Case Challenge

Stephen J Pomeranz

Gain confidence interpreting Forearm MRI Cases with MRI Online. Quiz yourself using real-world, interactive scrollable cases & earn CME. Try it free!

Case Review

Musculoskeletal (MSK)

Post-Course Activities

This Power Pack is comprised of 25 unique Forearm MRI cases that you can scroll through in our diagnostic web viewer to determine your findings. Quiz yourself and earn CME.

Forearm MRI Cases

Case 23 - 41-year-old female presents with clinical radial neuropathy

<div>HISTORY:&#160;This 41-year-old female presents with clinical radial neuropathy and right wrist drop. History of several falls while not using her cane at home.(QUIZ ANSWER) THE DENERVATION MUSCLE SIGNAL INVOLVES:&#160;All of the above.Using the&#160;diagnostic web viewer, we have provided images that assist in telling our clinical story. Areas of significance are indicated below.FINDINGS: Radius intact. Ulna intact. No suspicious osseous lesion or macrofracture about either bone. No elbow dislocation. No wrist dislocation.&#160;Denervation muscle signal involves supinator, extensor carpi ulnaris, extensor digitorum communis, extensor carpi radialis brevis, extensor carpi radialis longus, brachioradialis and pronator quadratus. Flexor group is without muscular strain or denervation muscle signal. No compartment syndrome. No extraskeletal suspicious osseous lesion. No entrapment neuropathy involves the ulnar nerve as it exits the cubital tunnel and enters the soft tunnel. No entrapment neuropathy involving the median nerve at the level of the antecubital fossa. No entrapment neuropathy involves the radial nerve or the posterior interosseous nerve branch.&#160;Mild distention of the palmar distal radial recess. Increased cross-sectional volume measuring 0.15 square centimeter involves the median nerve at the level of the carpal tunnel outlet along with more than 2mm of bowstringing of the flexor retinaculum. Paucity of fat also seen within the carpal tunnel. Flexor and extensor tendons of the wrist intact.&#160;CONCLUSION:&#160;Indirect signs of posterior interosseous nerve syndrome of Frohse's arcade:1. Denervation muscle signal isolated to the extensor muscle group compatible with a radial nerve palsy. A definitive site of entrapment or cystic denervation involving radial nerve from the level of the elbow through to the level of the wrist is not observed. Common sites for such neuropathy include fractures of the mid humerus, fibrous bands of lateral head triceps and accessory subscapularis-teres-latissimus muscle variant. The need for more proximal neurographic evaluation should be determined clinically.&#160;2. Increased volume of median nerve as it exits the cubital tunnel, paucity of fat within the cubital tunnel and bowstringing of the flexor retinaculum. Findings favor entrapment neuropathy of the distal median nerve (carpal tunnel syndrome).</div>

Case

In this case, there is denervation muscle signal involving which of the following?