Epileptic seizures are episodic, transient events with clinical manifestations that reflect the regions of seizure onset and subsequent involvement (i.e., propagation with or without secondary generalization). One recent study with intracranial recordings (Afra et al., 2008) found that complex partial seizures of mesial temporal onset had an average duration of only 106 seconds, and those with extratemporal neocortical onset lasted an average of only 78 seconds. This brief duration and the rapidly changing dynamics of the discharge pose various challenges for seizure detection. Even patients with very refractory and frequent seizures spend the vast majority of time in nonseizure (interictal) states. For example, a patient with very refractory complex partial seizures originating from mesial temporal regions who had 20 seizures per month (average duration, 2 minutes) would only be in the ictal state 0.1% of the time, and the other 99.9% would be spent in interictal (and postictal) states. Despite this brief total seizure time, the disruptive and recurrent nature of complex partial seizures (even without secondary generalization) has a major impact on the quality of life of patients with refractory epilepsy. When discussing seizure detection, it is useful to differentiate between early seizure detection, the topic of this chapter, and seizure detection that is not time sensitive.
|Original language||English (US)|
|Title of host publication||Epilepsy|
|Subtitle of host publication||Mechanisms, Models, and Translational Perspectives|
|Number of pages||16|
|State||Published - Jan 1 2010|
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