• Journal of Electrodiagnosis and Neuromuscular Diseases
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• v.20 no.2
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• pp.153-158
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• 2018

Posterior interosseus (PI) nerve compression is a rare form of compressive neuropathy. It can cause pain along the radial nerve course and weakness of radial nerve innervating muscles without sensory symptoms. A 65-year-old man visited our institution complaining weakness of finger extension and thumb abduction after 2 times of injections at the right elbow in local clinic. The patient's clinical history and physical examination implied an iatrogenic radial nerve injury caused by the injection. The electrophysiologic study revealed of posterior interosseus neuropathy (PIN) with incomplete conduction block. However, the ultrasound study showed that the PI nerve was compressed by an anechoic cyst. The magnetic resonance imaging also confirmed of a ganglion cyst, not a hematoma. After repeated aspirations and a steroid injection, the electrophysiologic study showed recovery of motor weakness. Despite of the clue which implying an iatrogenic injury, clinician should consider other possibilities such as ganglion cysts and ultrasound guided aspiration and steroid injection could be an effective option for conservative management.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.2
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• pp.165-170
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• 2009

Lipoma is the most common benign soft tissue tumor. But the parosteal lipoma which occurs in deep tissue is very rare. The authors experienced a case of parosteal lipoma causing posterior interosseous nerve palsy around the proximal radius. A 53-year old male patient, who has motor weakness on right wrist and finger extension for 3 weeks visited. He was diagnosed as a parosteal lipoma causing postrior interosseous nerve palsy of the proximal radius. 6 months after the marginal excision, he was recovered from motor weakness.