良性発作性頭位めまい症

抄録

　Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vertigo and is characterized by brief attacks of rotatory vertigo associated with positional and/or positioning nystagmus, which are elicited by specific head positions or changes in head position relative to gravity. The pathophysiology of BPPV is canalolithiasis comprising free-floating otoconial debris within the endolymph of a semicircular canal, or cupulolithiasis comprising otoconial debris adherent to the cupula. In the canalolithiasis theory, when patients with BPPV move their head, free-floating otoconial debris in the canal creates the endolymph flow, the flow of the fluid causes deflection of the cupula of the canal, and as a result, the canal is stimulated or inhibited and nystagmus and vertigo are induced. In the cupulolithiasis theory, when patients with BPPV move their head, the cupula, with its adherent otoconial debris, deviates in the direction of gravity, and as a result, the canal is stimulated or inhibited and nystagmus and vertigo are induced.

　 In this review, we provide the classification, diagnostic criteria for BPPV published by the Japan Society for Equilibrium Research and the Bárány Society. The diagnostic criteria for BPPV published by the Bárány Society are part of the International Classification of Vestibular Disorders (ICVD)-an endeavor for classification of vestibular disorders steered by the Committee for Classification of Vestibular Disorders of the Bárány Society. In the two diagnostic criteria, canalolithiasis of the posterior canal, canalolithiasis of the lateral canal, and cupulolithiasis of the lateral canal have been accepted as BPPV, but the other variants of BPPV, such as canalolithiasis of the anterior canal, cupulolithiasis of the posterior canal, lithiasis of multiple canals, etc., have been classified into emerging and controversial syndromes or an atypical type.