title: Dysembryoplastic neuroepithelial tumors: a model for examining the effects of pathology versus seizures on cognitive dysfunction in epilepsy.
abstract: OBJECTIVE
  Dysembryoplastic neuroepithelial tumors (DNTs) provide a unique model for studying the effects of seizures on cognitive development. Epilepsy and antiepileptic medications are prominent features in the lives and schooling of people who develop seizures in childhood. People with an adult onset share the same underlying brain pathology, but their childhood development is unaffected by seizures. Therefore, DNTs provide a model to examine the specific influence of seizures and their treatment on cognitive development, over and above the effects of the underlying pathology in epilepsy.
  
  
  METHODS
  We examined the neuropsychological characteristics of 56 adults with DNT and medically intractable epilepsy (mean age 32.7 years). Twenty-two adults (39%) had an age of onset of epilepsy before the age of 12 years (childhood-onset group). Scores on tests of intelligence (Verbal IQ and Performance IQ), reading, working memory, verbal learning, verbal recall, visual learning, and expressive and receptive language ability were analyzed.
  
  
  RESULTS
  There were no significant localization effects (right vs. left vs. extratemporal) on any of the neuropsychological test scores. In the group as a whole, the neuropsychological test scores were significantly lower than healthy, age-matched controls on measures of Verbal IQ (p < 0.01), naming p < 0.01, verbal learning (p < 0.01), and working memory (p < 0.05). The childhood-onset group had significantly lower scores on the measures of Verbal IQ (p < 0.01), Performance IQ (p < 0.05), reading (p < 0.05), naming (p = 0.05), and verbal retention (p < 0.05) than those with an onset of seizures at the age of 12 or older.
  
  
  CONCLUSIONS
  The traditional pattern of lateralized memory deficits seen in people with hippocampal sclerosis may not be present in people with temporal lobe epilepsy associated with a DNT. The presence of seizures and their treatment in early childhood may adversely influence the development of these core cognitive abilities, resulting in patterns of cognitive deficits that remain apparent in adulthood.
authors.affiliation: Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, NIHR University College London Hospitals Biomedical Research Centre, London, United Kingdom.
authors.forename: Sallie
authors.initials: S
authors.lastname: Baxendale
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Donnachie
authors.forename: Pamela
authors.initials: P
authors.lastname: Thompson
authors.forename: Josemir W
authors.initials: JW
authors.lastname: Sander
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000150:complications* / Q000503:physiopathology; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000209:etiology* / Q000503:physiopathology; D004827:Epilepsy / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D018302:Neoplasms, Neuroepithelial / Q000150:complications* / Q000503:physiopathology; D009483:Neuropsychological Tests; D012640:Seizures / Q000209:etiology* / Q000503:physiopathology
keywords: Cognitive function; Dysembryoplastic neuroepithelial tumor; IQ; Memory; Seizures