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Relationship between language lateralization and handedness in left-hemispheric partial epilepsy
C Sveller1, R S Briellmann, M M Saling
1Brain Research Institute, Neurosciences Bldg., Austin Health, Heidelberg West, Victoria, 3081, Australia.
Neurology
|November 30, 2006
Summary
Epilepsy patients with left-sided seizures show altered language lateralization and increased left-handedness. These factors correlate in patients, suggesting the seizure focus impacts brain specialization.
Area of Science:
- Neuroscience
- Neurology
- Cognitive Science
Background:
- Understanding the relationship between handedness and language lateralization is crucial for neurological research.
- Epilepsy, particularly with a left-sided seizure focus, may influence brain organization and hemispheric specialization.
Purpose of the Study:
- To investigate the correlation between language lateralization and handedness in epilepsy patients with left-sided seizure foci.
- To compare these relationships with those in healthy control subjects.
Main Methods:
- Recruited 74 epilepsy patients (left-sided seizure focus) and 70 healthy controls.
- Utilized functional MRI with a noun-verb generation task to determine the language laterality index (LI).
- Assessed handedness using the Edinburgh Handedness Inventory.
Main Results:
- Epilepsy patients exhibited a significant shift towards atypical language lateralization and increased left-handedness compared to controls.
- A significant correlation was found between language laterality index and handedness in epilepsy patients (r = 0.54, p < 0.001), but not in controls.
- The combination of left-handedness and atypical language lateralization was more prevalent in patients (12%) than controls (0%, p < 0.05).
Conclusions:
- Language lateralization is significantly correlated with handedness in epilepsy patients with left-sided seizure foci.
- The observed increase in left-handedness and atypical language lateralization in these patients is likely a consequence of the left-hemispheric seizure focus.
- The seizure focus appears to influence the hemispheric specialization for both language and motor domains.
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