Imaging of ocular lateropulsion

Abstract

A 43-year-old man was admitted to Shin-Oyama City Hospital, Tochigi, Japan, with vertigo. Neurological examination showed body lateropulsion to the right, decreased thermal sensation in the right side of the face and left trunk including extremities. He did not show Horner syndrome, curtain sign or limb ataxia. Muscle strength and tonus were normal in all extremities. Both pupils were 3 mm. Spontaneous rotatory nystagmus to the left was seen. His eyes were deviated to the right, although he could keep his eyes midposition (Fig. 1a). Eye movements were full, but the eyes deflected to the right while upward saccades. Horizontal conjugate gaze deviation was detected when the eyelid was forcibly opened without warning (Fig. 1b), and on computed tomography under the instruction of eyelid closure (Fig. 1c). After slow blinking, the eyes immediately returned from the right side to mid-position. A right lateral medullary infarction was evident on the second day (Fig. 1d).In lateral medullary infarction patients, ocular lateropulsion refers to tonic horizontal conjugate gaze deviation to the lesion side, which is accentuated under eyelid closure or without fixation; full range of eye movement; asymmetrical amplitude of horizontal saccades; and vertical saccades deflect to the lesion side.1-3 In the present case, the olivocerebellar pathway was likely to be interrupted by the lateral medullary infarction. The pathway that originated in the contralateral inferior olive, after crossing midline, runs in the inferior peduncle to the cerebellar vermis. 2,3 AcknowledgmentThe authors declare no conflict of interest. References