4.良性発作性頭位めまい症BPPV―後半規管型BPPV

Abstract

Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vestibular disorder. Although it is easily cured with physical therapy such as a canal repositioning procedure (CRP), intractable BPPV patients show relapses or poor response to physical therapy. Anatomic variations, stenoses in the membranous labyrinth of the semi-circular canal (SCC), or multiple clots of particles in the SCC, and the short-arm type BPPV are related to intractable BPPV. Other backgrounds related to intractability in BPPV have been reported including osteoporosis, head trauma, position during bed rest, Ménière's disease, and sudden sensorineural hearing loss. Appropriate management of intractable BPPV requires the correct diagnosis. The background of BPPV hold the key to the diagnosis of intractable BPPV. Differential diagnosis of the common cause between long-arm type BPPV and short-arm type BPPV becomes very important, with particular attention required to check the duration and characteristics of positional nystagmus. The positional nystagmus during CRP allows speculations on the movement of debris and the appropriate treatment strategy. Physical therapy for intractable BPPV may be based on release of the otoconial debris, and transfer and fixation of the debris to the utricle.