1043-3155 Pediatr Neurol Briefs pedneurbriefs Pediatr Neurol Briefs Pediatric Neurology Briefs Pediatr Neurol Briefs 2166-6482 1043-3155 2166-3155 Pediatric Neurology Briefs Publishers Chicago, IL, USA PNB-4-62-a 10.15844/pedneurbriefs-4-8-7 Learning Disorders Neurology Pediatrics Nervous System Diseases Child Development Brain Diseases Neurosurgery Child Infant Alexia, Agraphia, and Frontal Lobe Damage http://orcid.org/0000-0002-0173-7931 Millichap J. Gordon MD 1 2 * Division of Neurology, Children's Memorial Hospital, Chicago, IL Departments of Pediatrics and Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL Correspondence: Dr. J. Gordon Millichap, E-mail: jgmillichap@northwestern.edu 08 1990 01 08 2016 4 8 62 62 Copyright: © 1990 The Author(s) 1990 This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Troubled letters but not numbers. Domain specific cognitive impairments following focal damage in frontal cortex

The case history of a right-handed woman who developed severe and stable alexia and agraphia following a circumscribed surgical lesion in the premotor cortex is reported from the Department of Neurology, Division of Behavioral Neurology and Cognitive Neuroscience, University of Iowa College of Medicine, Iowa City, Iowa.

 Alexia and Agraphia Frontal Lobe Neuroanatomical Basis

The case history of a right-handed woman who developed severe and stable alexia and agraphia following a circumscribed surgical lesion in the premotor cortex is reported from the Department of Neurology, Division of Behavioral Neurology and Cognitive Neuroscience, University of Iowa College of Medicine, Iowa City, Iowa. The lesion was above Broca's area in Exner's area. Her visual perception, intellect, memory, oral spelling, and drawing were normal and she was not aphasic or hemiparetic. She was unable to read sentences and her reading of single words and letters was severely impaired. She could not write recognizable letters or words. By contrast she was able to write numbers and perform written calculations without difficulty. These dissociations of function provide evidence of specificity of cognitive and neural representation. [1]

COMMENT The isolated simultaneous occurrence of alexia and agraphia is rare. In this case the anatomical lesion within the left frontal lobe was unusually circumscribed. The sector of association cortex in the frontal lobe, known as Exner's area, appears to be related to the ability to read and write. The pathology of the small lesion removed surgically was a single metastasis from an adenocarcinoma of the lung. Neurological evaluation was normal except for the cognitive defect described.

The neuroanatomical basis of developmental dyslexia has been debated since this hypothesis was proposed by Orton in 1937. Patterns of task related slow-brain potentials have been investigated in six dyslexic youths by Landwehrmeyer B et al [2]. Whereas control subjects revealed greater left hemisphere negativity during linguistic tasks, the reverse was found with dyslexics. The authors, working at the Neurologische Universitatsklinik, Freiburg, West Germany, concluded that dyslexia is associated with changes in the lateral distribution of cortical activity during certain types of language processing.

 Anderson SW Damasio AR Damasio H Troubled letters but not numbers. Domain specific cognitive impairments following focal damage in frontal cortex Brain 1990 Jun 113 Pt3 749 66 10.1093/brain/113.3.749 2364267 Landwehrmeyer B Gerling J Wallesch CW Patterns of task-related slow brain potentials in dyslexia Arch Neurol 1990 Jul 47 7 791 7 10.1001/archneur.1990.00530070089015 2357160