Why continuous EEG matters in the hospital
Many inpatients at risk for seizures develop nonconvulsive or subtle electrographic events that are easy to miss on brief routine studies. Continuous EEG (cEEG) extends observation so clinicians can detect rhythmic and periodic patterns that often precede or accompany seizures, guide antiseizure therapy, and inform prognosis and monitoring intensity. Interpreting cEEG still depends on trained readers and clinical context; structured scores help teams communicate risk and prioritize resources in a consistent way.
What the 2HELPS2B score is
The 2HELPS2B score is a weighted checklist derived from cEEG findings plus a single historical item. It estimates how likely a hospitalized adult is to have seizures on cEEG, based on patterns that emerged in the original derivation cohort. The total ranges from 0 to 7: one domain (brief ictal rhythmic discharges, BIRDs) contributes two points when present; five other domains contribute one point each when present.
The name is a mnemonic for the ingredients clinicians scan for on the tracing and in the chart: rhythmic/periodic EEG features, epileptiform activity, frequency characteristics, superimposed “plus” morphology, and background/history elements—operationalized into explicit pattern definitions for scoring.
How the score is built (domain by domain)
Each item below is intended to be applied only when a qualified reader agrees the pattern meets standard critical-care EEG terminology. The calculator simply adds points you assign; it does not replace raw-trace review.
Brief ictal rhythmic discharges (BIRDs) — 2 points
BIRDs are short runs of evolving rhythmic activity that are concerning for an ictal pattern on cEEG. Because they sit closest to electrographic seizure activity among the scored items, BIRDs receive double weight (+2). When BIRDs are present, teams usually treat the recording as high acuity regardless of other score components.
LPDs, LRDA, or BIPDs — 1 point
This item captures three major lateralized or bilateral independent periodic/rhythmic categories used in ICU EEG reporting:
- Lateralized periodic discharges (LPDs)
- Lateralized rhythmic delta activity (LRDA)
- Bilateral independent periodic discharges (BIPDs)
If any qualifying pattern is present, the domain scores +1. These patterns are associated with irritative cerebral networks and increased seizure risk in many critically ill populations, though their implications also depend on etiology, medications, and temporal evolution.
History of seizures or epilepsy — 1 point
A documented history of clinical seizures or a diagnosis of epilepsy relevant to the admission adds +1. This acknowledges that baseline epileptogenic susceptibility and prior network injury can lower the threshold for electrographic events even when the acute tracing is ambiguous.
Sporadic epileptiform discharges — 1 point
Intermittent spikes, sharp waves, or spike-and-wave discharges that do not meet criteria for the sustained periodic or rhythmic runs scored elsewhere earn +1. These discharges mark focal or multifocal cortical hyperexcitability and often prompt closer inspection for evolution into rhythmic runs or seizures.
Periodic or rhythmic pattern frequency > 2.0 Hz — 1 point
Faster repetition rates of qualifying periodic or rhythmic patterns have been linked to higher seizure risk in multiple critical-care EEG contexts. This item adds +1 when a pattern that counts toward the score repeats at a rate greater than 2.0 Hz. Readers should apply this to the same patterns that are actually contributing to the score, not to unrelated background rhythms.
“Plus” features — 1 point
“Plus” refers to superimposed rhythmic, sharp, or fast activity riding on an underlying periodic or rhythmic pattern—morphology that suggests additional superimposed epileptiform or ictal-like sharpening. When present on a scored background pattern, it adds +1. This feature captures dynamic worsening that may be clinically important even before discrete seizures are annotated.
Total score and approximate risk bands
Add all applicable points. The maximum is 7 (2 for BIRDs plus up to five single-point items). Published estimates from the derivation work are often summarized as approximate seizure probabilities on cEEG, as in the following table. These percentages describe group-level risk in the studied population; they are not a literal personal probability for every patient you treat.
| Total score | Approximate seizure probability (derivation cohort) | Typical risk band label |
|---|---|---|
| 0 | ~5% | Very low |
| 1 | ~12% | Low |
| 2 | ~27% | Moderate |
| 3 | ~50% | High |
| 4 | ~73% | High |
| 5 | ~88% | Very high |
| 6–7 | >95% | Very high |
Using the score alongside monitoring decisions
Many pathways discuss how long to continue cEEG in relation to the total score—for example, favoring shorter minimum recording when the score is 0 and longer observation when the score is 2 or higher—always together with the indication for monitoring, institutional policy, and bedside changes in exam or labs. The score is best viewed as a shared language between neurophysiology, neurology, and the primary team rather than a stand-alone order.
When scores are higher, practical responses often include ensuring appropriate seizure precautions, reviewing antiseizure medications and reversible triggers (metabolic, infectious, ischemic, toxic), and coordinating escalation or de-escalation of monitoring with goals of care.
Important limitations
- Reader dependence: Mislabeling LPD versus artifact, mis-estimating repetition frequency, or disagreeing on whether activity qualifies as BIRDs will change the score materially.
- Population shift: Performance differs across settings (for example, acute brain injury units versus broader medical wards). External validation cohorts may show different calibration.
- Incomplete risk model: The score does not encode every seizure risk factor—sedative titration, recent strokes, subarachnoid blood, sepsis, specific drug exposures, and structural lesions may matter independent of the checklist.
- Not a treatment algorithm: The score informs probability and triage thinking; therapy choices remain individualized.
Disclaimer: This material supports clinical education. It does not replace qualified EEG interpretation, neurology or neurophysiology consultation, or institutional protocols.