NORMAL BRAIN MRI AND TEMPORAL LOBECTOMY: OUTCOME AND CONCORDANCE IN PREOPERATIVE ASSESSMENT
Abstract number :
1.423
Submission category :
Year :
2003
Submission ID :
3925
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
William O. Tatum IV, Selim R. Benbadis, Leanne S. Heriaud, Fernando L. Vale Department of Neurology, Tampa General Hospital, Tampa, FL; Department of Neurology, University of South Florida, Tampa, FL; Neurosurgery, University of South Florida, Tampa, FL
During the presurgical evaluation for refractory localization-related epilepsy, high-resolution brain MRI plays a routine but central role. A nonlocalizing preoperative MRI often portends a poorer outcome for patients undergoing epilepsy surgery. We assessed preoperative concordance for predictive value in patients undergoing temporal lobectomy with normal high-resolution brain MRI.
Nine patients with normal high-resolution brain MRI underwent temporal lobectomy (TL) for refractory epilepsy at our center by a single epilepsy surgeon. All had anatomic imaging obtained on a GE 1.5 T scanner using a dedicated epilepsy protocol that included T1 standard sagittal images, T2 and FLAIR standard axial images of the whole brain, with 1.5 mm slice thickness for 3-D SPGR coronals, FLAIR (4 skip 1.5), and inversion recovery T2 (4 skip 0) true coronal images. The presence of febrile seizures and seizure characteristics (psychic aura), unilateral interictal IEDs, localized ictal EEG with rhythmic theta discharges at onset, functional imaging with PET/ictal SPECT, and asymmetric IAP results were analyzed for concordance in those seizure-free (SF) and not seizure-free (NSF).
Five of 9 patients became SF after TL with a mean follow-up of 1 year. Five required intracranial EEG though only 1 was SF (2 had 2 surgical procedures). Concordance was seen with unilateral temporal IEDs in 5/5 SF and 2/4 NSF, with ictal rhythmic theta discharges at onset in 3/5 SF and 0/4 NSF, with PET/ictal SPECT in 4/5 SF and 4/4 NSF, with febrile seizures in 2/5 SF and 1/4 NSF, with psychic auras in 2/5 SF and 2/4 NSF, and with significant IAP asymmetry scores in 2/5 SF and 0/4 NSF. The presence of 4 concordant localizing features for TLE predicted a class 1 outcome in every case and never resulted in surgical failure.
Temporal lobectomy is an appropriate treatment for patients with refractory localization epilepsy even when high-resolution brain MRI is normal. The need for intracranial electrodes commonly predicted a NSF outcome while those with at least 4 preoperative concordant lines of evidence suggesting TLE predicted a SF outcome.