%0 Journal Article %T Influence of Sleep and Sleep Deprivation on Ictal and Interictal Epileptiform Activity %A Antonio D¨ªaz-Negrillo %J Epilepsy Research and Treatment %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/492524 %X Sleep is probably one of the most important physiological factors implicated both in epileptic seizures and interictal epileptiform discharges. The neurophysiology concerning the relationship between sleep and epilepsy is well described in the literature; however, the pathological events that culminate in the seizures are poorly explored. The present paper intends to make a rigorous approach to the main mechanisms involved in this reciprocal relation. Knowledge of sleep and sleep deprivation effects in epilepsy stands as crucial in the understanding of how seizures are produced, their possible lines of treatment, and future research. 1. Introduction There is a very important interaction between epilepsy and sleep. This connection is not new; since antiquity, it has been recognized that some seizures only appear during sleep, as a result of which they acquired magical significance. Hippocrates stated that a person affected with epilepsy should ¡°spend the day awake and the night asleep. If this habit be disturbed, it is not so good ¡­ worse of all when he sleeps neither night nor day¡± [1]. Sleep and sleep deprivation have an influence in the onset, frequency, and semiology of seizures, as well as in EEG findings. Some seizure types have different circadian distributions, and understanding these patterns may provide useful diagnostic clues [2]. In 1885, Gowers observed in 850 institutionalized patients that 21% of seizures occurred exclusively at night, 42% only during day, and 37% interchangeably during day or night. In those terms, he classified seizures occurrence as diurnal, nocturnal and diffuse [3]. In 1890 F¨¦r¨¦ studied the times when the seizures occurred over 3 months in epileptic hospitalized patients, finding that two thirds all of seizures occurred between 8£¿p.m. and 8£¿p.m. [4]. Some years later, Langdon-Down and Russell Brain in 1929 analysed 2524 seizures in 66 patients over 6 months: 24% of seizures were nocturnal, 43% daily and 33% occurred randomly [5]. Janz was the first to describe what he called ¡°awakening epilepsy.¡± In 1969, he published five articles about the chronobiology of tonic-clonic generalized seizures in 2825 patients: 44% had seizures during sleep and 33% during waking [6]. Gibberd and Bateson studied 645 patients with epilepsy, founding that sleep-related epilepsy has an ultradian pattern differentiated at the beginning and end of sleep, while seizures in epilepsy daytime waking occur preferentially in the midafternoon [7]. The interaction between sleep and epilepsy is reciprocal; sleep affects the presentation mode of %U http://www.hindawi.com/journals/ert/2013/492524/