ISOLATED AURA, BUT NOT SUBCLINICAL SEIZURES DURING NON-INVASIVE VIDEO-EEG MONITORING PREDICTS SURGICAL OUTCOME IN MESIAL TEMPORAL LOBE EPILEPSY RELATED TO HIPPOCAMPAL SCLEROSIS
Abstract number :
1.406
Submission category :
Year :
2003
Submission ID :
3829
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
Marino M. Bianchin, Tonicarlo R. Velasco, Veriano Alexandre, Jr., Roger Walz, Charles L. Dalmagro, Luciana M. Inuzuka, Vera C. Terra-Bustamante, Ricardo Guarnieri, Lauro Wichert-Ana, Antonio C. Santos, David Ara[uacute]jo, Dr[aacute]ulio B. de Ara[uacute]
During non-invasive video-EEG (VEEG) for presurgical evaluation of mesial temporal lobe epilepsy associated to hippocampal sclerosis (MTLE-HS), some patients present subclinical seizures or isolated aura. These findings may occur due to more localized epileptic phenomena, suggesting a better surgical outcome. In order to evaluate this aspect, we carried out the present study.
We reviewed clinical, imaging, VEEG, surgical, and anathomopathological records of 234 consecutive patients with MTLE-HS submitted to anterior and mesial temporal lobectomy during 1995 to 2001. Pre-surgical parameters analyzed included: sex, ethnicity, age at surgery, age of epilepsy onset, the duration of epilepsy, positive history for initial precipitating insult, epilepsy duration until surgery, positive family history of seizures in the first-degree offspring, monthly complex partial seizure frequency impairing awareness in the year before surgery, distribution of interictal spikes, neuroimaging, and side of surgery. VEEG data were reviewed, especially regarding the presence of clinical auras and subclinical seizures during the period of the exam. The magnitude of association between the pre-surgical parameters and seizure outcome was measured by odds ratio (OR) and respective 95% confidence interval (CI). Crude and adjusted ORs were estimated by unconditional logistic regression. Statistical significance was determined by Chi-square.
Overall, 82% of the patients became seizure free after anterior and mesial temporal lobectomy. We did not observe differences between patients seizure-free (Engel Class I) and those who remain with seizure among all the studied variables except for isolated auras during the VEEG. Ninety six percent of the patients that presented isolated auras during video-EEG became seizure free when compared with 78% of the patients that had no auras. The chance of seizure free in the group of the patients that presented isolated auras during video-EEG increased about 8 times (CI 95% 1.84 to 33.87, p[lt]0.001). The observed association remain significant after the adjustment by multiple logistic regression.
The presence of isolated aura, but not subclinical seizures predicted a good surgical outcome. Our observation suggests that selected clinical or electrographical parameters easily observed during VEEG monitoring might be predictive of surgical outcome.
[Supported by: FAPESP 02/03743-0, and FAEPA-HC.]