術前に予測できなかった稀な部位からの耳性髄液漏症例

抄録

Congenital otorrhea of cerebrospinal fluid (CSF) is usually accompanied by Mondini-type inner ear malformation, in which CSF leaks through the oval window. It is very difficult to find CSF fistula when CSF leaks through outside the oval window. The first case was a 5-year-old boy who developed recurrent meningitis twice a year. Neither audiogram nor tympanogram showed abnormal findings bilaterally. CT scan of the temporal bones and MR-hydrographm demonstrated a little effusion in the right mastoid, but neither evidence of CSF leakage nor bony defect. However, RI-cisternography revealed an abnormal accumulation of radioisotope in the right middle ear, thus he was diagnosed as leakage of CSF. Exploratory tympanotomy of the right ear uncovered a bony defect just inferior to the fallopian canal, suggesting CSF fistula at the region of the geniculate ganglion. The second case was a 6-year-old girl who had suffered from Langerhans cell histiocytosis, developed bacterial meningitis twice. Audiogram revealed right deafness and CT scan of the temporal bones showed right common cavity malformation. RI-cisternography revealed no abnormal accumulation of radioisotope. Although there was no sign for CSF otorrhea, exploratory tympanotomy of the right ear disclosed a little amount of CSF leakage through the Hyrtl's fistula.