A 51-year-old woman comes to the physician complaining that the right side of her face has felt "funny" for the past 12 hours. Her past medical history is significant for type 2 diabetes mellitus. Physical examination reveals asymmetry of her face when she smiles, puffs out her cheeks, and closes her eyes tightly. There is also effacement of the right nasolabial fold, and her mouth is drawn toward the left side.