SUBTRACTION ICTAL SPECT CO-REGISTERED TO MRI (SISCOM) AND REOPERATION FOR INTRACTABLE EPILEPSY
Abstract number :
1.416
Submission category :
Year :
2003
Submission ID :
4063
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
Nicholas M. Wetjen, Gregory D. Cascino, Elson L. So, A. James Fessler, Brian P. Mullan, W. Richard Marsh, Fredric B. Meyer Department of Neurologic Surgery, Mayo Clinic, Rochester, MN; Department of Neurology, Mayo Clinic, Rochester, MN; Department of Nuc
Seizures persist or recur in 20-60% of patients who have undergone resection for intractable partial epilepsy. Techniques that predict likelihood of success for reoperation are needed because of the potential morbidity and cost associated with the presurgical evaluation and operative procedure. SISCOM has been shown to be a reliable indicator of the site of seizure onset in patients with intractable partial epilepsy. The diagnostic yield and prognostic importance of SISCOM in patients undergoing reoperation is not well known.
We performed a retrospective study and investigated SISCOM in patients who were surgical failures and were being evaluated for reoperation. SISCOM images were analyzed in 59 consecutive patients who underwent vide-EEG monitoring between January 1996 and October 1999 for possible reoperation. The mean age at the time of the imaging study was 29.7 years. Fifteen patients underwent subsequent chronic intracranial monitoring. Medical records, imaging studies, and surgical reports for these patients at initial evaluation and follow-up were reviewed.
The SISCOM study revealed a hyperperfusion focus in 46/59 patients (78.0%). Twenty-eight of these 46 (60.9%) foci were in the vicinity of the previous surgical site, whereas 13 (28.2%) were remote but in the same hemisphere. The hyperperfusion focus was in the contralateral hemisphere in the remaining 5 patients (10.9%). The site of the ictal EEG onset zone was concordant with the SISCOM focus in 37 of 46 (80.4%). Thirty-one patients underwent reoperation and were followed for a minimum of 6 months (mean 24 months). Ictal onset with intracranial EEG correlated with the hyperperfusion focus in 7 of 15 patients monitored (46.7%). Of the selected patients that underwent additional surgery without intracranial monitoring 11 of 16 (68.8%) had extension of their previous temporal lobectomy. Five of these 11 (45.4%) patients had Engel class 1-II at follow-up (average 27 months). Seven of the 9 patients (78.8%) with longer than 3 years follow-up experienced Engel Class I-II outcome.
SISCOM may be useful in patients with intractable partial epilepsy who are surgical failures and are being considered for reoperation.