Spike-and-wave is the term that describes a particular pattern of the electroencephalogram (EEG) typically observed during epileptic seizures. A spike-and-wave discharge is a regular, symmetrical, generalized EEG pattern seen particularly during absence epilepsy, also known as ‘petit mal’ epilepsy. The basic mechanisms underlying these patterns are complex and involve part of the cerebral cortex, the thalamocortical network, and intrinsic neuronal mechanisms. The first spike-and-wave pattern was recorded in the early twentieth century by Hans Berger. Many aspects of the pattern are still being researched and discovered, and still many aspects are uncertain. The spike-and-wave pattern is most commonly researched in absence epilepsy, but is common in several epilepsies such as Lennox-Gastaut syndrome (LGS) and Ohtahara syndrome. Anti-epileptic drugs (AEDs) are commonly prescribed to treat epileptic seizures, and new ones are being discovered with less adverse effects. Today, most of the research is focused on the origin of the generalized bilateral spike-and-wave discharge. One proposal suggests that a thalamocortical (TC) loop is involved in the initiation spike-and-wave oscillations. Although there are several theories, the use of animal models has provided new insight on spike-and-wave discharge in humans.