Isolated paralysis of downward gaze is not very common. Only six cases have been reported with pathological anatomic findings since Andre-Thomas described the first case with autopsy.
A 47 year-old male with isolated paralysis of downward gaze was studied. In the neuro-otological examination, although doll's eye phenomenon of downward eye movement was preserved, neither optokinetic nystagmus nor smooth pursuit eye movement were present in the downward direction.
In the six cases that been described with autopsy, bilateral focal infarcts of the rostral mesencephalon were observed.
In this case, however, there were no abnormal findings in the rostral mesencephalon, though there were bilateral focal infarcts of the thalamus on CT scan. However, it is difficult to explain in the relationship between the isolated paralysis of downward gaze and the findings on the CT scan.
