アブミ骨底の瘻孔を伴つた耳性髄液漏の1例

CEREBROSPINAL FLUID OTORRHEA IHROUGH STAPES FOOT-PLATE FISTULA, A CASE REPORT

　I．はじめに

　耳性髄液漏（CSF-otorrhea）は二次感染により髄膜炎をひきおこすので，患者の生命に重大な危険を与える状態である。

　その原因としては，1）頭部外傷による側頭骨骨折，2）手術損傷，3）腫瘍，4）感染症，5）先天性異常などに大別されるが^9）19），このうち先天性異常に基ずくものはきわめて稀である。

　A 9 year-old girl with cerebrospinal fluid otorrhea who had repeated episodes of meningitis is reported. There was no history of trauma. Radiological examination revealed a large cystic dilatation of the vestibule and the lateral semi-circular canal, suggesting hypogenisis of the cochlea (Mondini Type).

　When the cystic wall of the vestibular space was surgically opened the cerebrospinal fluid gushing through the internal auditory meatus into the vestibule. With the removal of the stapes a fistula was found at the posterior-inferior margin of the foot-plate. And a direct communication between the fistula with the underlying vestibular cyst was ascertained.

　It is suspected, in our case, that there might have been a direct communication between the vestibular cyst and the subarachmoid space through the dehiscent internal auditory meatal wall. Consequently, CSF-otorrhea seemed to have occurred through this meatal wall into the stapes foot-plate fistula.