Magnetoencephalography and ictal SPECT in patients with failed epilepsy surgery
(2018) Clinical Neurophysiology — Vol. 129, n° 8, p. 1651-1657 (2018)
Files
EltahryClinNeuroPhyFinal.pdf
Open Access - Adobe PDF
- 727.12 KB
Details
- Authors
- Abstract
- (en) OBJECTIVE: Selected patients with intractable focal epilepsy who have failed a previous epilepsy surgery can become seizure-free with reoperation. Preoperative evaluation is exceedingly challenging in this cohort. We aim to investigate the diagnostic value of two noninvasive approaches, magnetoencephalography (MEG) and ictal single-photon emission computed tomography (SPECT), in patients with failed epilepsy surgery. METHODS: We retrospectively included a consecutive cohort of patients who failed prior resective epilepsy surgery, underwent re-evaluation including MEG and ictal SPECT, and had another surgery after the re-evaluation. The relationship between resection and localization from each test was determined, and their association with seizure outcomes was analyzed. RESULTS: A total of 46 patients were included; 21 (46%) were seizure-free at 1-year followup after reoperation. Twenty-seven (58%) had a positive MEG and 31 (67%) had a positive ictal SPECT. The resection of MEG foci was significantly associated with seizure-free outcome (p = 0.002). Overlap of ictal SPECT hyperperfusion zones with resection was significantly associated with seizure-free outcome in the subgroup of patients with injection time ≤20 seconds(p = 0.03), but did not show significant association in the overall cohort (p = 0.46) although all injections were ictal. Patients whose MEG and ictal SPECT were concordant on a sublobar level had a significantly higher chance of seizure freedom (p = 0.05). ONCLUSIONS: MEG alone achieved successful localization in patients with failed epilepsy surgery with a statistical significance. Only ictal SPECT with early injection (≤20 seconds) had good localization value. Sublobar concordance between both tests was significantly associated with seizure freedom. SPECT can provide essential information in MEG-negative cases and vice versa. SIGNIFICANCE: Our results emphasize the importance of considering a multimodal presurgical evaluation including MEG and SPECT in all patients with a previous failed epilepsy surgery.
- Affiliations
Citations
El Tahry, R., Wang, Z. I., Thandar, A., Podkorytova, I., Krishnan, B., Tousseyn, S., Guiyun, W., Burgess, R. C., & Alexopoulos, A. V. (2018). Magnetoencephalography and ictal SPECT in patients with failed epilepsy surgery. Clinical Neurophysiology, 129(8), 1651-1657. https://doi.org/10.1016/j.clinph.2018.05.010 (Original work published 2018)