Hemispheric asymmetries in the orientation and location of the lateral geniculate nucleus in dyslexia.
Dyslexia
; 24(2): 197-203, 2018 May.
Article
en En
| MEDLINE
| ID: mdl-29380470
ABSTRACT
Human brain asymmetry reflects normal specialization of functional roles and may derive from evolutionary, hereditary, developmental, experiential, and pathological factors (Toga & Thompson, 2003). Geschwind and Galaburda (1985) suggested that processing difficulties in dyslexia are due to structural differences between hemispheres. Because of its potential significance to the controversial magnocellular theory of dyslexia, we investigated hemispheric differences in the human lateral geniculate nucleus (LGN), the primary visual relay and control nucleus in the thalamus, in subjects with dyslexia compared to normal readers. We acquired and averaged multiple high-resolution proton density (PD) weighted structural magnetic resonance imaging (MRI) volumes to measure in detail the anatomical boundaries of the LGN in each hemisphere. We observed hemispheric asymmetries in the orientation of the nucleus in subjects with dyslexia that were absent in controls. We also found differences in the location of the LGN between hemispheres in controls but not in subjects with dyslexia. Neither the precise anatomical differences in the LGN nor their functional consequences are known, nor is it clear whether the differences might be causes or effects of dyslexia.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Dislexia
/
Variación Anatómica
/
Cuerpos Geniculados
Tipo de estudio:
Observational_studies
Límite:
Adult
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Female
/
Humans
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Male
Idioma:
En
Revista:
Dyslexia
Asunto de la revista:
NEUROLOGIA
Año:
2018
Tipo del documento:
Article
País de afiliación:
Canadá