Evidence for three-dimensional cortical control of gaze from epileptic patients
- 1Department of Neurology, University Hospitals Case Medical Center, Cleveland, Ohio, USA
- 2Daroff-Dell’Osso Ocular Motility Laboratory, Louis Stokes Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA
- 3Department of Neurology, Royal Prince Alfred Hospital, Sydney, NSW, Australia
- Dr M J Thurtell, Department of Neurology, University Hospitals Case Medical Center, 11100 Euclid Avenue, Cleveland, OH 44106, USA; mj.thurtell{at}gmail.com
- Received 4 June 2008
- Revised 16 July 2008
- Accepted 28 August 2008
Abstract
Electrophysiological studies in primates indicate that the eye fields of the cerebral hemispheres control gaze in three-dimensional space, and contain neurons that encode both conjugate (versive) and vergence eye movements. Two patients with epilepsy who exhibited disconjugate contraversive horizontal eye movements are described, one during electrical stimulation of the frontal eye fields and the other during focal seizures. We postulate that these eye movements resulted from combined contralateral version and vergence, and suggest that human cortical eye fields also govern visual search in a three-dimensional world, shifting the point of fixation between targets lying in different directions and at different depths.
Footnotes
-
See Editorial Commentary, p 585
-
Funding: Supported by NIH grant EY06717, the Office of Research and Development, Medical Research Service, Department of Veterans Affairs, and the Evenor Armington Fund.
-
Competing interests: None.
-
Ethics approval: Ethics approval was obtained.
