Learning objectives
1) To review the recent classification of malformations of cortical development. 2) To describe and illustrate the MR imaging findings of malformations of cortical development on 1.5 T and 3 T.
Background
Cortical malformations are being increasingly recognized as a significant cause of developmental delay, focal neurological deficit, refractory epilepsy and mental retardation. Many of these malformations present in the neonatal period or infancy. Proper diagnosis and rational classification of these disorders is essential for prognosis, genetic testing and counseling, and investigation of the underlying olecular causes.Table 1.: Stage of brain development correlates with the brain malformation pathology. Stage of brain development Time Pathology Dorsal induction 3-7w Neural tube defects Ventral induction 5-w Holoprosencephaly NeuronaMil glial proliferation...
Imaging findings OR Procedure details
1. Malformations due to abnormal neuronal and glial proliferation or apoptosis. A. Decreased Proliferation/Increased Apoptosis: Microcephalies What is it: Reduced proliferation of neurons and glia in the germinal zones The circumference of the head is at least 3 standard deviations below the mean Best imaging clue: Few gyri and abnormally shallow sulci (50% of normal depth) may be present B. Increased Proliferation/Decreased Apoptosis (normal cell types): Megalencephalies What is it: Increased proliferation of neurons and glia in the germinal zones The circumference of the head...
Conclusions
Current MR imaging techniques can clearly demonstrate the morphology, distribution and extent of malformations of cortical development. The understanding of the classification and the MR imaging findings is essential for proper diagnosis, prognosis, therapy and genetic counseling.
Personal Information
Jans Lennart, MD. Department of radiology and magnetic resonance imaging. Ghent University Hospital, De Pintelaan 185, 9000 Gent, Belgium.
[email protected] Deblaere Karel, MD PHd. Department of radiology and magnetic resonance imaging. Ghent University Hospital, De Pintelaan 185, 9000 Gent, Belgium. Dekeyser Sofie, MD. Department of radiology and magnetic resonance imaging. Ghent University Hospital, De Pintelaan 185, 9000 Gent, Belgium. De Groote Thomas, MD. Department of radiology and magnetic resonance imaging. Ghent University Hospital, De Pintelaan 185, 9000 Gent, Belgium. Meersschaut Valerie, MD. Department of pediatric...
References
Barkovich AJ, Kuzniecky RI, Jackson GD, Guerrini R, Dobyns WB. Classification for malformations of cortical development: Update 2001. Neurology 2001; 57; 2168-2178. Palmini A. et al. Terminology and classification of the cortical dysplasias. Neurology 2004; 62: S2- S8. Leventer RJ, Phelaln EM, Coleman LT, Kean MJ, Jackson GD, Harvey AS. Clinical and imaging features of cortical malformation in childhood. Neurology 1999 53(4): 715-22. Sanjay MS. Malformations of cortical development: burdens and insights from important causes of human epilepsy. Lancet neurology 2004 (3), 29-38. Deblaere K,...