Paroxysmal positional vertigo revisited: is it benign, pseudo-benign or malignant?
Abstract
Dix and Hallpike firstly described Benign Paroxysmal Positional Vertigo(BPPV) in 1952. Since then, this disease have been widely recognized among clinicians. There are some charactstic symptoms such as, having critical head position, being pure rotatory nystagmus with the phenomenon of crescendo and decrescendo, having fatigue phenomenon on provocation of the vertiginous attack.. Pathogenesis of the BPPV is explained by the dysfunction of otolith in a inner ear.
Pseudo-BPPV firstly described by present authors about 25 years ago. Symptoms are characterized by closely resembled to that of BPPV. It is a pure rotatory counter-rolling positional or positioning nystagmus with a latent period. We also have found less fatigability of the provoked vertiginous attacks. The pathological lesion located in cerebellar vermis and the nature of pathology is all cerebellar infarction.
Among Paroxysmal Vertigo, there is a type of vertigo with vertical nystagmus. This vertiginous attack can be provoked by positional or positioning test repeatedly showing no fatigue phenomenon. Lesion of the malignant type is also located in cerebellar vermis but the nature of the pathology is different from that of Pseudo-BPPV.
Diagnosis of the PPV is important for the treatment. Most of the patient of the BPPV are elderly, therefore, procedures of the replacement therapy may increase the risks to provoke iatrogenic cerebrovascular disorders