What type of neural impairment causes Bell's Palsy?

Bell's Palsy is primarily caused by an infection and inflammation of cranial nerve 7, which is also known as the facial nerve. This nerve is responsible for controlling the muscles of facial expression, and when it becomes inflamed, it leads to the characteristic weakness or paralysis on one side of the face. Such inflammation can be triggered by viral infections, such as the herpes simplex virus.

This condition affects the lower motor neurons associated with the facial nerve, which differentiates it from issues related to the upper motor neuron. Upper motor neuron damage typically results in a different pattern of weakness that is not consistent with Bell's Palsy. Thus, understanding that the issue arises specifically with cranial nerve 7 solidifies why the correct answer focuses on infection and inflammation involving this nerve rather than any other neural impairment.