Bell's palsy is characterized by which of the following?

• A. Ipsilateral facial paralysis with inability to close the affected eye
• B. Bilateral facial paralysis
• C. Loss of auditory function
• D. Limb weakness

Answer: (A)

Bell's palsy is a peripheral, unilateral palsy of the facial nerve (cranial nerve VII), which leads to weakness of all the muscles on the affected side of the face, including the muscle that closes the eye. The eye cannot be closed because the orbicularis oculi is paralyzed, a hallmark of this condition. This reflects a lower motor neuron lesion of the facial nerve, so the weakness is on one side and involves the entire half of the face rather than just part of it. The other options point to involvement of different nerves or systems (bilateral facial weakness, hearing loss from the auditory nerve, or limb weakness), which are not characteristic features of Bell's palsy.