異常眼球運動―ｏｐｓｏｃｌｏｎｕｓとｆｌｕｔｔｅｒ‐ｌｉｋｅ ｏｓｃｉｌｌａｔｉｏｎ―の１症例

Abstract

A 67-year-old woman noticed tremor of her hand and jerking of her eyeballs on May 20, 1986, and then became unable to stand. The cerebrospinal changes and Magnetic Response Imaging (MRI) findings were compatible with encephalitis. She was treated with decadron, and the tremor and ocular oscillations gradually decreased.The abnormal ocular movements which were recorded by electro-oculography (EOG) on June 24, revealed frequent, irregular, rapid, multidirectional conjugate ocular oscillations (so-called opsoclonus) with the eye open or closed. These ocular oscillations were suppressed with Frenzel's spectacles. Gradually, the vertical components of the opsoclonus decreased. On June 26, in addition to the opsoclonus, pendullar oscillation consisting of approximately equal amplitude (so-called flutter-like oscillations) developed. The small ocular oscillations similar to flutter like oscillation were recorded by EOG and a fine intension tremor was still present after recovery. The latency of the saccade was prolonged by interruption of the abnormal ocular movements.It seems that the opsoclonus and flutter-like oscillation in this patient represented tremor of the eyeballs caused by a disorder of the burst cells in the brain stem saccadic control system in addition to a disturbance of the cerebellar dentate nuclear system.