35-year-old man presents with a 2-day history of right-sided facial weakness. He is otherwise fit and well.There is no past history of neurological symptoms. There is no history of preceding infection. On examination, the middle ear is normal, the salivary glands are not enlarged, and there are no other cranial nerves affected. The forehead is not spared. Neurological examination of the limbs is unremarkable. Routine investigations are all normal. Which of the following represents the most reasonable management plan?