M.L. MANESCHI, G. BERSANI - Vol. 9, March 2003, Issue 1
Testo Immagini Bibliografia Summary Indice
Dislessia e Schizofrenia
Dyslexia and Schizophrenia
According to the International Federation of Neurology, Dyslexia is: "A disorder which presents with learning difficulty in reading despite conventional teaching, adequate intelligence and fair socio-cultural opportunities. It is caused by basic cognitive disabilities which often are constitutional in origin" (Critchley, 1975). At times it is associated with alteration of language, especially in the most severe forms of the disorder, with involvement of the various aspects of cognition, particularly attention, memory and perception, which are mainly important for appropriate development of individual-environment relationships.
In the last decades great importance has been attached to changes in learning, writing and/or reading, identifying in adults who had already acquired such skills, the existence of nervous tissue damage. Such changes were seen to be linked with altered neuronal cytoarchitecture, which may refer to various aetiological hypotheses that could rely on genetic and/or environmental factors. Further purely cognitive research determined the frequency of neurodevelopmental changes or neurological lesions linked to cognitive deficit in psychiatric disorders, particularly schizophrenia.
Various theories were considered, like the "right shift gene", a metabolic brain alteration, detective maturation of neocortical circuitry, and the possible cerebellar involvement in cognitive function integrity.
Further neuroimaging and genetic studies, as well as pedigree analysis of patients with cognitive impairment and/or psychiatric disorders, may continue to provide information on the role of one or more factors at the origin of such defects.