my son is 8 years old, has complained about dizziness or light-headedness for the past week. We took him to the ER, checked him out neurologically, ekg, blood, and all seems fine. The dizziness comes and goes, throughout the day, not severe, but like he has just got off a spinning ride. We were on a cruise up through the 28th of April, and he was fine then and when we got off the ship. About a week later, these symptoms started. What could it be?