Lateropulsion and upbeat nystagmus are manifestations of central vestibular dysfunction

An elderly man presented with acute onset of gait instability, characterized by leaning to the left while walking, vertigo, diplopia, and transient facial numbness. The examination was remarkable for ocular lateropulsion and primary position upbeat nystagmus. Computed tomography of the brain revealed a right-hemispheric cerebellar infarction. This report illustrates that lateropulsion can occur in cerebellar lesions, but that it may be contralateral to the cerebellar hemisphere involved. Primary position upbeat nystagmus and lateropulsion may represent forms of central vestibular dysfunction due to interruption of vestibulo-ocular pathways.