Thanks for your query and an elucidate history.
I can understand that the vertigo
started with left middle ear infection
and started with treatment.
I think he needs to be well investigated by doing high resolution CT
scan of mastoids and MRI
of the brain. This can help a proper diagnosis.
The patient getting so unbalanced after ear infection is rare. There may be associated other problems too of brain like cerelellitis and so on..
IT is good that you are taking him to Pediatric Neurologist
Many times we get odd findings . There are really rare , yet to inform you. The patient may also be suffering from a generalized disease like malaria/ typhoid/ granulomatous disorders.. These also should be taken into account.
The Neurologist will be in a position to have a complete physical/ clinical evaluation , which is so much important in vertigo cases.
Young people per se get vertigo rarely.