Biomaterial Database

Abnormal callosal morphology in male adult dyslexics: relationships to handedness and phonological abilities. 1998

F Robichon, and M Habib

Laboratoire Cognition et Mouvement, C.N.R.S., Marseille, France. Fabrice.Robichon@u-bourgogne.fr

The classical notion that developmental dyslexia may somehow relate to impaired communication between hemispheres has not yet received convincing support. Sixteen dyslexic adults and 12 controls received a high resolution brain MRI scan for morphometric study of the corpus callosum. Automatized measurements of callosal area and calculation of indices defining the general morphology of the callosal mid-surface were performed. Each participant received global intelligence and reading achievement evaluation; dyslexics were further proposed specific neuropsychological tests specially designed to explore the mechanisms of reading impairment. It just appears from the group comparisons (1) that the dyslexics' corpus callosum displays a more circular and evenly thicker general shape, and (2) that the midsagittal surface is on the average larger than in controls, in particular in the isthmus. Moreover, the different morphometric characteristics of the dyslexic brain correlated with the degree of impairment on various tests exploring phonological abilities. In vivo morphometry of the corpus callosum may provide valuable hints for understanding developmental learning disorders and their consequences in adults.

UI	MeSH Term	Description	Entries
D007839	Functional Laterality	Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.	Ambidexterity,Behavioral Laterality,Handedness,Laterality of Motor Control,Mirror Writing,Laterality, Behavioral,Laterality, Functional,Mirror Writings,Motor Control Laterality,Writing, Mirror,Writings, Mirror
D008297	Male		Males
D009483	Neuropsychological Tests	Tests designed to assess neurological function associated with certain behaviors. They are used in diagnosing brain dysfunction or damage and central nervous system disorders or injury.	Aphasia Tests,Cognitive Test,Cognitive Testing,Cognitive Tests,Memory for Designs Test,Neuropsychological Testing,AX-CPT,Behavioral Assessment of Dysexecutive Syndrome,CANTAB,Cambridge Neuropsychological Test Automated Battery,Clock Test,Cognitive Function Scanner,Continuous Performance Task,Controlled Oral Word Association Test,Delis-Kaplan Executive Function System,Developmental Neuropsychological Assessment,Hooper Visual Organization Test,NEPSY,Neuropsychologic Tests,Neuropsychological Test,Paced Auditory Serial Addition Test,Repeatable Battery for the Assessment of Neuropsychological Status,Rey-Osterrieth Complex Figure,Symbol Digit Modalities Test,Test of Everyday Attention,Test, Neuropsychological,Tests, Neuropsychological,Tower of London Test,Neuropsychologic Test,Test, Cognitive,Testing, Cognitive,Testing, Neuropsychological,Tests, Cognitive
D010700	Phonetics	The science or study of speech sounds and their production, transmission, and reception, and their analysis, classification, and transcription. (Random House Unabridged Dictionary, 2d ed)	Speech Sounds,Sound, Speech,Sounds, Speech,Speech Sound
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D004410	Dyslexia	A cognitive disorder characterized by an impaired ability to comprehend written and printed words or phrases despite intact vision. This condition may be developmental or acquired. Developmental dyslexia is marked by reading achievement that falls substantially below that expected given the individual's chronological age, measured intelligence, and age-appropriate education. The disturbance in reading significantly interferes with academic achievement or with activities of daily living that require reading skills. (From DSM-IV)	Alexia,Dyslexia, Developmental,Reading Disability, Developmental,Reading Disorder,Reading Disorder, Developmental,Developmental Reading Disorder,Word Blindness,Alexias,Blindness, Word,Blindnesses, Word,Developmental Dyslexia,Developmental Dyslexias,Developmental Reading Disabilities,Developmental Reading Disability,Developmental Reading Disorders,Disabilities, Developmental Reading,Disability, Developmental Reading,Disorder, Developmental Reading,Disorder, Reading,Disorders, Developmental Reading,Disorders, Reading,Dyslexias,Dyslexias, Developmental,Reading Disabilities, Developmental,Reading Disorders,Reading Disorders, Developmental,Word Blindnesses
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000293	Adolescent	A person 13 to 18 years of age.	Adolescence,Youth,Adolescents,Adolescents, Female,Adolescents, Male,Teenagers,Teens,Adolescent, Female,Adolescent, Male,Female Adolescent,Female Adolescents,Male Adolescent,Male Adolescents,Teen,Teenager,Youths
D061085	Agenesis of Corpus Callosum	Birth defect that results in a partial or complete absence of the CORPUS CALLOSUM. It may be isolated or a part of a syndrome (e.g., AICARDI'S SYNDROME; ACROCALLOSAL SYNDROME; ANDERMANN SYNDROME; and HOLOPROSENCEPHALY). Clinical manifestations include neuromotor skill impairment and INTELLECTUAL DISABILITY of variable severity.	Absence of Corpus Callosum,Corpus Callosum Agenesis,Corpus Callosum Dysgenesis,Corpus Callosum Hypogenesis,Corpus Callosum Malformation,Corpus Callosum, Agenesis Of,Ageneses, Corpus Callosum,Agenesis, Corpus Callosum,Corpus Callosum Absence,Corpus Callosum Absences,Corpus Callosum Ageneses,Corpus Callosum Dysgeneses,Corpus Callosum Hypogeneses,Dysgeneses, Corpus Callosum,Dysgenesis, Corpus Callosum,Hypogeneses, Corpus Callosum,Hypogenesis, Corpus Callosum