NEURONAL MIGRATION DISORDERS AND EPILEPSY - A MORPHOLOGICAL ANALYSIS OF 3 SURGICALLY TREATED PATIENTS

Despite the increasing number of patients affected by neuronal migrati on disorders (NMDs) recently diagnosed in vivo by means of magnetic re sonance imaging (MRI), few detailed data on the correlation between th e neuroradiological and the anatomical features in the single NMD case are available, The present paper reports a combined cytoarchitectural and immunocytochemical analysis, by means of antisera recognizing spe cific neuronal and glial markers, of three MRI diagnosed NMD patients surgically treated for the relief of intractable seizures, The first c ase was a giant subcortical nodular heterotopia of morphologically nor mal neurons lacking any type of cortical lamination, The second case w as a layered polymicrogyria with an abnormal amount of ectopic neurons in the underlying white matter. The third case was a focal cortical d ysplasia characterized by a dramatic disruption of the normal cortical layering associated with marked cytological abnormalities, The presen t data demonstrate that the macroscopical and microscopical brain abno rmalities can be markedly different in different NMD subtypes, and sug gest that different anatomical substrates can underlie the intrinsic h yperexcitability of these brain malformations. The relevance of furthe r prospective clinico-morphological studies for a better understanding of the mechanisms determining the development of these brain malforma tions is underlined.