Disconjugate eye movements during electronstagmographic testing in patients with known central nervous system lesions

A tacit assumption underlying current ENG testing is that the eyes move conjugately. However, considering the intricate neuroanotomical pathways within the ocular motor system in addition to the elaborate vestibulo-ocular connections, we think it reasonable that disconjugate eye movements may result with certain CNS lesions. Recently we have employed independent eye movement measuring techniques in order to assess the movement of each eye separately during our ENG valuations. The preliminary work has revealed that disconjugate eye movements occurred even with extra-axial lesions which spared the medial longitudinal fasciculus. These data may be valuable for the neurotologist with regard to differential diagnosis and prescription of a treatment plan for the patient. The eye movement patterns of patients with confirmed CNS lesions and other interesting findings are presented.