Posterior Interosseous Nerve Palsy Caused by a Ganglion of the Arcade of Frohse

A 51-year-old male who is right-handed visited the outpatient for right fingers-drop. The patient's fingers, including thumb, were not extended on metacarpophalangeal joint. The active motion of the right wrist was available. The electromyography and nerve conduction velocity study were consistent with the posterior interosseous neuropathy. Further evaluation was done with the magnetic resonance imaging for finding the space-occupying lesion or any possible soft tissue lesion around the radial nerve pathway. On magnetic resonance imaging, the ganglion cyst, which was about 1.8 cm in diameter, was observed on the proximal part of the superficial layer of the supinator muscle (Arcade of Frohse). The surgical excision was done on the base of ganglion cyst at the base of stalk of cyst which looked to be connected with proximal radioulnar joint capsule. The palsy had completely resolved when the patient was observed on the outpatient department a month after the operation.

Clinical Features of Wrist Drop Caused by Compressive Radial Neuropathy and Its Anatomical Considerations

OBJECTIVE: Posture-induced radial neuropathy, known as Saturday night palsy, occurs because of compression of the radial nerve. The clinical symptoms of radial neuropathy are similar to stroke or a herniated cervical disk, which makes it difficult to diagnose and sometimes leads to inappropriate evaluations. The purpose of our study was to establish the clinical characteristics and diagnostic assessment of compressive radial neuropathy. METHODS: Retrospectively, we reviewed neurophysiologic studies on 25 patients diagnosed with radial nerve palsy, who experienced wrist drop after maintaining a certain posture for an extended period. The neurologic presentations, clinical prognosis, and electrophysiology of the patients were obtained from medical records. RESULTS: Subjects were 19 males and 6 females. The median age at diagnosis was 46 years. The right arm was affected in 13 patients and the left arm in 12 patients. The condition was induced by sleeping with the arms hanging over the armrest of a chair because of drunkenness, sleeping while bending the arm under the pillow, during drinking, and unknown. The most common clinical presentation was a wrist drop and paresthesia on the dorsum of the 1st to 3rd fingers. Improvement began after a mean of 2.4 weeks. Electrophysiologic evaluation was performed after 2 weeks that revealed delayed nerve conduction velocity in all patients. CONCLUSION: Wrist drop is an entrapment syndrome that has a good prognosis within several weeks. Awareness of its clinical characteristics and diagnostic assessment methods may help clinicians make diagnosis of radial neuropathy and exclude irrelevant evaluations.

Topographic Anatomy on the Supinator Muscle and the Deep Radial Nerve in Relation with its Entrapment Syndrome / 대한해부학회지

The deep radial nerve could be compressed by the medial border of the extensor carpi radialis brevis muscle, superior or inferior border of the superficial layer of the supinator muscle and pathologic structures between two layers of the supinator muscle. The aim of this study was to clarify the topographic relationships between the deep radial nerve and the supinator muscle in the place where the entrapment syndrome of the nerve could be occurred. Sixty-six Korean adult cadavers (124 arms) were used. The angles of the deep radial nerve with the radius were measured on the anteroposterior and lateral radiographs. The average distance between a line through the tips of both epicondyles of the humerus, and the division sites of the radial nerve into superficial and deep branches, was 16.8+/-12.8 mm in the cases where the division sites were proximal to the line, and 7.8+/-5.0 mm in the cases where the division sites were distal to the line. The arcade of Frohse was 32.2+/-6.6 mm apart from the line connecting both tips of humeral epicondyles. The average length of the deep radial nerve covered by the superficial layer of the supinator muscle was 35.1+/-8.0 mm. The arcade of Frohse was classified into two types; semi-circular type in 68.6% and dull curved line type in 31.4%. The lateral border of the arcade of Frohse was composed of muscle, tendon, and both muscle and tendon in 12.1%, 26.6%, and 61.3%, respectively. The muscle fibers of two layers of the supinator muscle were fused with each other, at the area where the deep radial nerve came out between two layers of the muscle. The average angles of the deep radial nerve with the radius, were 23.4+/-4.6 degrees and 13.7+/-5.3 degrees, on the anteroposterior and lateral radiographs, respectively. The inferior border of the superficial layer of the supinator muscle was composed of tendon, muscle, and both muscle and tendon in 61.5%, 12.5%, and 17.3%, respectively. We discussed about the morphologic variations which could cause the entrapment syndrome of the deep radial nerve in the proximal and distal portions of the supinator muscle, and between the superficial and deep layers of the muscle.

Posterior Interosseous Nerve(PIN) Syndrome Caused by Anomalous Vascular Leash

Posterior interosseous nerve(PIN) syndrome is an entrapment of the deep branch of the radial nerve just distal to the elbow joint. It is caused by acute trauma or masses compressing the nerve. We report an unusual case of PIN syndrome with wrist drop caused by compression of the nerve by anomalous vascular leash. The patient has recovered with the surgical decompression of the offending vessels and arcade of Frohse.

Posterior Interosseous Nerve Syndrome: Case of Report

The authors reported the one case of posterior interosseous nerve syndrome, which had been operated and shown the good result. The posterior interosseous nerve syndrome is a neuropathy of deep musclar branch of the radial nerve. This nerve can be compressed by tumors, ganglia, elbow synovitis, or by a spontaneous compression that may occur at the point of passage through the 'arcade of Frohse'. This case had shown the vascular leash constricting the posterior interosseous nerve justproximal to the arcadet of Frohse, and the nerve below the constriction was atrophied. We reviewed other cases from the iterature in view of clinical features and management.