Ocular Dipping in Anoxic Brain Injury

This Video illustrates the clinical finding of ocular dipping in a woman with anoxic encephalopathy following cardiac arrest. Ocular dipping comprises slow downward movement of gaze followed by rapid return to primary position; also shown is superimposed spontaneous conjugate roving horizontal eye movements, which are often present. The finding is most commonly reported in the setting of severe anoxic brain injury with associated diffuse cortical and lenticular pathology but has also been described in prolonged status epilepticus and prion disease. The mechanism is uncertain but may involve dysfunctional cortical/lenticular connectivity with rostral brainstem vertical gaze centers and arousal pathways. Prognosis for patients is variable.