Early ontogenic disturbances in cell migration in mentally disabled adult.

Disturbances in cell migration are heterogenic disorders of brain development commonly associated with epilepsy and mental retardation. We report a 45-year-old oligophrenic man with defect of lower limbs and family history of mental retardation who died because of brainstem hemorrhage. At post-mortem and histopathological examination, complex brain malformation characterized by bilateral periventricular heterotopia, cortical dysgenesia, partial agenesia of corpus callosum and thin-walled blood vessels was found. Immunohistochemical examination revealed the presence of fibronectin, collagen IV and laminin in wall of pathological vessels. Cyclooxygenase-2 (COX-2) expression in neurons within heterotopias and dysgenic cortex was negative. It may indicate their maturity and indirectly, normal activity of postsynaptic NMDA receptors that explains absence of epileptic attacks in our patient. The presence of COX-2-negative neurons and compounds of basal lamina in fetal-like vessels within heterotopias and dysgenic cortex, suggests that these probably initially immature structures became mature during 45 years of patient's life.