Abstract:ObjectiveTo determine the influence of illness duration on the outcome of posterior semicircular canal benign paroxysmal positional vertigo (PCBPPV).Methods428 patients suffering from primary PCBPPV treated by Epley or Li’s repositioning maneuver from Oct 2009 to Nov 2017 were included. of them, 155 were male and 273 were female. They ranged in age from 16 to 89 years old with a median age of 53, and their illness duration ranged from half a day to 7 years with a median of 7 days. According to the timepoints of illness duration, all patients were divided into shortterm group, mediumterm group, medium and longterm group as well as longterm group. The therapeutic outcomes at the third day and seventh day of repositioning therapy were recorded and analyzed.ResultsThe effective rates of the shortterm group, mediumterm group, medium and longterm group, and longterm group at the third day were 94.55%(208/220), 90.80%(132/147), 86.27%(44/51), and 90.00%(9/10),respectively. Those at the seventh day were 97.73%(215/220), 97.28%(143/147), 96.08%(49/51), and 100%(10/10). The differences of outcomes in all the four groups between the two timepoints were statistically insignificant(all P>0.05).ConclusionsThe illness duration and selfcure of PCBPPV may not affect its shortterm outcome with repositioning maneuver. Age may cause difference in selfcure of PCBPPV.