[A vestibular model of the course of Menière's disease].

Based on directional preponderance (DP) of the caloric nystagmus of 36 patients with Ménière's disease (MD), 57 calorigrams are divided in three groups: with ipsilateral, contralateral and without DP (neutral). Each calorigram is an unique moment in the course of MD. The age of the patient at that moment, the time since the first symptoms and since the last vertiginous spell, as well as the percentages of caloric response reduction and of DP are recorded. There are significant (Mann-Whitney U-test) differences between duration of the MD, time since the last spell and DP of the ipsilateral group and the same items of the contralateral group. Ipsilateral and contralateral calorigrams become neutral, consequently the neutral group is complex. From a vestibular point of view, MD is characterized by stages with a cyclic interrelation: during the first four years, ipsilateral stages with periferal stimulation or reversible reduction with recovery; one year after the first symptoms, contralateral stages with (partial) loss of function with central compensation; neutral stages--with or without minor spells--without further loss of function. Staging MD is of diagnostic importance; perhaps different stages need a different therapy. Stimulation or reversible loss of function in an ipsilateral stage is probably not caused by hydrops; in a contralateral stage with definite loss of function hydrops could be involved.