Prognostic Factors for Poor Surgical Outcome in Patients with Temporal Lobe Epilepsy.
Abstract number :
3.177
Submission category :
Year :
2001
Submission ID :
2757
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
C.J. Milling, M.D., Neurology, University of Michigan, Ann Arbor, MI; P.M. Vijayakumar, M.D., Neurology, University of Michigan, Ann Arbor, MI; E.A. Passaro, M.D., Neurology, University of Michigan, Ann Arbor, MI; E. Kutluay, M.D., Neurology, University o
RATIONALE: The majority of temporal lobe epilepsy (TLE) patients with clinical and EEG data concordant with either MRI-identified hippocampal atrophy (HA) or fluoro-deoxyglucose (FDG)-PET imaging are seizure free after anterior temporal lobectomy (ATL). However, there are a subset of patients that have recurrent seizures. The purpose of this study is to determine the variables that distinguish patients with a poor surgical outcome.
METHODS: We identified 16 TLE patients with recurrent seizures after [dsquote]skip[dsquote] ATL prior to 1998 (group 1) and compared them to 18 randomly chosen TLE patients (group 2) who were seizure free after [dsquote]skip[dsquote] ATL during the same time period. Patients qualified for a [dsquote]skip[dsquote] ATL when clinical and non-invasive EEG data were concordant with either MRI identified HA or unilateral temporal hypometabolism on FDG-PET (crytpogenic TLE). A number of clinical, EEG and radiological variables were compared between the two groups. Chi-square, Fisher[scquote]s exact test and t-test analyses were used. All statistically significant results were set at p-values [lt]0.05.
RESULTS: Cryptogenic TLE was significantly more frequent in the group with recurrent seizures (Group 1 = 56%), as compared with patients that were seizure free (Group 2 =11% (p [lt]0.009)). There was no significant difference in the presence of bilateral HA between the two groups (Group 1=12% and Group 2=0%). There were no significant differences with regard to the clinical or electrophysiological variables evaluated including age at seizure onset (Group 1 mean =14.7 years, Group 2 mean = 11.1 years), duration of epilepsy (Group 1 mean=19.1 years, Group 2 mean = 19.8 years), presence of an aura (Group 1= 93%, Group 2 = 88%), presence of visceral aura or fear (Group 1 =43%, Group 2 =33%), presence of discordant neuropsychological data (Group 1 = 25%, Group 2 = 11%), presence of bilateral interictal epileptiform (IEDs) discharges (Group 1 = 43%, Group 2 =22%) or absence of IEDs (Group 1= 12%, Group 2=16%).
CONCLUSIONS: TLE patients with recurrent seizures after [dsquote]skip[dsquote] ATL are more likely to have cryptogenic TLE. The clinical and neurophysiological variables evaluated so far do not distinguish patients with recurrent seizures from those who are seizure free ATL.