Inner Ear?

Because the apparatus that your body uses to maintain its balance (a series of fluid filled canals) is located in the inner ear.

ok but how is it disrupted?

Dunno. If I had to guess, I would say that inflammation in the inner ear puts pressur on the outsides of the tubes. Because the tubes function by monitoring small changes in pressure due to the displacement of the liquid inside, perhaps exterior pressures result in "false" signals to the part of your brain that monitors input from the tubes.

Or maybe the inside of the canals themselves get infected, though this seems less likely...

i never seemed to get that far in my studies with the next door neighbor.. she didnt like me messing with her ears, though.... thanks pati