Sustained upgaze in coma.

Coma with sustained upward gaze deviation followed cardiac arrest in 15 patients and prolonged systemic hypotension in 2 patients. Neuropathological examinations confirmed the expected diffuse cerebral and cerebellar damage with relative sparing of the brainstem. No focal lesions were found in the upper midbrain or pretectum. Six patients developed slow, downward-beating nystagmus as the forced upward gaze resolved. Four of 6 patients with posthypoxic facial myoclonic jerks demonstrated synchronous upward gaze movements. Forced upgaze in come usually is the result of severe hypoxic encephalopathy. While anatomical localization is obscure, this sign does not indicate a structural lesion in the pretectum or midbrain and may result from damage to cerebellar pathways.