Solving the Case and Why Neural Presentations Get Blurred

Thumb extension is supplied by C8, yet the pain fit C6. Andy tested the LOAF muscles for C8, extensor indicis, extensor digiti minimi and extensor digitorum for the posterior interosseous nerve, and extensor pollicis longus locally. All were 5 out of 5, and radial nerve interface tests were negative. His hypothesis was radicular pain with a local tendon injury. MRI showed C6 and C8 root impingement, nerve conduction was normal, and ultrasound found an abductor pollicis longus tendon rupture. Without the cross-check she could have been referred for C8 radiculopathy surgery instead of to upper limb orthopedics. A 2022 study by Hong and colleagues found that only about 50 to 60% of confirmed single-level radiculopathies matched textbook sensory maps, and C6 motor loss was often atypical. Causes include muscles with more than one root, Martin-Gruber anastomoses and pre-fixed or post-fixed plexuses, neuroinflammation, and coexisting entrapments: about 10% of people with cervical radiculopathy also have carpal tunnel syndrome. The key takeaways are to use the LOAF muscles, check wrist flexors and pronators, and reassess when findings do not fit.