Fig. 5.

Cartoon comparing different types of seizure models with the detected focus in patient A. The focus index score and corresponding electrocorticogram for channel 21, patient A, are shown above with separately recorded examples of ictal-like events in animal models. The local field potential recording (LFP) illustrates an ictal-like event in mouse sensorimotor cortex activated with kainate 400 nM, under conditions of transient alkalinization of artificial cerebrospinal fluid (pH 7.4–8.4). The bottom trace is a recording of excitatory events in a cortical pyramidal neuron in the low extracellular magnesium model of cortical seizures [45]. Note in each “field recording” that an electrodecremental period precedes the generation of large-amplitude repetitive bursts at α–θ frequency. The pyramidal neuronal recording suggests that this population event may correspond to synchronous plateau depolarizations in cortical principal cells (see Section 4). Note the time scales of each example are not equal.