Predict the neurological recovery under hypothermia after cardiac arrest using C0 complexity measure of EEG signals

Clinical trials have proven the efficacy of therapeutic hypothermia in improving the functional outcome after cardiac arrest (CA) compared with the normothermic controls. Experimental researches also demonstrated quantitative electroencephalogram (qEEG) analysis was associated with the long-term outcome of the therapeutic hypothermia in brain injury. Nevertheless, qEEG has not been able to provide a prediction earlier than 6h after the return of spontaneous circulation (ROSC). In this study, we use C0 complexity to analyze the nonlinear characteristic of EEG, which could predict the neurological recovery under therapeutic hypothermia during the early phase after asphyxial cardiac arrest in rats. Twelve Wistar rats were randomly assigned to 9-min asphyxia injury under hypothermia (33°C, n=6) or normothermia (37°C, n=6). Significantly greater C0 complexity was found in hypothermic group than that in normothermic group as early as 4h after the ROSC (P<0.05). C0 complexity at 4h correlated well with the 72h neurodeficit score (NDS) (Pearson's correlation = 0.882). The results showed that the C0 complexity could be an early predictor of the long-term neurological recovery from cardiac arrest.

[1]  M H Weil,et al.  Therapeutic hypothermia after cardiac arrest: an advisory statement by the advanced life support task force of the International Liaison Committee on Resuscitation. , 2003, Circulation.

[2]  Schuster,et al.  Easily calculable measure for the complexity of spatiotemporal patterns. , 1987, Physical review. A, General physics.

[3]  Nitish V. Thakor,et al.  Quantitative EEG and effect of hypothermia on brain recovery after cardiac arrest , 2006, IEEE Transactions on Biomedical Engineering.

[4]  Shanbao Tong,et al.  Advances in quantitative electroencephalogram analysis methods. , 2004, Annual review of biomedical engineering.

[5]  Cai Zhi-jie,et al.  Mathematical foundation of a new complexity measure , 2005 .

[6]  P. Safar,et al.  Lightning stroke. Report of a case with recovery after cardiac massage and prolonged artificial respiration. , 1961, The New England journal of medicine.

[7]  Nitish V. Thakor,et al.  Quantitative EEG and neurological recovery with therapeutic hypothermia after asphyxial cardiac arrest in rats , 2006, Brain Research.

[8]  F. Spencer,et al.  THE USE OF HYPOTHERMIA AFTER CARDIAC ARREST , 1959, Anesthesia and analgesia.

[9]  A. Detsky,et al.  Cost-effectiveness analysis of potential improvements to emergency medical services for victims of out-of-hospital cardiac arrest. , 1996, Annals of emergency medicine.

[10]  Alan D. Lopez,et al.  Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest. , 2002, The New England journal of medicine.

[11]  F C SPENCER,et al.  The clinical use of hypothermia following cardiac arrest. , 1959, Annals of surgery.

[12]  P Vaagenes,et al.  Cerebral resuscitation from cardiac arrest: pathophysiologic mechanisms. , 1996, Critical care medicine.

[13]  F Aichner,et al.  The prognostication of cerebral hypoxia after out-of-hospital cardiac arrest in adults. , 1997, European neurology.

[14]  Abraham Lempel,et al.  On the Complexity of Finite Sequences , 1976, IEEE Trans. Inf. Theory.

[15]  EEG complexity measurement of focal ischemic cerebral injury , 1998, Proceedings of the 20th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. Vol.20 Biomedical Engineering Towards the Year 2000 and Beyond (Cat. No.98CH36286).

[16]  S. Coons,et al.  Stability and autolysis of cortical neurons in post-mortem adult rat brains. , 2008, International journal of clinical and experimental pathology.