Classification system for malformations of cortical development

Dr Henry Knipe and A.Prof Frank Gaillard et al.

Classification system for malformations of cortical development organises a myriad of conditions into one of three major underlying groups according to the main underlying mechanism:

  • group I: abnormal cell proliferation or apoptosis
  • group II: abnormal neuronal migration
  • group III: abnormal cortical organisation

As is to be expected a number of conditions fall outside these three groupings and are placed in a miscellaneous group: those associated with other diseases or yet to be classified 2. The classification present below is a summary with examples adapted from the one proposed by Barkovich et al in 1996 and updated in 2001, 2005 and 2012 1-2,5,6. The full classification is extensive, contains numerous rare and specific abnormalities beyond the scope of this or other related articles and will certainly evolve over the coming years. As such, it may be necessary to review the most recent (2012) update 5 for further details. 

Group 1 conditions include those due to disorders of neuronal and/or glial proliferation or apoptosis. They can be further divided into three groups; those with abnormalities of brain size – A) small and B) large – and C) those with cortical dysgenesis with abnormal cells (neoplastic or non-neoplastic) 2.

The cortical dysgenesis with abnormal cell proliferation group contains a number of both neoplastic and non-neoplastic conditions. 

Group III: abnormal post migrational development

  • polymicrogyria and schizencephaly
    • bilateral polymicrogyria syndromes
    • schizencephaly
    • polymicrogyria or schizencephaly as part of multiple congenital anomaly/mental retardation syndromes
  • cortical dysgenesis secondary to inborn errors of metabolism
    • mitochondrial and pyruvate metabolic disorders
    • peroxisomal disorders
  • malformations secondary to inborn errors of metabolism
    • mitochondrial and pyruvate metabolic disorders 
    • peroxisomal disorders 
  • other unclassified malformations
    • sublobar dysplasia 

For other congenital central nervous system classifications see:

  1. classification system for midline abnormalities of the brain
  2. classification system for malformations of the cerebellum
  3. classification system for malformations of the brainstem
Malformations of the central nervous system
Share article

Article information

rID: 15853
Synonyms or Alternate Spellings:
  • Disorders of cortical formation

Support Radiopaedia and see fewer ads

Cases and figures

  • Drag
    Case 1: microcephaly
    Drag here to reorder.
  • Drag
    Tuberous sclerosi...
    Case 2: hamartomas of tuberous sclerosis
    Drag here to reorder.
  • Drag
    Case 3: focal cortical dysplasia with balloon cells
    Drag here to reorder.
  • Drag
    Case 4: gangliocytoma
    Drag here to reorder.
  • Drag
    Case 5: DNET
    Drag here to reorder.
  • Drag
    Case 6: band heterotopia
    Drag here to reorder.
  • Drag
    Case 7: heterotopia - subependymal
    Drag here to reorder.
  • Drag
    Case 8: schizencephaly
    Drag here to reorder.
  • Drag
    Case 9: cortical dysplasia without balloon cells
    Drag here to reorder.
  • Drag
    Case 10: ganglioglioma
    Drag here to reorder.
  • Drag
    Case 11: hemimegalancephaly
    Drag here to reorder.
  • Updating… Please wait.
    Loadinganimation

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.