Abstract
A case of Louis-Bar's syndrome (ataxia telangiectasia) in a 9-year-old girl was presented and * study was made of the nature and origin of oculomotor abnormalities in association with the syndrome.
1. Nature of the oculomotor abnormalities
The following abnormalities were observed: 1) hypometric saccades; 2) difficulty of keeping eye position (notably non-central gaze); 3) coarse fixation jerks; 4) downward vertical nystagmus elicited on lateral gaze; 5) weak convergence; 6) suppression of optokinetic nystagmus; 7) disturbance of smooth following eye movements; 8) Roth-Bielschowsky sign; 9) flutter-like oscillations of the eye (Cogan). In addition to these, fixation nystagmus is also reported in the literature. To be noted is that the symptoms 3), 7) and 9) are entirely new additions to the ocular manifestations of this syndrome.
2. Origin
Aside from these oculomotor abnormalities, conspicuous cerebellar symptoms were the only neurologic manifestations in the present case. Along with recent demonstration that the pathology of the central nervous system of the syndrome is characterized by diffuse atrophy occurring almost within the confines of the cerebellum or at least by the absence of significant lesions in the brain stem and cerebrum, it was suggested that the oculomotor abnormalities mentioned above are all of cerebellar origin. In this connection, special reference was made to the symptoms 5), 6), 8) and 9).
