Abnormal vertical eye movements in the locked-in syndrome

As a rule, vertical ocular movements are thought to depend on mesencephalic structures, horizontal gaze on pontine structures. The ocular motility examination of a patient with pontine hemorrhage and no lession of the mesencephalon showed bilateral palsy of horizontal gaze and a dissociated loss of vertical movements: saccades were slowed, while pursuit managements were unchanged. The findings suggest that the pontine reticular formation is necessary in generation of normal vertical ocular saccades.