Ocular Dipping and Ping-pong Gaze Due to Bi-hemispheric Strokes

This is a 51-year-old man presenting with hypertensive left thalamic intracerebral hemorrhage and intraventricular hemorrhage, with course complicated by multifocal supratentorial ischemic strokes. He developed abnormal movements characterized by slow, conjugate, horizontal deviations, consistent with ping-pong gaze. This likely represents a release phenomenon due to disconnection between the cerebral cortex and pontine horizontal gaze centers. Additionally, there were intermittent slow, conjugate downward movements with a fast return to primary position, consistent with ocular dipping. Likewise, this might be due to a disconnection between cerebral cortex/basal ganglia and midbrain vertical gaze centers. Our case extends the spectrum of potential causes of ocular dipping to include multifocal supratentorial lesions, in addition to the previously described more diffuse and symmetric bi-hemispheric processes, such as anoxic brain injury and Creutzfeldt-Jakob disease [1,2].