Ontwikkeling en ontwikkelingsstoornissen van het humane brein. III. Neuronale migratiestoornissen van de grote hersenen

Neuronal migration disorders of the cerebral cortex form a heterogeneous group of abnormalities, characterised by mental retardation, epilepsy and hypotonia. - They are prevalent in 1% of the population and in 20-40% of the untreatable forms of epilepsy. - Disorders at the start of the migration result in nodular heterotopias. Bilateral periventricular nodular heterotopias are X-linked disorders, in which cortical neurons are unable to leave their position at the ventricular surface due to the absence of filamin I. - The large group of lissencephalies can be divided into a number of syndromes, each of which is characterised by a gene mutation (LISI, DCX, RELN). These mutations result in agyria and pachygyria, which are characteristic for this group. - A number of these abnormalities, especially the smaller nodular heterotopias and focal cortical dysplasia, may be treated by neurosurgical excision.