[Clinical picture of neuroblast migratory disorders]

Disturbances of neuroblast migration are prominent among the numerous causes of symptomatic epilepsy and of abnormal neurological development in children.

Although their clinical manifestations are generally nonspecific with considerable overlap of symptoms and signs amongst the various disorders, the clinical picture of migratory disorders is continuously being redefined with greater precision and, in some cases, disorders of migration may be grouped into syndromes that are more easily diagnosed during life, in large part because of major advances in recent years in the technology of neuroimaging and in molecular genetics. It is therefore possible to study these patients in greater detail and over longer periods when detected early in life.

I have reviewed the clinical manifestations of some of the defined disorders of neuroblast migration: lissencephaly-pachygyria types I and II, pachygyria, schizencephaly, polymicrogyria, special location heterotopia, for example, periventricular heterotopia and subcortical band heterotopia or 'double cortex' syndrome, the latter closely related to isolated lissencephaly type I.