Generation of Vertical and Torsional Rapid Eye Movement in the Rostral Mesencephalon: Experimental Data and Clinical Implications

The riMLF is a nucleus in the rostral mesencephalon whose bilateral destruction leads to a palsy of vertical and torsional rapid eye movements. A unilateral lesion leads to a loss of torsional rapid eye movements in only one direction, but vertical rapid movements can still be generated with some reduction in their velocity. Single neuron studies in monkeys and anatomy support the concept that the riMLF together with the PPRF are the critical areas in the brainstem to generate rapid eye movements in 3 dimensions.