Cognitive outcome of early unilateral lesions in children with epilepsy

Date of Award




Degree Name

Doctor of Philosophy (Ph.D.)



First Committee Member

Bonnie Levin - Committee Chair

Second Committee Member

Maria Llabre - Committee Member


Intellectual functioning (IQ) was assessed in 54 children and adolescents with intractable epilepsy who later underwent cortical resection due to unilateral developmental lesions acquired in utero. Lesion type was classified into delimited mass lesions, and mild, moderate, and severe diffuse cortical dysplasia based on histopathological analysis of surgical tissue. Laterality of lesion was determined through neurological examination, electrophysiological and neuroradiological procedures. Classification of lesion type was corroborated by its significant relationship with other disease-related variables known to be related to clinical severity (age of seizure onset, age of resection, and extent of lesion).Analyses of covariance revealed that circumscribed mass lesions had a less deleterious effect on non-verbal IQ than diffuse cortical dysplasia, after controlling for age of seizure onset and extent of lesion. This effect was also found on verbal IQ measures, but only in those subjects with right-sided lesions. Subjects with left-sided lesions performed significantly more poorly on verbal IQ measures than those with right-sided lesions, emphasizing the importance of early left hemisphere development on cognitive functioning. Additionally, younger age of onset and greater extent of lesion were associated with poorer cognitive outcome. This is one of the first studies to date to examine lesion pathology and laterality simultaneously, and to integrate empirically-measured clinical outcome with known abnormal neurodevelopmental processes.


Psychology, Psychobiology; Psychology, Developmental; Psychology, Cognitive

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