Predicting the Unpredictable: Stereotactic Radiosurgery and Temporal Lobe Epilepsy
- 21 October 2010
- journal article
- Published by SAGE Publications in Epilepsy Currents
- Vol. 10 (6), 150-152
- https://doi.org/10.1111/j.1535-7511.2010.01385.x
Abstract
Predictors of Efficacy After Stereotactic Radiosurgery for Medial Temporal Lobe Epilepsy. Chang EF, Quigg M, Oh MC, Dillon WP, Ward MM, Laxer KD, Broshek DK, Barbaro NM; Epilepsy Radiosurgery Study Group. Neurology 2010;74(2):165–172. BACKGROUND: Stereotactic radiosurgery (RS) is a promising treatment for intractable medial temporal lobe epilepsy (MTLE). However, the basis of its efficacy is not well understood. METHODS: Thirty patients with MTLE were prospectively randomized to receive 20 or 24 Gy 50% isodose RS centered at the amygdala, 2 cm of the anterior hippocampus, and the parahippocampal gyrus. Posttreatment MRI was evaluated quantitatively for abnormal T2 hyperintensity and contrast enhancement, mass effect, and qualitatively for spectroscopic and diffusion changes. MRI findings were analyzed for potential association with radiation dose and seizure remission (Engel Ib or better outcome). RESULTS: Despite highly standardized dose targeting, RS produced variable MRI alterations. In patients with multiple serial imaging, the appearance of vasogenic edema occurred approximately 9–12 months after RS and correlated with onset of seizure remission. Diffusion and spectroscopy-detected alterations were consistent with a mechanism of temporal lobe radiation injury mediated by local vascular insult and neuronal loss. The degree of these early alterations at the peak of radiographic response was dose-dependent and predicted long-term seizure remission in the third year of follow-up. Radiographic changes were not associated with neurocognitive impairments. CONCLUSIONS: Temporal lobe stereotactic radiosurgery resulted in significant seizure reduction in a delayed fashion which appeared to be well-correlated with structural and biochemical alterations observed on neuroimaging. Early detected changes may offer prognostic information for guiding management.Keywords
This publication has 7 references indexed in Scilit:
- Predictors of efficacy after stereotactic radiosurgery for medial temporal lobe epilepsyNeurology, 2010
- A multicenter, prospective pilot study of gamma knife radiosurgery for mesial temporal lobe epilepsy: Seizure response, adverse events, and verbal memoryAnnals of Neurology, 2009
- Epilepsy related to hypothalamic hamartomas: surgical management with special reference to gamma knife surgeryChild's Nervous System, 2006
- Chronic epilepsy and cognition: A longitudinal study in temporal lobe epilepsyAnnals of Neurology, 2003
- Predicting verbal memory decline following anterior temporal lobectomy (ATL)Neurology, 2003
- Effects of Stereotactic Radiosurgery on an Animal Model of Hippocampal EpilepsyNeurosurgery, 2000
- Effects of stereotactic radiosurgery on an animal model of hippocampal epilepsy.2000