オリーブ橋小脳萎縮症の神経耳科学的検討

Abstract

The main clinical findings of OPCA include cerebellar symptoms, extrapyramidal symptoms, autonomic nerve symptoms, in addition to various oculo-motor disturbances. We reported a case of OPCA where neuro-otological examination facilitated the diagnosis. Neuro-otological examination was carried out in 6 cases of OPCA, and duration of illness and experimental findings were compared.Subject: Neuro-otological examination was undertaken in 6 OPCA patients over a 5 year period 1993-1997. The mean patient age was 53.8 years, and the ratio of males to females was 2:4. Duration of illness was 3 years for 2 patients, 4 years for 2 patients, 6 years for 1 patient and 8 years for 1 patient.Method: For all patients, the following examinations were carried out. (1) audiogram, ABR (2) nystagmus (3) eye tracking (4) optokinetic nystagmus, saccade (5) visual suppression.Results: Smooth pursuit eye movement impairment was independent of the duration of illness. Nystagmus findings, saccadic eye movement and the visual suppression test revealed that impairment increased in patients whose duration of illness was more than around 4 to 6 years. The oculo-motor disturbances of OPCA start with impairment of cerebellar and smooth pursuit eye movement, and eventually result in brainstem disorders such as saccadic eye movement and visual suppression. As the duration of illness lengthens, the oculo-motor system itself will no longer function and response to all of the examinations will be lost. Neuro-otological examinations were found to be valuable for the diagnosis of OPCA.