Assessment of the Validity of the 2HELPS2B Score for Inpatient Seizure Risk Prediction

Abstract

IMPORTANCESeizure risk stratification is needed to boost inpatient seizure detection and to improve continuous electroencephalogram (cEEG) cost-effectiveness. 2HELPS2B can address this need but requires validation. OBJECTIVE To use an independent cohort to validate the 2HELPS2B score and develop a practical guide for its use. DESIGN, SETTING, AND PARTICIPANTSThis multicenter retrospective medical record review analyzed clinical and EEG data from patients 18 years or older with a clinical indication for cEEG and an EEG duration of 12 hours or longer who were receiving consecutive cEEG at 6 centers from January 2012 to January 2019. 2HELPS2B was evaluated with the validation cohort using the mean calibration error (CAL), a measure of the difference between prediction and actual results. A Kaplan-Meier survival analysis was used to determine the duration of EEG monitoring to achieve a seizure risk of less than 5% based on the 2HELPS2B score calculated on first-hour (screening) EEG. Participants undergoing elective epilepsy monitoring and those who had experienced cardiac arrest were excluded. No participants who met the inclusion criteria were excluded. MAIN OUTCOMES AND MEASURESThe main outcome was a CAL error of less than 5% in the validation cohort. RESULTSThe study included 2111 participants (median age, 51 years; 1113 men [52.7%]; median EEG duration, 48 hours) and the primary outcome was met with a validation cohort CAL error of 4.0% compared with a CAL of 2.7% in the foundational cohort (P = .13). For the 2HELPS2B score calculated on only the first hour of EEG in those without seizures during that hour, the CAL error remained at less than 5.0% at 4.2% and allowed for stratifying patients into low-(2HELPS2B = 0; <5% risk of seizures), medium-(2HELPS2B = 1; 12% risk of seizures), and high-risk (2HELPS2B, Ն2; risk of seizures, >25%) groups. Each of the categories had an associated minimum recommended duration of EEG monitoring to achieve at least a less than 5% risk of seizures, a 2HELPS2B score of 0 at 1-hour screening EEG, a 2HELPS2B score of 1 at 12 hours, and a 2HELPS2B score of 2 or greater at 24 hours.CONCLUSIONS AND RELEVANCE In this study, 2HELPS2B was validated as a clinical tool to aid in seizure detection, clinical communication, and cEEG use in hospitalized patients. In patients without prior clinical seizures, a screening 1-hour EEG that showed no epileptiform findings was an adequate screen. In patients with any highly epileptiform EEG patterns during the first hour of EEG (ie, a 2HELPS2B score of Ն2), at least 24 hours of recording is recommended.

Hyperperfusion in the thalamus on arterial spin labelling indicates non-convulsive status epilepticus

“…The cohort study of 2111 participants with continuous EEG showed that any highly epileptiform discharges during the first hour of EEG (i.e. a 2HELPS2B score of ≥2) indicated that at least 24 h of recording was recommended to detect seizures ( Struck et al , 2020 ). In 121 critically ill children, the first non-convulsive seizures were all captured within 24 h in 28 non-convulsive seizures ( McCoy et al , 2011 ).…”

“…Lateralized PDs regardless of frequencies and lateralized RDA with high frequencies are associated with seizures ( Rodriguez Ruiz et al ., 2017 ). Brief potentially ictal rhythmic discharges may indicate ictal–interictal continuum for consideration of the treatment of seizures ( Yoo et al , 2014 ; Struck et al , 2020 ). One of the ictal EEG criteria must persist for longer than 10 s under the Salzburg criteria ( Leitinger et al , 2016 ).…”

Does continuous electroencephalography influence therapeutic decisions in neurocritical care?

“…Our results confirm that SE is common in patients in neurocritical care, but the prevalence of seizure activity in this study is even higher than previously reported. A review of the literature on cEEG and detection of status epilepticus and seizures in adults published in the past 5 years are provided in Table 3 14,17–40 . 51–59 Most studies on seizures activity and cEEG performed in neurocritically ill patients are from the United States.…”

Epileptic Seizures in Critically Ill Patients: Diagnosis, Management, and Outcomes

“…Recent advances have enabled a better understanding of the global epidemiology of this entity [ 2 , 3 , 4 ]. The greater implementation of continuous EEG monitoring has certainly contributed to this [ 5 , 6 ].…”