Ordinary and extraordinary brain development: Anatomical variation in developmental dyslexia.
1Beth Israel Hospital, Harvard Medical School, Boston, Massachusetts.
Annals of Dyslexia
|November 16, 2013
Summary
Developmental dyslexia is linked to absent brain asymmetry in language areas and cortical abnormalities. Animal models suggest reduced neural pruning and early focal injury may cause these changes.
Area of Science:
- Neuroscience
- Developmental Neuroscience
- Neuropathology
Background:
- Developmental dyslexia is a common neurodevelopmental disorder affecting reading ability.
- Previous research suggests potential structural brain differences in individuals with dyslexia.
Purpose of the Study:
- To investigate neuropathological findings in the brains of individuals with developmental dyslexia.
- To explore potential causes for observed brain abnormalities.
Main Methods:
- Post-mortem analysis of eight brains (six male, two female) diagnosed with developmental dyslexia.
- Examination of cerebral cortex, specifically the planum temporale and perisylvian regions.
- Histological assessment for cortical malformations and scarring.
Main Results:
- Absence of typical planum temporale asymmetry in all analyzed dyslexic brains.
- Multiple focal cortical malformations and scarring observed in language-relevant brain regions, particularly in males.
- Scarring dated to early life, often in vascular watershed territories.
Conclusions:
- Developmental dyslexia is associated with atypical brain structure, including absent asymmetry and cortical anomalies.
- Findings suggest that reduced neural pruning and early focal injury, potentially immune-related, may contribute to dyslexia.
- Further research in animal models supports the link between immune disorders, cortical injury, and dyslexic brain characteristics.
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