Development and Validation of the 5-SENSE Score to Predict Focality of the Seizure-Onset Zone as Assessed by Stereoelectroencephalography

Abstract

IMPORTANCE Stereoelectroencephalography (SEEG) has become the criterion standard in case of inconclusive noninvasive presurgical epilepsy workup. However, up to 40% of patients are subsequently not offered surgery because the seizure-onset zone is less focal than expected or cannot be identified.OBJECTIVE To predict focality of the seizure-onset zone in SEEG, the 5-point 5-SENSE score was developed and validated. DESIGN, SETTING, AND PARTICIPANTS This was a monocentric cohort study for score development followed by multicenter validation with patient selection intervals between February 2002 to October 2018 and May 2002 to December 2019. The minimum follow-up period was 1 year. Patients with drug-resistant epilepsy undergoing SEEG at the Montreal Neurological Institute were analyzed to identify a focal seizure-onset zone. Selection criteria were 2 or more seizures in electroencephalography and availability of complete neuropsychological and neuroimaging data sets. For validation, patients from 9 epilepsy centers meeting these criteria were included. Analysis took place between May and July 2021. MAIN OUTCOMES AND MEASURES Based on SEEG, patients were grouped as focal and nonfocal seizure-onset zone. Demographic, clinical, electroencephalography, neuroimaging, and neuropsychology data were analyzed, and a multiple logistic regression model for developing a score to predict SEEG focality was created and validated in an independent sample. RESULTS A total of 128 patients (57 women [44.5%]; median [range] age, 31 [13-58] years) were analyzed for score development and 207 patients (97 women [46.9%]; median [range] age , 32 [16-70] years) were analyzed for validation. The score comprised the following 5 predictive variables: focal lesion on structural magnetic resonance imaging, absence of bilateral independent spikes in scalp electroencephalography, localizing neuropsychological deficit, strongly localizing semiology, and regional ictal scalp electroencephalography onset. The 5-SENSE score had an optimal mean (SD) probability cutoff for identifying a focal seizure-onset zone of 37.6 (3.5). Area under the curve, specificity, and sensitivity were 0.83, 76.3% (95% CI, 66.7-85.8), and 83.3% (95% CI, 72.30-94.1), respectively. Validation showed 76.0% (95% CI, 67.5-84.0) specificity and 52.3% (95% CI, 43.0-61.5) sensitivity. CONCLUSIONS AND RELEVANCEHigh specificity in score development and validation confirms that the 5-SENSE score predicts patients where SEEG is unlikely to identify a focal seizure-onset zone. It is a simple and useful tool for assisting clinicians to reduce unnecessary invasive diagnostic burden on patients and overutilization of limited health care resources.

Nomograms Should Not Be Used by General Neurologists When Considering Referral for Epilepsy Surgery

“…Using a similar stepwise approach to identify predictors of resective surgery and subsequent seizure freedom in patients studied with iEEG, Sivaraju et al 4 ( using data that predates my association with the Yale group ) report on a retrospective analysis of 178 consecutive patients who underwent iEEG followed by resection in 116 and with 5-year follow-up. Multivariable analysis identified variables, comparable to what Astner-Rohracher et al 3 report, as independent predictors of resection and absolute seizure freedom at 5-year follow-up. Importantly, some patients thought to have unfavorable predictors, such as nonlesional MRI, had a greater than 50% chance of seizure freedom if they underwent resection.…”

“…In the current study by Astner-Rohracher et al, 3 the authors suggest a nomogram that can identify patients who might benefit from stereoelectroencephalography (SEEG). Using data from 128 consecutive patients, they identified factors that predicted focality on SEEG, which were seen in 37.5% of cases.…”

Intracranial EEG Structure-Function Coupling and Seizure Outcomes After Epilepsy Surgery

“…46 Our recent work benchmarked noninvasive surgical outcome measures against 13 clinical variables, 10 which we also incorporate in this study to demonstrate the added value of new measures over routine clinical variables. We envision combining these multimodal measures with unimodal measures from structural or functional imaging modalities and presurgical clinical data into a software tool 41 for identifying individuals who are less likely to achieve seizure freedom.…”

“…First, our results can aid in identifying the focality of iEEG implantation. 41 We generated patient-specific maps of the relationship between structural and functional brain networks, which classified the brain tissue under each iEEG contact as either a coupling booster or damper. Epileptogenic tissues (i.e., resections in seizure-free patients) were identified by the presence of coupling boosters.…”

Passive and active markers of cortical excitability in epilepsy

“…95,96 Next, one approach to translation is to build an easy-to-use tool for clinicians to predict important clinical outcomes, such as the 5-SENSE score, which incorporates scalp EEG spikes and other features to predict focality of the seizure onset zone. 97 We can also package quantitative algorithms into submodules of commonly used commercial software, putting sophisticated techniques into the hands of clinicians. We may ultimately need prospective, randomized controlled trials, testing whether incorporating these biomarkers into surgical decision-making improves outcomes.…”