Asymmetry in congenital ocular motor apraxia

A 10-month-old girl presented with apparently unilateral ocular motor apraxia (OMA). Electro-oculography confirmed an inability to generate a saccade for fixation or in response to an optokinetic or vestibular evoked stimulus to the right. Fixation and optokinetic saccades and vestibular evoked nystagmus were present to the left. Magnetic resonance imaging revealed a small cerebellar vermis but no localizing unilateral abnormality or tumour. Subsequent review of video recordings of 16 children with congenital OMA revealed that 5 demonstrated asymmetry in the generation of fixation saccades. Two of the five also demonstrated asymmetry of vestibular evoked nystagmus, and an additional child had optokinetic asymmetry.