[Congenital brain malformations]

Malformations of the central nervous system belong to the most common developmental disorders in humans. The clinical presentation of brain malformations is nonspecific including developmental delay, hypotonia, and/or epilepsy. The great heterogeneity concerning etiology, mechanisms of development and morphology is challenging for diagnosis and classification of brain malformations. Thereby recognizing specific malformations is essential for optimal patient management and prognostic evaluation. The aim of this article is to give an overview of several clinically relevant brain malformations occurring from different disrupted developmental processes in brain formation.

Several brain malformations are already diagnosed during routine ultrasound in pregnancy. However pre- and postnatal magnetic resonance imaging remains the gold standard in detecting the partially subtle changes and to classify the malformations.

Advances in pre- and postnatal neuroimaging techniques and increasing investigation of genetic mechanisms underlying brain formation and its abnormalities have led to a better understanding of embryologic development and pathogeneses of brain malformations.

Besides patient's history and clinical phenotype, neuroimaging plays a key role in diagnosis. Not always a specific diagnosis can be made, but neuroimaging patterns often enable a focused genetic testing and therefore are revolutionary for etiologic and prognostic assignment. Basic knowledge of brain development facilitates understanding and classifying of structural brain abnormalities.