Time series analysis of the course of Menière's disease.

Subjective symptoms of Menière's disease (vertiginous attacks, nonparoxysmal dizziness, tinnitus, hearing loss, headache, stiff neck, nausea etc.) were graded respectively according to severity (0-3 or 0-5) and were recorded daily by affected patients. These recordings, from 20 cases of Menière's disease, were collected and analysed by an original program of time series analysis including autocorrelation, cross-correlation, daily sum of inner ear related factors and general factors, and their moving average. Cluster occurrence of dizzy spells in the active stage and a marked cross-correlation between inner ear factors and general factors were found to constitute a characteristic pattern in Menière's disease in relation to its pathophysiology. Time series analysis was also useful for clinical decision-making, such as evaluation of the effect of treatment, and estimation of prognosis.