Relationship between encephalopathy and abnormal neuronal activity in the developing brain.

Abstract

Infantile spasms represent a unique age-specific epileptic syndrome that is often associated with a focal or diffuse encephalopathy and can result in severe neurodevelopmental delay and retardation. The behavioral and electroencephalogram (EEG) phenotype of infantile spasms is similar, despite its association with multiple neurological disease states. The stereotypy suggests that the spasms originate from a highly age-specific hyperexcitable network. Treatment strategies for infantile spasms remain largely empirical due to the lack of understanding of the underlying neurochemistry and circuitry. This chapter reviews experimental evidence for the presence of unique developmental factors that appear to promote hyperexcitability in the immature brain and that may play a role in the generation of infantile spasms. In addition, this chapter evaluates the potential interplay between an associated developmental encephalopathy and enhanced neuronal hyperexcitability in infantile spasms.