Neurotrophic Factors in the Pathogenesis of Neurological Disorders with Mental Retardation in Children

Neurotrophic factors are important for neuronal growth, differentiation, survival of neurons and synaptic formation of certain brain cells. Neurotrophic factors from cerebrospinal fluid (CSF) in neurological disorders both acute and rapidly progressive chronic neurological disorders that lead to mental retardation were studied. Their role in the pathogenesis of neurological disorders was assessed to see whether they may serve as prognostic markers. In neonates suffering from severe asphyxia, increased brain-derived nerve growth factor (BDNF) might counteract neuronal damage. The level of beta-neurotrophic factor (NGF) might serve as a marker of asphyxia. Children with cryptogenic infantile spasms had largely normal levels of NGF, but children with symptomatic spasms had low to negligible levels. The therapeutic action of adrenocorticotrophic hormone may be mediated by a potentiation of neural growth factors. Patients with Rett syndrome had low concentrations of CSF NGF compared with controls and autistic patients. NGF might be important for the function of cholinergic neurons in Rett syndrome. Low levels of CSF insulin-like growth factor-1 were found in patients with progressive encephalopathy-hypsarrhythmia-optic atrophy syndrome with cerebellar atrophy and in white matter diseases and infantile ceroid lipofuscinosis. Neurotrophic factors may be involved in the pathogenesis of some neurodegenerative diseases. Whether neurotrophic therapies prevent or arrest progression of these diseases still awaits confirmation in clinical trials.