Both the Lutz and Cogan classifications of INO separate them into anterior and posterior varieties. The Cogan classification, which depends upon the presence or absence of convergence, is not particularly useful for localization. The Lutz posterior INO, which is a supranuclear pareses of abduction, is exceptionally rare.
Robert B. Daroff, MD, Professor of Neurology, School of Medicine, CASE Western Reserve University, University Hospitals - Case Medical Center
Spencer S. Eccles Health Sciences Library, University of Utah