Ictal spikes

Figure 16.3 Changes in neuronal function required for the development of epileptic seizures. The factors that may control or induce the changes in neuronal function that turn a normal neuron into a focal one (A) recruit other neurons (focal epileptogenesis) to produce an interictal EEG spike (B) and ensure the spread of activity (general epileptogenesis) to full ictal activity (C) are discussed in the text. They include alterations to various ion channels, especially those for Na, a reduction in local inhibitory activity or an increase in local excitatory drive. The electrophysiological counterparts of some of the events involved are shown in Fig. 16.2...

Besides ictal events, BOLD signal is also measured in human interictal discharges (Benar et al., 2002). It is unknown how this period of relative ictal/interictal ischemia impacts neuronal function or causes permanent damage. However, in humans, interictal spikes may be associated with transient negative impact on cognition (Shewmon and Erwin, 1988 Binnie and Marston, 1992). 

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