[Congenital oculomotor apraxia with corpus callosum agenesis and subtentorial atrophy].

A 7 year-old child with congenital oculomotor apraxia (Cogan's syndrome) presented with mainly voluntary horizontal saccadic movements. Fixation of a visual target could be obtained only by a sudden movement of the head preceded by eyelid blinking. Electro-oculography confirmed the predominant disturbance of saccadic movements (delay in onset, hypometria). CT scan showed agenesis of the corpus callosum and atrophy of the vermis together with enlargement of the 4th ventricle and pre-pontine cisternae. The role of these anomalies in the pathogenesis of this rare congenital syndrome of good prognosis is discussed.