Teaching Video NeuroImages: Alternating skew deviation with abducting hypertropia following superior colliculus infarction

摘要

A 63-year-old patient was admitted with acute ataxia and binocular oblique diplopia. Neuro-ophthalmologic examination revealed abducting hypertropia on lateral gaze, better seen during upgaze, mimicking bilateral inferior oblique palsy (video, figure). There was no ocular cyclotorsion. Brain MRI revealed focal ischemic lesions in the right cerebellar hemisphere and left superior colliculus (figure). The diagnosis of alternating abducting hypertropic skew deviation was made. This rare type of skew deviation is related to central otolithic dysfunction. Similar cases have been described with cerebellar, pretectal, or cervico-medullary junction lesions.(1,2) Orthoptic management can help and patients can slowly improve over months.