Age / Sex : 47 / M

Chief complaint :

Left wrist drop and tingling sensation on left hand 1st web for 1 month


What is your diagnosis?

Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer).


Courtesy : 이호석, Hoseok Lee, 경북대학교병원, Kyungpook national university hospital

Radial nerve torsion

Discussion

Findings:

Hour-glass appearance with swelling of radial nerve

Hyperintense of radial nerve on PDWI and fat-suppressed T2WI

Hypoechogenecity with loss of fascicular pattern of radial nerve on US

Differential Diagnosis:

Compressive neuropathy

Idiopathic neuritis

Discussion:

Twisting of nerve fascicles, also known as nerve torsion, is a rare cause of peripheral nerve palsy in the upper extremity. Its pathogenesis is unclear, but most believe that intrafascicular adhesions due to either inflammation or microvascular injury make the nerve susceptible to twisting, and repetitive motion of the extremity may lead to actual torsion. Intraoperatively, frank torsions of nerve fascicles have been found at areas of hourglass-like constrictions

References:

Skeletal Radiol. 2015; 44(3):457-61