Applied Psycholinguistics (1985) 6, 205-230 Printed in the United States of America Review of agraphia and a proposal for an anatomically-based neuropsychological model of writing DAVID P. ROELTGEN, M.D. Department of Neurology, University of Missouri School of Medicine KENNETH M. HEILMAN, M.D. Department of Neurology, College of Medicine, University of Florida and Veterans Administration Medical Center, Gainesville ADDRESS FOR CORRESPONDENCE Dr. David Roeltgen, Department of Neurology, University of Missouri School of Medicine, Columbia, MO 65212 ABSTRACT Previous models of agraphia have been descriptive and have emphasized the association of agraphia with other disorders such as aphasia and alexia. Such models have frequently led to inconsistent descriptions of specific agraphia types. These inconsistencies have made clinical-anatomical correlations diffi- cult. Recent studies of agraphic patients with focal cerebral lesions have made it possible to develop a new model of writing based on specific neuropsychological mechanisms. In addition, results from computerized tomography have helped delineate probable anatomic substrates for many of these mechanisms. It is hoped this model provides a means for a better understanding of the mechanisms and anatomy underlying the agraphias as well as a better understanding of the relationships of the agraphias with aphasia and alexia. NEUROLOGICAL METHODS OF WRITING In 1867, Ogle (1867), one of the first to describe and classify disorders of writing, defined agraphia as a writing disorder following a cortical lesion. His discussions of agraphia provide one of the first models of writing. A major focus of his model was the relationship of agraphia and aphasia. Ogle described one patient who was aphasjc but not agraphic and a second who was agraphic but not aphasic. He therefore concluded that although agraphia and aphasia usually occurred together they were occasionally separable. In addition to addressing the relationship of agraphia and aphasia, Ogle classified the agraphias as either amnemonic or atactic. These distinctions demonstrate that as early as 1867, there was delineation of distinct types of agraphia. Later authors also stressed the relationship between agraphia and aphasia. © 1985 Cambridge University Press 0142-7164/85/030205-26 $2.50