[Abnormal vergence eye movement during eyelid closure caused by a pineal tumor]

A case with abnormal eye movement induced by eyelid closure and selective paralysis of downward gaze was reported. CT scan and MRI imaging revealed a pineal tumor with bilateral involvement of the thalamomesenchephalic junctions without obvious damage to the posterior commissure. Histopathologically, the tumor was a germinoma. The pupillary light reflex was absent and near reflex was reduced. Lightning eye movement, skew deviation and convergence-retraction nystagmus were observed. The horizontal eye movement was normal in both eyes. The eye did not move downward below the level of direct forward gaze spontaneously or on attempted downward gaze. Downward vestibulo-ocular reflex was absent. Bilateral abnormal vergence eye movement with alternating convergence and divergence was observed during eyelid closure. The cycle of the abnormal eye movement was about 3Hz and there was no fast phase. The abnormal eye movement was not observed in the darkened room with both eyes open. After subtotal removal and radiation therapy of the pineal tumor, the abnormal eye movement disappeared.