頭部外傷後の発作性頭位めまい症の２症例 方向交代性頭位眼振の検討

Abstract

In 1962, Schuknecht reported that cupulolithiasis in the posterior semicircular canal caused by the otoconia detached from the otolithic membrane in the utricular macula was a possible cause of positional vertigo of the benign paroxysmal type (BPPV). In 1996, we reported that basophilic deposits adhered to the cupula in not only the posterior semicircular canals but also in the lateral and anterior semicircular canals. It is very interesting to evaluate the kinds of nystagmus caused by the cupulolithiasis and canalolithiasis in the lateral and anterior semicircular canals.In this study, the origin of direction changing positional nystagmus in the upper ear found in cases of benign paroxysmal positional nystagmus (BPPN) after head trauma was investigated. The subjects included two paients with direction changing positional nystagmus to the upper ear with BPPN after head trauma treated at the Neuro-otological clinic, Kitasato University Hospital between 1985 and 1996.It was suggested that the origin of this type of nystagmus as well as the various other types of nystagmus observed during their respective clinical courses was cupulolithiasis or canalolithiasis in the lateral semicircular canal and/or posterior semicircular canal.Although it was suggested that direction changing positional nystagmus from the upper or lower ear was caused by central vestibular disorder, especially that in the vermis, it was lil; ly that one case in this series was also caused by peripheral vestibular disorder.