Angels and demons: neurotrophic factors and epilepsy.

Several lines of evidence indicate that neurotrophic factors (NTFs) could be key causal mediators in the development of acquired epileptic syndromes. Yet the trophic properties of NTFs indicate that they might be used to treat epilepsy-associated damage. Accordingly, different NTFs, or even the same NTF, could produce functionally contrasting effects in the context of epilepsy. Recent experimental evidence begins to shed light on the mechanisms underlying these contrasting effects. Understanding these mechanisms will be instrumental for the development of effective therapies, which must be based on a careful consideration of the biological properties of NTFs. Here, we critically evaluate new information emerging in this area and discuss its implications for clinical treatment.