Sylvian aqueduct syndrome. Chronology of tumors in the pineal region in view of ocular movement.

We experienced 21 cases of tumors (13 of pinealoma of the two-cell pattern and eight of tumors originating from the posterior part of the third ventricle). We carefully observed the eye movements of these patients during their respective clinical courses and found changes in abnormal eye movements along with remission following cobalt irradiation therapy or ventriculo-peritoneal shunt as well as with relapse on recurrence of tumors. From the neurotological viewpoint, we divided the development of these abnormal eye movements into four chronological stages. We emphasized the importance of the early diagnosis of tumors manifesting Sylvian aqueduct syndrome. Careful observation and analysis of eye movement will be a great help in making diagnoses as well as decisions for further examination and treatment.