Phrenic nerve palsy may persist for up to which time frame before resolution is expected?

• A. Up to 12 Months
• B. 24 Hours
• C. 2 Weeks
• D. 5 Years

Answer: (A)

Recovery after phrenic nerve injury happens gradually as the nerve fibers regrow and reinnervate the diaphragm. Nerve regeneration proceeds at a slow pace (roughly 1–3 mm per day), so meaningful improvement typically appears over months, with many cases resolving within about a year. That’s why the best answer is up to 12 months. Times like 24 hours or two weeks are too soon for actual nerve healing to manifest, and while rare cases can persist longer, five years is not the typical expectation. If no improvement is seen after about a year, further evaluation for persistent diaphragmatic paralysis or alternative causes is usually considered.