Colliding at Dizzying Speed

Question:    An otherwise healthy 42 year old male is involved in a motor vehicle accident and sustains a right sided otic-capsule sparing temporal bone fracture.  Examination showed mild right beating nystagmus, hemotympanum, and normal facial nerve function.  He is hospitalized for several days to recover from other traumatic injuries and suffers from persistent vertigo associated with headache, nausea, and amnesia.  What is the most likely etiology of his vestibulopathy?  [Answer will be posted with next week's new question]

Answer to last week's question, Know Your Hormones (December 14, 2015): 

Hungry Bone Syndrome.  The sudden drop in PTH to normal physiologic levels results in a reversal of the rapid bone turnover caused by high PTH levels.  This can result in severe and prolonged hypocalcemia, tetany, and cardiac dysrhythmias.