A Novel method of seizure onset zone localization by serial Tc-99 m ECD brain perfusion SPECT clearance patterns

Abstract

In this prospective study, we postulate that there is a difference between clearance of [99mTc]Tc-ethyl cysteinate dimer (ECD) in the seizure onset zone (SOZ) and other brain areas and thus SOZ localization by clearance patterns might become a potential novel method for SOZ localization in epilepsy. The parametric images of brain ECD clearance were generated by linear regression model analysis from serial brain SPECT scans from 30 minutes to 240 minutes after ECD injection (7-times point) in 7 patients with drug-resistant epilepsy and 3 normal volunteers. Clearance patterns of the SOZ con rmed by good surgical outcome or consensus with other investigations were analyzed quantitatively and semi-quantitatively by visual grading (slower or faster washout than contralateral brain regions). The average [ 99m Tc]Tc-ECD clearance rates of SOZs were + 1.08 % ± 2.57 %/hr (wash in), -7.02 % ± 2.56 %/hr (washout), and − 5.37% ± 1.71 %/hr (washout) in ictal, aura and interictal states, respectively. Paired t-tests between the SOZ and contralateral regions showed statistically signi cant difference (p = 0.039 in interictal state). Clearance patterns that can de ne the SOZs were 1) wash in and slow washout on ictal slope, 2) fast washout on aura slope and interictal slope with 100% (6/6), 100% (2/2) and 75% (6/8) localization using ictal, aura, and interictal slope maps, respectively. Our study provided the evidence that clearance pattern methods are potential additive diagnostic tools for SOZ localization when routine one-time point SPECT are unable to de ne the SOZ.

The diagnostic value of ictal SPECT—A retrospective, semiquantitative monocenter study

“…Regarding seizure injection latencies, previous work showed inconsistent results. Whereas in some studies, short seizure injection latencies correlated with better VSA and ISAS outcomes, 16,28 other reports, including our current study, found no association between longer seizure injection latencies and poor VSA and ISAS outcomes 18,29 . This may detract from the dogma of immediate injection in ictal SPECT but is more likely due to the small number of cases with prolonged infusion latencies (>45 seconds) in our patient population.…”

“…Whereas in some studies, short seizure injection latencies correlated with better VSA and ISAS outcomes, 16 , 28 other reports, including our current study, found no association between longer seizure injection latencies and poor VSA and ISAS outcomes. 18 , 29 This may detract from the dogma of immediate injection in ictal SPECT but is more likely due to the small number of cases with prolonged infusion latencies (>45 seconds) in our patient population. In the general comparison, VSA and ISAS outperformed EEG in its ability to localize the SOZ but are less sensitive than MRI based on conventional radiological readings.…”

Dynamic 18F-FDG-PET kinetic parameters for epileptogenic zone localization in drug-resistant epilepsy

“…Improving the localization of epileptic foci in DRE is of great interest, as visualization of hypometabolic areas on FDG-PET is non-specific to the EZ [29,30]. In recent years, there have been huge efforts in using nuclear medicine techniques, both by visual and by quantitative analysis, for better localizing EZ [30].…”

Synthetic Epileptic Brain Activities with TripleGAN

“…EEG source localization is the problem of estimating the source of EEG activity from a given scalp EEG distribution, which is usually called the inverse problem of EEG. At present, the methods used to locate EEG activity sources mainly include equivalent current dipole (ECD) [16], sparse and Bayesian framework [17], beamforming and scanning algorithms [18], minimize L2 normal family [19], and nonlinear post hoc normalization [20]. In recent years, more researches have been made on introducing the timing pattern of the signal in the process of determining the position of the source signal [16][17][18].…”

“…At present, the methods used to locate EEG activity sources mainly include equivalent current dipole (ECD) [16], sparse and Bayesian framework [17], beamforming and scanning algorithms [18], minimize L2 normal family [19], and nonlinear post hoc normalization [20]. In recent years, more researches have been made on introducing the timing pattern of the signal in the process of determining the position of the source signal [16][17][18]. After introducing the time information, the adjacent temporal signals can provide more observation data for the underdetermined EEG inverse problem, thus compressing the solution space and making the inverse problem easier to solve.…”