良性発作性頭位めまい症に対する耳石置換法について

抄録

　Effective canalith repositioning maneuvers for cases of Benign Paroxysmal Positional Vertigo (BPPV) - canalolithiasis are all characterized by head positioning via the healthy-ear-down 135° head position. The healthy-ear-down 135° head position is the key position that allows the dropped canaliths in the semicircular canal to easily fall back into the utricle. At present, there is no clear evidence to support the canalith repositioning maneuvers for BPPV - cupulolithiasis. The presumed reason is that the strength of adherence of the canaliths to the cupula is unknown, and it is often not apparent whether the canaliths adhere to the utricular or canal side of the cupula. The position and direction of the cupula can become a problem in cases of BPPV - cupulolithiasis. The cupula of the lateral semicircular canal is directed backward toward the outside. On the other hand, the cupulae of the posterior semicircular canal and anterior semicircular canal are directed backwards toward the upward direction. Therefore, in cases of BPPV - cupulolithiasis, a characteristic neutral position exists where the nystagmus disappears, because the direction of the heavy cupula is consistent with the direction of gravity. In this paper, I shall introduce the canalith repositioning maneuvers that I use (the Epley maneuver, the healthy-ear-down 135° maneuver, and the affected-ear-down 135° maneuver) and comment on the advantages and problems of each of these maneuvers.