Prognostic significance of clinical seizures after cardiac arrest and target temperature management.
Clinical seizures are common after cardiac arrest and predictive of a poor neurological outcome. Seizures may be myoclonic, tonic-clonic or a combination of seizure types. This study reports the incidence and prognostic significance of clinical seizures in the target temperature management (TTM) after cardiac arrest trial. Our hypotheses were that seizures are associated with a poor prognosis and that the incidence of seizures is not affected by the target temperature.



Post-hoc analysis of reported clinical seizures during day 1-7 in the TTM-trial including their treatment, EEG-findings, and long-term neurological outcome. The trial randomised 939 comatose survivors to TTM at 33°C or 36°C with strict criteria for withdrawal of life-sustaining therapies. Sensitivity, specificity and false positive rate for poor outcome were reported for different types of seizures.



Clinical seizures were registered in 268 patients (29%), similarly distributed in both intervention arms. Early and late seizures were equally predictive of poor outcome. Myoclonic seizures were the most common (240 patients, 26%) and the most predictive of a poor outcome (sensitivity 36.1%, false positive rate 4.3%). Two patients with status myoclonus regained consciousness, one with a good neurological outcome, generating a false positive rate of poor outcome of 0.2% (95%CI 0.0-1.0).



Clinical seizures are common after cardiac arrest and indicate poor outcome with limited specificity. Prolonged seizures are a very grave sign but occasional patients may have a good outcome. The level of the target temperature does not affect the prevalence or prognostic significance of seizures.
Lund University, Skane University Hospital, Department of Clinical Sciences Lund, Department of Anesthesia & Intensive Care, Lund 221 85, Sweden. Electronic address: anna.lybeck@med.lu.se.
Anna
A
Lybeck
Lund University, Skane University Hospital, Department of Clinical Sciences Lund, Department of Anesthesia & Intensive Care, Lund 221 85, Sweden. Electronic address: hans.a.friberg@gmail.com.
Hans
H
Friberg
Intensive Care Unit, Liverpool Hospital, South Western Sydney Local Health District, Elizabeth Street, Liverpool, Sydney, NSW 2170, Australia. Electronic address: Anders.Aneman@sswahs.nsw.gov.au.
Anders
A
Aneman
Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark. Electronic address: hassager@dadlnet.dk.
Christian
C
Hassager
Department of Intensive Care, Academic Medical Center, Postbus 22660, Amsterdam 1100 DD, Netherlands. Electronic address: j.horn@amc.uva.nl.
Janneke
J
Horn
Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark. Electronic address: jesper.kjaergaard.05@regionh.dk.
Jesper
J
Kjærgaard
Department of Intensive Care, Medical Center Leeuwarden, Henri Dunantweg 2, Leeuwarden 8934 AD, Netherlands. Electronic address: mi.kuiper@wxs.nl.
Michael
M
Kuiper
Lund University, Helsingborg Hospital, Department of Clinical Sciences Lund, Department of Anesthesia & Intensive Care, Helsingborg, Lund 251 87, Sweden. Electronic address: niklas.nielsen@telia.com.
Niklas
N
Nielsen
Clinical Studies Sweden - Forum South, R&D Centre Skane, Skane University Hospital, Lund 221 85, Sweden. Electronic address: susann.ullen@skane.se.
Susann
S
Ullén
Adult Critical Care, University Hospital of Wales, Heath Park, Cardiff CF14 4XW, United Kingdom. Electronic address: mattwise@doctors.org.uk.
Matthew P
MP
Wise
Lund University, Skane University Hospital, Department of Clinical Sciences Lund, Clinical Neurophysiology, Lund 221 85, Sweden. Electronic address: erik.westhall@med.lu.se.
Erik
E
Westhall
Lund University, Skane University Hospital, Department of Clinical Sciences, Department of Neurology, Lund 221 85, Sweden. Electronic address: tobias.cronberg@skane.se.
Tobias
T
Cronberg
D000368:Aged; D001831:Body Temperature; D016887:Cardiopulmonary Resuscitation; D003128:Coma / Q000150:complications; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000150:complications / Q000628:therapy*; D012307:Risk Factors; D012640:Seizures / Q000145:classification* / Q000150:complications; D012680:Sensitivity and Specificity
Cardiac arrest; EEG; Myoclonus; Neurological prognostication; Seizures; Target temperature management