Seizure anticipation: are neurophenomenological approaches able to detect preictal symptoms?

Analysis of electroencephalographic signals and several brain imaging studies suggest that a preictal state precedes the onset of seizures. In this study, we used phenomenological strategies to detect modifications in patients' experience before their seizures. We observed that patients with partial epilepsy feeling an aura (n=9) frequently experienced prodromes (n=6). Prodromes were subtle preictal symptoms, varying among patients and having common negative features. They were generally continuous before seizures and could last hours, whereas auras were sudden and intermittent. All patients were able to recognize facilitating factors. We also found that patients spontaneously develop cognitive countermeasures to avoid facilitating factors (n=6), to prevent a seizure (n=1) or to interrupt a seizure (n=5). Prodromes are not specific enough for clinical use, but could refine the behavioral strategies used in the treatment of epilepsy and the pathophysiology of the preictal state.