抄録
The histopathology of a case of an extremely underdeveloped facial nerve in the Fallopian canal is described. 4 temporal bones of 3 cases of severely damaged facial nerve by congestion are also decribed. The major finding of the former was that the facial nerve ended in the tympanic segment but no abnormality was found in the middle and inner ear structures. In documented, underdeveloped facial nerve cases, including our present case, 6 out of 8 showed that the facial nerve end in the horizontal segment. As for the latter, the major findings of all 3 cases are that there were severe hemorrhages in the Fallopian canal and the destruction of the facial nerve begins in the horizontal segment with the presence of perineurium. From these facts, the system of the blood vessels of the Fallopian canal below the tympanic segment is different from that of the system above it, and the facial nerve bellow this level is presumed to be vulnerable to damage through blood flow disturbances.
