Despite major advances in our understanding of its neurobiology, sleep remains an enigma. Its true function and even the amount needed for optimum brain performance remain uncertain (Frank 2006). However, the need to sleep is imperative, reflecting the fact that sleepiness, like hunger and thirst, is a true drive state. Sleepiness can only be satiated by sleep itself. Moreover, severely disordered sleep can profoundly affect cognition, mental health, and physical well-being.Although sleep medicine has a traditionally low profile in neurology teaching and practice, sleep-related phenomena are frequently associated with numerous neurological disorders. Conversely, sleep problems can adversely affect familiar conditions such as headache and epilepsy. Furthermore, in large surveys, sleep-related symptoms are undoubtedly common with 25 per cent of the population reporting problems that significantly and regularly impact on daily activities.