Functional and Anatomic Correlates of Two Frequently Observed Temporal Lobe Seizure-Onset Patterns

[摘要] Intracranial depth electrode EEG recordsof 478 seizures, recorded in 68 patientsundergoing diagnostic monitoring with depthelectrodes, were evaluated to investigate thecorrelates of electrographic onset patterns inpatients with temporal lobe seizures. Theseizure onsets in 78% of these patients wereidentified as either hypersynchronous onsets,beginning with low-frequency, high-amplitudespikes, or low-voltage fast (LVF) onsets,increasing in amplitude as the seizureprogressed. The number of patients (35)having hypersynchronous seizure onsets wasnearly twice that of patients (18) having LVFonsets. Three major differences were seenamong patients with the two seizure-onsetpatterns. When compared with patientshaving LVF onsets, patients with hypersynchronousseizure onsets had a significantlygreater probability of having (1) focal ratherthan regional seizure onsets (p<0.01), (2) seizuresspreading more slowly to the contralateralmesial temporal lobe (p<0.003), and (3) cellcounts in resected hippocampal tissue showinggreater neuronal loss (p<0.001). The resultsprovide evidence that the most frequent electrographic abnormality associated withmesial temporal seizures is local hypersynchrony,a condition associated with majorneuronal-loss in the hippocampus. The resultsalso indicate that LVF seizure onsets morefrequently represent widely distributed discharges,which interact with and spread morerapidly to surrounding neocortical areas.

[学科分类] 精神健康和精神病学