Is Bell's palsy considered a LMN or UMN CN VII palsy?

• A. Upper motor neuron
• B. Lower motor neuron
• C. Mixed
• D. No involvement

Answer: (B)

Bell's palsy is a peripheral, lower motor neuron lesion of the facial nerve (CN VII). Because the pathology lies after CN VII exits the brainstem, it knocks out all the muscles of facial expression on the same side. That means weakness of the entire half of the face, including the forehead, eye closure, and mouth. In contrast, an upper motor neuron lesion affecting the corticobulbar pathways to CN VII typically causes weakness only of the lower face on the opposite side, with the forehead muscles spared due to bilateral innervation. The full ipsilateral involvement of the forehead in Bell's palsy is the hallmark of a lower motor neuron CN VII palsy, making the lower motor neuron option the correct description.