Serum osmolality in Menière's disease.

Serum osmolality in patients with Meniere's disease was measured by a Wescore 5100B osmometer to reveal the relationship between a vertiginous attack, the effect of isosorbide, the effect of glycerol, and the osmolality. The following results were obtained: First, the osmotic pressure of the control group ranged from 275 mOsm/kg to 285 mOsm/kg, and that of the Meniere's group ranged from 270 mOsm/kg to 290 mOsm/kg. Both groups showed normal distribution, and mean values of both were 284 mOsm/kg. There was no statistically significant difference between them with regard to serum osmolality. Second, patients with values of 283 mOsm/kg or less were more often in a vertiginous attack period, and patients with values of 284 mOsm/kg or more were more often in an attack-free period. Third, patients with values of 283 mOsm/kg or less were more often in the positive glycerol test group; those with values of 284 mOsm/kg or more were more often in the negative glycerol test group. Finally, there was no significant difference in serum osmolality between patients receiving isosorbide therapy and patients given no treatment.