A 53-year-old man with weakness in the right arm since waking up; On exam, he cannot straighten the fingers or extend the wrist, with decreased sensation over the back of the right hand. What is the most appropriate next step?

• A. Obtain wrist X-ray and immobilize
• B. Start anticoagulation
• C. Apply a wrist splint
• D. Order an MRI of the brain

Answer: (C)

The situation shows a focal peripheral nerve problem: loss of wrist and finger extension with sensory loss on the dorsum of the hand localizes to radial nerve palsy. The best next step is to immobilize the wrist with a splint that keeps the wrist in extension. This positioning protects the joint from flexion contractures, preserves hand function, and allows the nerve time to recover, which is the typical approach when a radial nerve palsy is suspected and there is no signs of an acute central process or trauma needing imaging.

Ordering an MRI of the brain isn’t indicated here because the pattern fits a peripheral nerve injury, not a central (brain) lesion. Starting anticoagulation isn’t appropriate for a peripheral nerve palsy. Obtaining a wrist X-ray isn’t necessary unless there’s trauma or fracture suspected.