AMNESIA OF THE EPILEPTIC AURA

In a prospective study lasting 6 months, we recorded on video 108 seiz ures with aura of 23 patients in an attempt to evaluate the mechanisms involved in the encoding of memories. In 88 of those seizures, we als o recorded an EEG. The percentage of auras remembered decreased signif icantly with increasing severity of the seizures. The recollection of auras was also significantly dependent on the ictal EEG changes during the aura. Ninety-seven percent of the auras without EEG changes, 94% of the auras with unilateral EEG changes, and 73% of the auras with bi lateral EEG changes during the aura were remembered. The spread of the ictal EEG pattern during the aura also showed a significant correlati on with the severity of the ensuing seizure. Three patients with bitem poral epilepsy made up a considerable proportion of those who never re membered their aura before secondary generalized tonic-clonic seizures (2 of 3) and of those who had a transient postictal amnesia of their aura (2 of 3). The only patient who failed to remember a previously do cumented isolated aura also suffered from bitemporal epilepsy. During the second part of the study, we questioned whether information provid ed during the history could be helpful in defining the type of epileps y syndrome or localizing the EEG seizure pattern of the 80 patients wh o had been admitted for presurgical epilepsy diagnosis. Localized (reg ional, unilateral, and independent left and right lateral) EEG seizure patterns occurred in 82% of the 51 patients with auras in their histo ry as compared with 24% of the 17 patients who did not have auras in t heir history (p < 0.01).