title: The histopathology of polymicrogyria: a series of 71 brain autopsy studies.
abstract: OBJECTIVE
  Polymicrogyria (PMG) is one of the most common forms of cortical malformation yet the mechanism of its development remains unknown. This study describes the histopathological aspects of PMG in a large series including a significant proportion of fetal cases.
  
  
  METHODS
  We have reviewed the neuropathology and medical records of 44 fetuses and 27 children and adults in whom the cortical architecture was focally or diffusely replaced by one or more festooning bands of neurons.
  
  
  RESULTS
  The pial surface of the brain overlying the polymicrogyric cortex was abnormal in almost 90% of cases irrespective of the aetiology. This accords with animal studies indicating the importance of the leptomeninges in cortical development. The aetiology of PMG was highly heterogeneous and there was no correlation between cortical layering patterns and aetiology. PMG was almost always associated with other brain malformations.
  
  
  CONCLUSIONS
  The inclusion of many fetal cases has allowed us to examine the early developmental stages of PMG. The study indicates the significance of surface signals responsible for human corticogenesis and the complex interaction between genetic and environmental factors leading to this common endpoint of cortical maldevelopment.
authors.affiliation: Pediatric Neurology Unit, Department of Pediatrics, UZ Brussel, Brussels, Belgium.|Department of Public Health, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Anna C
authors.initials: AC
authors.lastname: Jansen
authors.affiliation: Department of Pathology, Centre Hospitalier Universitaire Sainte-Justine, Université de Montreal, Montreal, QC, Canada.
authors.forename: Yves
authors.initials: Y
authors.lastname: Robitaille
authors.affiliation: Department of Clinical Neuropathology, King's College Hospital, Denmark Hill, London, UK.|Service of Anatomic Pathology, Hospital Pedro Hispano, Matosinhos, Portugal.
authors.forename: Mrinalini
authors.initials: M
authors.lastname: Honavar
authors.affiliation: Department of Clinical Neurophysiology, King's College Hospital, Denmark Hill, London, UK.
authors.forename: Nandini
authors.initials: N
authors.lastname: Mullatti
authors.affiliation: Department of Neurology, University Department of Pediatrics, Murdoch Children's Research Institute, Royal Children's Hospital, The University of Melbourne, Parkville, Vic., Australia.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Leventer
authors.affiliation: Neurogenetics Unit, Montreal Neurological Hospital and Institute, and Departments of Neurology & Neurosurgery and Human Genetics, McGill University, Montreal, QC, Canada.
authors.forename: Eva
authors.initials: E
authors.lastname: Andermann
authors.affiliation: Seizure Clinic, Montreal Neurological Hospital and Institute, and Departments of Neurology & Neurosurgery and Paediatrics, McGill University, Montreal, QC, Canada.
authors.forename: Frederick
authors.initials: F
authors.lastname: Andermann
authors.affiliation: Department of Neuropathology, Oxford University John Radcliffe Hospital, Oxford, UK.
authors.forename: Waney
authors.initials: W
authors.lastname: Squier
mesh_terms: D000293:Adolescent; D000328:Adult; D001344:Autopsy; D001921:Brain / Q000166:cytology / Q000254:growth & development / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005333:Fetus / Q000166:cytology / Q000473:pathology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D065706:Polymicrogyria / Q000473:pathology*; D055815:Young Adult