Mannitol-induced stria vascularis edema.

After administration of mannitol, an osmotic diuretic, edema of the stria vascularis occurs, which is morphologically indistinguishable from the stria edema observed after administration of loop-inhibiting diuretics. Similar edema also was observed after glycerin administration. Both mannitol and glycerin may act osmotically to draw fluid from the endolymph into the stria. Temporary improvement in the hearing level and discrimination from the glycerin test in endolymphatic hydrops could be explained by this potential mechanism of endolymph volume reduction.