ABSTRACT
Epilepsy is the single most common serious brain disorder in every country of the world and is also one of the most universal of all medical disorders, affecting all ages, races, social classes, and nations (Janca et al. 1997). Among the 40 epileptic clinical syndromes, temporal lobe epilepsy (TLE) is the most common chronic partial epilepsy, affecting nearly 50 million people worldwide. TLE is a heterogeneous disorder and is thought to develop via a cascade of dynamic biological events that alter the balance between excitation and inhibition in limbic neural networks. Although it is not yet clear which mechanisms are necessary or suf–cient for the development of epilepsy, a number of recent studies have provided evidence for circadian rhythmicity in the occurrence of seizures, both in humans and in animal models of chronic epilepsy (Arida et al. 1999; Quigg et al. 1998, 2000; Herman et al. 2001; Hofstra and de Weerd 2009; Hofstra et al. 2009). Several factors are thought to contribute to the pattern of seizure recurrence, such as state-dependent changes in neuronal excitability associated with the sleep-wake cycle, daily rhythms of hormone release, and body temperature (Quigg et al. 1998, 2001; Herman et al. 2001).
