In order to investigate whether the long-term prognosis of postoperative facial nerve function might be predicted by the analysis of facial nerve function in the early stage after the operation, we conducted sequential evaluations of facial nerve function in 51 cases of unilateral acoustic neuroma. The operation was conducted through the extended middle cranial fossa approach, and facial nerve function was evaluated by the modified Yanagihara's grading system (40 points Japanese grading system) at 6 points of postoperative time course, 5 days, 15 days, 1 month, 3 months, 6 months and over 1 year. Based upon the facial score in the 40 point Japanese grading system, facial nerve function was classified into 5 degrees, such as normal (40 points), excellent (over 30 points, below 40 points), moderate (over 20 points, below 30 points), poor (over 10 points, below 20 points) and severe (below 10 points). And the time course of degree of postoperative facial nerve function was analyzed.
The results obtained were as follows;
1) Eight cases, whose function was evaluated to be normal immediately (5 days) after the operation showed no subsequent facial palsy.
2) Six cases whose function was evaluated as excellent immediately after the operation, recovered to normal function at 3 months after tumor removal.
3) Seven of Eight cases whose function was evaluated as moderate immediately after the operation, recovered to normal function at 6 months after tumor removal.
4) Seven of fourteen cases in the excellent or moderate groups immediately after the operation showed a temporary deterioration of facial function 15 days after the operation, however, its function improved to normal except one case during the follow-up period.
5) The recovery of facial palsy was delayed in twenty-eight of twenty-nine cases whose function was evaluated as poor or severe immediately after the operation and did not recover to normal function during the follow-up period.
6) These results conclude that the facial nerve function immediately after tumor removal enables us to differentiate cases with an excellent long-term prognosis from others, and furthermore, it could be helpful in predicting the required time for the recovery to the normal function in the cases of excellent long-term prognosis.
抄録全体を表示