How would one diagnose a peri lymph fistula?

Difficult diagnosis: Perilymphatic fistula is an infrequent complication of head injury, heavy lifting, or barotrauma in which a fistula develops at the otic capsule. Sneezing, lifting, straining, coughing, and loud sounds may cause episodic vertigo or hearing loss. Most diagnostic tests are insensitive, but ct of the head may help. Bed rest, head elevation, and avoiding straining are conservative treatment measures.