Roving Eye Movements
Roving eye movements consist of slow drifting movements of the eyes from side to side; the eyelids are closed and there may be slight divergence of the ocular axes. Roving eye movements may be seen in normal sleep, but also in comatose patients in whom they are indicative of an intact brainstem (e.g., the early diencephalic stage of central herniation) but are otherwise nonlocalizing . As coma deepens, roving eye movements are lost before the movements provoked by the oculocephalic (doll’s head) maneuver (oculocephalic reflexes, vestibulo-ocular reflexes), or the caloric tests. Roving eye movements cannot be mimicked, hence their presence excludes psychiatric coma or pseudocoma.