Stimulus-induced EEG-patterns and outcome after cardiac arrest

N Jaffer Broman; S Backman; E Westhall

doi:10.1016/j.cnp.2021.07.001

Stimulus-induced EEG-patterns and outcome after cardiac arrest

Clin Neurophysiol Pract. 2021 Jul 21:6:219-224. doi: 10.1016/j.cnp.2021.07.001. eCollection 2021.

Authors

N Jaffer Broman¹, S Backman¹, E Westhall¹

Affiliation

¹ Lund University, Skane University Hospital, Department of Clinical Sciences, Clinical Neurophysiology, Lund, Sweden.

Abstract

Objective: EEG is commonly used to predict prognosis in post anoxic coma. We investigated if stimulus-induced rhythmic, periodic or ictal discharges (SIRPIDs) add prognostic information after cardiac arrest.

Methods: In the multicenter Targeted Temperature Management trial, routine-EEGs were prospectively recorded after rewarming (≥36 h). Presence and subtype of SIRPIDs and main EEG-pattern (benign, malignant, highly malignant) were retrospectively reported according to a standardised classification. Patients were followed up after 180 days. Poor outcome was defined as severe neurological disability or death (Cerebral Performance Category 3-5).

Results: Of 142 patients, 71% had poor outcome and 14% had SIRPIDs. There was no significant difference in outcome between patients with and without SIRPIDs, even when subgrouped according to underlying main EEG-pattern. Comparing subtypes of SIRPIDs, 82% of patients with stimulus-induced periodic discharges had poor outcome compared to 44% of patients with stimulus-induced rhythmic delta activity, but the difference was not significant.

Conclusions: In EEGs performed ≥36 h after cardiac arrest, SIRPIDs cannot be used to reliably predict poor outcome. Whether certain subtypes of SIRPIDs indicate worse prognosis needs further investigation.

Significance: Categorising the main EEG-pattern has important prognostic implications, but assessment of late appearing SIRPIDs does not seem to add prognostic information.

Keywords: ACNS, American Clinical Neurophysiology Society; CPC, Cerebral Performance Category; Cardiac arrest; Coma; EEG; IQR, interquartile range; NSE, neuron-specific enolase; Prognosis; SI-PD, stimulus-induced periodic discharges; SI-RDA, stimulus-induced rhythmic delta activity; SI-SW, stimulus-induced spike-/polyspike-/sharp-and-waves; SI-Seizures, stimulus-induced unequivocal seizures; SIRPIDs; SIRPIDs, stimulus-induced rhythmic, periodic or ictal discharges; TTM, targeted temperature management.