下向性垂直性眼振症例

ONSET OF VERTICAL NYSTAGMUS ON LOOKING DOWN

　I．はじめに

　注視に際し上向きあるいは下向きに発現する注視眼振はしばしば経験するところであるが，自発性に解発する垂直性眼振は稀な現象とされており，本邦における報告でも数例をみるに過ぎない。私どもは今回自発性の下向性垂直性眼振のみられた症例を経験したのでその概略について報告する。

　A woman, aged 27, complained of vertical nystagmus when she opened her eyes and looked downwards. This symptom disappeared altogether when the patient closed her eyes or looked upwards. With a body balance test balance disturbances were seen when the eyes were directed downwards but, no change occurred when the eyes were directed upwards.

　Examination showed disturbances in the function of the tenth and twelfth cranial nerves on the right side and X-ray examination with cranial vascular visualization showed some changes in the basialar artery.