Stroke of (Bad) Luck

 Question: A 58 year old female undergoes resection of a right sided 2.9 cm vestibular schwannoma via retrosigmoid craniotomy. On postoperative day 1, she has mild first-degree nystagmus and House-Brackmann grade 2 facial function. On postoperative day 3, she experiences acute headache, dizziness, nausea, vomiting, and her facial function declines to House-Brackmann grade 6. A stroke in the lateral pons is identified on CT. What artery supplies this area of the brainstem?

[Answer will be posted with next week's new question]

Answer to last week's question, "Taking The Odds" (October 1, 2018)

1-4%.