremity.

Bilateral transient radial nerve palsies in an infant after cardiac surgery

PURPOSE

To describe the case of an infant who suffered bilateral transient radial nerve palsies after cardiac surgery.

CLINICAL FEATURES

A one-month-old baby was found to have bilateral wrist and finger drop after the removal of splints that has been applied to the right hand for 14 days and to the right hand for six days during perioperative management of Blalock-Taussig shunt surgery. The hand splints had been applied to the forearms with adhesive silky tape to keep peripheral vascular lines in place. The patient also suffered from several episodes of cardiogenic shock, hypoxemia and generalized edema relating to cardiac dysfunction during this fine period. Given the findings of no impairment of median or ulnar nerves and brachioradial muscle, it was suspected that bandaging with adhesive tapes caused peripheral radial nerve damage at the level of posterior interosseus nerve on forearm. Diminished oxygen delivery and edema may additionally have contributed to peripheral nerve ischemia. The aforementioned neurologic symptoms resolved spontaneously after several days.

CONCLUSION

Prolonged compression by bandaging of splints on forearm may have resulted in ischemic damage to the posterior interosseus nerve branch combined with extensor carpi radialis longus nerve branch of the radial nerve. We should attempt to reduce the frequency and duration of splinting of the extremities, especially in sedated, paralyzed babies, given the potential risk of compression neuropathy.