Phrenic nerve palsy is defined as

• A. Not resolved after discharge, but resolves by 12 months
• B. Fully resolves within 24 hours
• C. Permanent diaphragmatic paralysis
• D. No diaphragmatic dysfunction

Answer: (A)

Phrenic nerve palsy describes diaphragmatic dysfunction caused by injury to the phrenic nerve, which is usually temporary rather than permanent. The key idea is the typical recovery timeline: the deficit may persist after the initial care period, but most cases regain function within about a year. If diaphragmatic function has not recovered by 12 months, it is considered permanently affected. So the statement that fits describes a scenario where it isn’t resolved by discharge but tends to resolve within 12 months.

The other ideas don’t match this pattern: recovery within 24 hours is unrealistically rapid for nerve injury, suggesting full restoration almost immediately; permanent diaphragmatic paralysis would imply no recovery by 12 months; and having no diaphragmatic dysfunction contradicts the existence of phrenic nerve palsy.