Which is a classic clinical feature of Bell's palsy?

• A. Sudden unilateral facial weakness with poor eye closure; usually improves spontaneously.
• B. Bilateral facial weakness with persistent eye closing difficulty.
• C. Loss of pain sensation in the face.
• D. Weakness of the limbs without facial involvement.

Answer: (A)

Bell's palsy is an acute, lower motor neuron palsy of the facial nerve on one side. The key feature is sudden weakness of all facial muscles on the affected side, including an inability to close the eye tightly. This eye-closure deficit is a telltale sign of a facial nerve (peripheral) problem. Most people recover spontaneously over weeks to months, which is why this presentation—sudden unilateral facial weakness with poor eye closure that improves on its own—is classic.

This helps distinguish it from other causes of facial weakness: bilateral facial weakness suggests a different process (like a systemic or bilateral neuropathy), loss of facial sensation points to trigeminal nerve involvement, and weakness of the limbs without facial involvement indicates a non-facial motor disorder or central process. In practice, recognizing the unilateral, LMN pattern with eye-closure difficulty and the tendency toward spontaneous recovery points to Bell's palsy.