@article{oai:sapmed.repo.nii.ac.jp:00008101,
 author = {北條, 敦史 and 福岡, 誠二 and 高梨, 正美 and 小西, 正訓 and 中村, 博彦},
 issue = {1},
 journal = {北海道脳神経疾患研究所医誌 = Journal of Hokkaido Brain Research Foundation},
 month = {Mar},
 note = {Object: Functional outcome in patients with vestibular schwannomas (VS) treated by gamma knife (GK) has been reported to be excellent, as well as tumor control. Although, VS is originated from the vestibular nerve, the reports for vestibular function have been rare so far. But in patients with VS, the dizziness after GK is very uncomfortable symptoms and sometimes affects on ADL of aged patients. We analyzed vestibular function in consecutive 56 cases of VS prospectively before and after GK. Methods: The tumors, ranging from 0.01 - 8.5ml (mean 2.3ml), were treated with GK of marginal dose of 10-13Gy (mean 12Gy) . The vestibular function was evaluated with caloric test, vestibular evoked myogenic potential (VEMP), and stabilometry (Total length, Marginal area) . We also neurologically examined extraocular movement, stepping test, one foot standing test, and arm deviation test before GK. Results: Thirty-nine out of 56 (70%) patients had history of dizziness. Twenty-two patients complained dizziness before GKRS. After treatment, dizziness disappeared in 12 out of 22 (55%) patients, unchanged in 34 out of 56 (61%) patients, and dizziness deteriorated or newly appeared in 10 out of 56 (18%) patients then recovered in 8 out of 10 (80%) patients. In 2 out of 56 (3.6%) patients, dizziness worsened persistently. Positive rates of caloric test before GK, at 1, 6, 12 mos. after GK were 75, 65, 72, 38%, respectively. Positive rates of VEMP before GK, at 6mos. after GK were 36, 29%. Positive rates of caloric test and VEMP were not different statistically before and after GK. Total length and marginal area of stabilometry were almost same value before and after GK. Neurological positive rates of saccadic eye movement, stepping test, one foot standing test, arm deviation test were 93, 81, 89, 91% before GK. Conclusions: Major part of patients were found to have neurologically vestibular dysfunction. GK dose not remarkably affect on the symptoms of dizziness and the vestibular function in patients with VS. Major part of patients who developed dizziness (new or deteriorated) after GK would recover. Stabilometry seems to be a good tool to evaluate dizziness before and after GK.},
 pages = {7--13},
 title = {聴神経腫瘍の前庭機能評価 : ガンマナイフ治療前後の検討},
 volume = {13},
 year = {2003}
}