Computerized tomography in central nervous lesions and disturbances in the oculomotor system

Of the central nervous disorders observed neurotologically from 1975-77, 41 cases-midbrain diseases, pontine tumors, cerebella-pontine angle tumors, acoustic neurinomas, cerebellar diseases and IV venticular tumors-were topographically diagnosed, and we investigated the influence on the oculomotor system and localization of the lesions. In case of midbrain diseases, abnormality of vertical OKN was noted in all cases, indicating the definite difference from abnormality of horizontal OKN. Marked disturbance by gaze nystagmus test, OKN and ETT in particular severe disturbed horizontal eye movement were observed in cases of pontine tumors. The cerebellopontine angle tumors and acoustic neurinomas showed 60 to 80% abnormality in all tests. Many cases of cerebellar diseases indicated saccadic pursuit pattern on the eye tracking test. Hereafter, by means of computer analysis of experimental nystagmus test as well as further detailed observation of basic nystagmus responses, neurotological findings together with usefulness of CT-scan on topographical diagnosis may enhance the possibility of early diagnosis and topical diagnosis.