Certified Neuroscience Registered Nurse (CNRN) Practice Exam

What are the most common signs of Erb's palsy?

1. Swollen joints and fever

2. Loss of sensation and paralysis of arm muscles

3. Persistent pain in the shoulder

4. Increased motion range in the arm

The correct answer is: Loss of sensation and paralysis of arm muscles

The signs of Erb's palsy are primarily associated with damage to the upper trunk of the brachial plexus, often occurring during birth when excessive lateral traction on the baby's head delivers a significant force on the nerves that control the arm. Loss of sensation and paralysis of arm muscles are hallmark symptoms in affected individuals. The injury typically results in weakness, which can lead to limited mobility in the arm on the affected side, commonly featuring a characteristic “waiter's tip” posture where the affected arm hangs by the side and is rotated internally. In contrast, the other options do not accurately reflect the clinical presentation of Erb's palsy. Swollen joints and fever are more indicative of infections or inflammatory joint conditions rather than a neurological disorder caused by nerve damage. Persistent pain in the shoulder may occur in some cases, but it is not a defining sign of Erb's palsy and is more often related to other musculoskeletal injuries. Increased motion range in the arm contradicts the typical weak and limited functional range seen in affected individuals, as Erb's palsy leads to decreased muscle control and strength in the arm. Therefore, recognizing loss of sensation and paralysis as the primary signs is essential for understanding and identifying this condition accurately.