Investigations take the form of:
Radiographs
In suspected entrapment of the radial nerve in the arm, radiographs are required to detect, or rule out, a fracture, healing callus or tumours as the cause of entrapment.
MRI
MRI is useful in detecting tumours such as lipomas and ganglions, as well as aneurysms and rheumatoid synovitis.
Diagnostic procedures
EMGs help to locate the site of injury and help the clinician monitor the nerve recovery over time.
EMGs may not be positive for 3-6 weeks following injury.