Nerve growth factor and brain-derived neurotrophic factor in human paediatric hemimegalencephaly.

Paediatric hemimegalencephaly (HME) is a congenital central nervous system (CNS) disorder, characterized by monolateral cerebral hemisphere enlargement, intractable seizures starting in the post-neonatal period, and mental retardation associated with neuropathological anomalies (mainly cortical thickness and lack of lamination). Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are two neurotrophic factors produced in the mammalian CNS that are involved in the survival, development, and function of a variety of brain cells. In the present study, we found increased cerebral tissue levels of NGF and BDNF in 4 infants with HME; these changes appear to be also associated with abnormal NGF-receptor expression in subcortical blood vessels. Moreover, the marked reduction of cortical choline acetyltransferase immunoreactivity is strongly suggestive of a dysregulation in the NGF differentiative activity in this site that could lead to the pathogenesis of HME.