Intraoperative Imaging and Surgical Outcome in Temporal Lobe Epilepsy.
Abstract number :
2.316
Submission category :
Year :
2001
Submission ID :
1194
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
B.E. Swartz, MD, PhD, Neurology, University Hospital- Case Western Univ., Cleveland, OH; A. Metzger, MD, Neurosurgery, University Hospital-Case Western, Cleveland, OH; S. Robinson, MD, Neurosurgery, University Hospital-Case Western, Cleveland, OH; M. Werz
RATIONALE: While many factors contribute to successful outcomes of temporal lobe surgery (TLS), one appears to be the extent of hippocampal (HC)resection. Since beginning a surgery program 17 months ago, we have had the availability of intraoperative MRI (IOMR) on most temporal resections. We have evaluated our findings to date on non-tumoral cases only.
METHODS: Six of 8 adults and 4 of 4 children had IOMR, 1 adult had IO imaging with the Stealth system. A standard anterior temporal lobectomy with variable cortical resection was used in all, with a subpial amygdalo-hippocampectomy. A single IOMR was made after the surgeon had resected medial structures, and a second IOMR was then made. If more resection was done a final IOMR was performed at the end of the surgery to verify extent of HC resection. The scans were made with an imaging coil using T2 weighted, fast spin echo and FLAIR sequences in axial, sagittal and coronal planes with special attention the the hippocampal anatomy. HC measurments were taken from the IOMR and post-op MRI[ssquote]s.
RESULTS: In all cases in which the surgeon thought the hippocampus resection was satisfactory, the IOMR showed persisting HC, and more was able to be removed. HC resection ranged from 2 cm in one patient in whom the IOMR failed due to technical problems to 5.5 cm, mean 3.9 cm. Outcome is less than 6 months in two. In the rest, 8/9 who had IOM are seizure free except for a single breakthrough seizure when anticonvulsants were discontinued abrubtly in one. 1/9 has had two seizures of non-temporal origin, related to a post-operative CVA, but has been seizure free 9 months. In the patient with the smallest HC resection and failed IOMR, an 80% decrease has been achieved. Follow-up is 8-17 mo (mean 11.7 mo.)
CONCLUSIONS: Intraoperative MR can determine the true extent of hippocampal excision and guide the surgical planning. It may improve surgical outcomes, although our series is still too small and too early to conclude this. More patients and outcome data will be presented.