We treated 44 cases of vestibular Meniere's disease with prostaglandin I2 (PGI2), a vasodialator, at a dose of 120,ug per day for more than two months (mean: 8.0 months). The long-term administration of constant daily amounts of PGI2 attained good long-term results in vertigo according to the criteria of the Japan Society for Equilibrium Research. The results were as follows: the administration of PGI2 completely controlled vertigo in 65.9% (29/44) and improved it in 29.5% (13/44); however,

more »

... cases suffered from the typical type of Meniere's disease thereafter (9.1%: 4/44). The objective findings of nystagmus were also reduced in 85.7% (24/28) after PGI2 treatments. PGI2 was significantly more effective in patients with a vertigo duration within 120 min and -SP/AP negative results on electro-cochleogram (ECoG) than the others . On the contrary, patients with a vertigo duration of more than 120 min and -SP/AP positive results on ECoG experienced cochlear symptoms together with vertiginous sensations later. These patients should be treated with an oral osmotic diuretic, isosorbide. These findings suggest that cases presently diagnosed as vestibular Meniere's disease could include at least two kinds of oto-pathologies; vascular disease and endolymphatic hydrops.