title: Polymicrogyria-associated epilepsy: a multicenter phenotypic study from the Epilepsy Phenome/Genome Project.
abstract: OBJECTIVE
  Polymicrogyria (PMG) is an epileptogenic malformation of cortical development. We describe the clinical epilepsy and imaging features of a large cohort with PMG-related epilepsy.
  
  
  METHODS
  Participants were recruited through the Epilepsy Phenome/Genome Project, a multicenter collaborative effort to collect detailed phenotypic data on individuals with epilepsy. We reviewed phenotypic data from participants with epilepsy and PMG.
  
  
  RESULTS
  We identified 87 participants, 43 female and 44 male, with PMG and epilepsy. Median age of seizure onset was 3 years (range <1 month to 37 years). Most presented with focal epilepsy (87.4%), some in combination with seizures generalized from onset (23.0%). Focal seizures with dyscognitive features were most common (54.3%). Of those presenting with generalized seizure types, infantile spasms were most prevalent (45.2%). The most common topographic pattern was perisylvian PMG (77.0%), of which the majority was bilateral (56.7%). Generalized PMG presented with an earlier age of seizure onset (median age of 8 months) and an increased prevalence of developmental delay prior to seizure onset (57.1%). Of the unilateral, and asymmetric bilateral groups where PMG was more involved in one hemisphere, the majority (71.4%) of participants had seizures that lateralized to the same hemisphere as the PMG or the hemisphere with greater involvement.
  
  
  CONCLUSIONS
  Participants with PMG had both focal and generalized onset of seizures. Our data confirm the involvement of known topographic patterns of PMG and suggest that more extensive distributions of PMG present with an earlier age of seizure onset and increased prevalence of developmental delay prior to seizure onset.
authors.affiliation: Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Catherine
authors.initials: C
authors.lastname: Shain
authors.forename: Sriram
authors.initials: S
authors.lastname: Ramgopal
authors.forename: Zianka
authors.initials: Z
authors.lastname: Fallil
authors.forename: Isha
authors.initials: I
authors.lastname: Parulkar
authors.forename: Richard
authors.initials: R
authors.lastname: Alongi
authors.forename: Robert
authors.initials: R
authors.lastname: Knowlton
authors.forename: Annapurna
authors.initials: A
authors.lastname: Poduri
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002540:Cerebral Cortex / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004569:Electroencephalography; D004827:Epilepsy / Q000150:complications* / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D054220:Malformations of Cortical Development / Q000150:complications* / Q000175:diagnosis / Q000235:genetics*; D008875:Middle Aged; D010641:Phenotype; D012189:Retrospective Studies; D055815:Young Adult
keywords: Epilepsy; Epilepsy Phenome/Genome Project; Perisylvian; Polymicrogyria