The Caloric Test In Idiopathic Benign Paroxysmal Positional Vertigo

ObjectivesTo make an analysis of caloric test results in 112 patients with Idiopathic BPPV for finding some characteristics of vestibular funtion examination in BPPV so as to make a further understanding of possible pathogenic mechanism.MethodsForm 2006 to 2010 in our clince,112 vertigo patients were diagnosed as idiopathic BPPV patients,91 cases of posterior semicircular canals BPPV(PC-BPPV),19 horizontal semicircular canals BPPV(HC-BPPV) and 2 anterior semicircular canals BPPV(AC-BPPV).A detection of alternate binaural caloric test(CT) was performed in these patients.With canal paresis(CP) as evaluation parameter ,an analysis was made of the difference in examination of caloric test for the two types of BPPV in both PC-BPPV and HC-BPPV to study the possible cause and mechanism in the difference .RustlesOf 91 PC-BPPV patients,26 canal paresis(CP) were found on abnormal side and 14 on normal side.The incidence of CP on abnormal side of PC-BPPV is higher than that on normal side .The difference in both of them is of statistical significance. Of 19 HC-BPPV patients, 10 CP were found on abnormal side and 1 on normal side.The incidence of CP on abnormal side of HC-BPPV is higher than that on normal side.There is an abvious difference between them and it is of statistical sifnificance .In PC-BPPV,26 CP cases were on abnormal sides and in PC-BPPV,10 CP cases were on abnormal side.The incidence of CP on abnormal side of HC-BPPV is higher than that of PC-BPPV.The difference between them has statistical significance.ConclusionThe incidence of CP on abnormal side of PC-BPPV and HC-BPPV is higher than that on normal side. The incidence of CP on abnormal side of HC-BPPV is higher than that PC-BPPV. The floaing otolith in semicircular canals make the change of endolympha density and brings abou dynamic of endolympha ,which may be one of the causes of the abnormality in the temperature test.In addition to floating otolith, there may be extensive pathologic change in the vestibular peripheral system. A combination of caloric test,head shaking test and vestibular autorotation test may contribute to an overall evaluation of the vestibular function.