THE ANATOMY OF EPILEPTIC AURAS - FOCAL PATHOLOGY AND SURGICAL OUTCOME

An aura is generally understood to be the beginning of a seizure. Yet, following successful surgery for intractable epilepsy, patients may have persistent auras even though they are otherwise seizure free. Ninety patients with intractable seizures and auras underwent resective surgery. Forty-three patients had hippocampal sclerosis and 47 had temporal or extratemporal lesions such as glial tumors or vascular malformations. The semiology of the auras was found to have value in localization but not lateralization of the pathology. Epigastric auras as well as gustatory and olfactory auras were significantly more frequent in patients with hippocampal sclerosis than in those with temporal or extratemporal lesions. Auras of vertigo or dizziness were most frequent in patients with extratemporal pathology. There was a significant difference between the pathology groups in the efficacy of resection in eliminating the auras. Of the patients with hippocampal sclerosis who were rendered seizure free, 18.9% had persistent auras, whereas only one (2.6%) of the patients with temporal or extratemporal lesions who were rendered seizure free had persistent auras. These findings suggest that for patients with hippocampal sclerosis an anatomical dissociation between seizure and aura may occur, whereas this dissociation is not present in patients with lesions. Patients suspected of having hippocampal sclerosis should be counseled preoperatively as to the significant likelihood of persistent auras even if seizures are successfully abolished.