CONCLUSIONS: This study demonstrates that the resolution period of spontaneous nystagmus (SN) may provide an indication of vestibular dysfunction on a particular day in the primary care setting. OBJECTIVE: We aimed to predict canal paresis using fundamental observations of SN during the early stage of acute peripheral vestibular disorders. METHODS: The study involved 87 patients who had recently experienced their first episode of acute spontaneous vertigo and direction-fixed horizontal nystagmus. Although they did not exhibit any other neurological deficits, they had been hospitalized with severe acute symptoms between 2004 and 2007. A correlation between the resolution period of SN and the results of laboratory caloric testing was reviewed. RESULTS: The receiver operating characteristic analysis showed that the resolution period of SN may be a predictive indicator of unilateral vestibular hypofunction in the acute stage. In about half of the patients, SN disappeared on the third day after their initial visit. However, in 20% of the patients SN still persisted on the eighth day. Among the patients with SN, the prevalence of canal paresis increased with the increase in the resolution period of SN. When SN was observed on the fifth day, the prevalence was approximately 70%.
CONCLUSIONS: This study demonstrates that the resolution period of spontaneous nystagmus (SN) may provide an indication of vestibular dysfunction on a particular day in the primary care setting. OBJECTIVE: We aimed to predict canal paresis using fundamental observations of SN during the early stage of acute peripheral vestibular disorders. METHODS: The study involved 87 patients who had recently experienced their first episode of acute spontaneous vertigo and direction-fixed horizontal nystagmus. Although they did not exhibit any other neurological deficits, they had been hospitalized with severe acute symptoms between 2004 and 2007. A correlation between the resolution period of SN and the results of laboratory caloric testing was reviewed. RESULTS: The receiver operating characteristic analysis showed that the resolution period of SN may be a predictive indicator of unilateral vestibular hypofunction in the acute stage. In about half of the patients, SN disappeared on the third day after their initial visit. However, in 20% of the patients SN still persisted on the eighth day. Among the patients with SN, the prevalence of canal paresis increased with the increase in the resolution period of SN. When SN was observed on the fifth day, the prevalence was approximately 70%.