Quantitative EEG and Effect of Hypothermia on Brain Recovery After Cardiac Arrest

Shin, Hyun-Chool; Tong, Shanbao; Yamashita, Soichiro; Jia, Xiaofeng; Geocadin, G.; Thakor, Nitish V.

doi:10.1109/tbme.2006.873394

Cited by 50 publications

(61 citation statements)

References 20 publications

(34 reference statements)

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“…The asphyxial CA and cardiopulmonary resuscitation (CPR) model used previously validated protocols (23,26,30). In brief (detail described by Jia et al (23)), rats were mechanically ventilated with 1.0% Halothane in N 2 /O 2 (50%/50%).…”

Section: Experimental Asphyxia-cardiac Arrest Modelmentioning

confidence: 99%

“…Hypothermia or hyperthermia was induced immediately after ROSC. Hypothermia was achieved through surface cooling with misted water to achieve the target temperature of 33°C within 15 mins (23,30). The core temperature was maintained between 32 and 34°C for 6 hours.…”

Section: Immediate Temperature Manipulation After Cardiac Arrestmentioning

confidence: 99%

“…As a result of this analyses, which has been described previously (23,30), we obtained normalized EEG values that range from 1.0 (control) to 0.0 (isoelectricity). IQ is normalized to baseline values, such that higher values reflect greater EEG entropy relative to baseline.…”

Section: Eeg Recording and Quantitative Eeg Analysismentioning

confidence: 99%

“…We developed the theoretical measure information quantity (IQ) to provide an objective measure of entropy in EEG amplitude (30). Our subsequent work showed that greater injury was associated with lower entropy and reduced IQ values.…”

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confidence: 99%

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Early electrophysiologic markers predict functional outcome associated with temperature manipulation after cardiac arrest in rats

Jia

Koenig

Nickl

et al. 2008

Critical Care Medicine

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Objective-Therapeutic hypothermia after cardiac arrest improves survival and functional outcomes, whereas hyperthermia is harmful. The optimal method of tracking the effect of temperature on neurologic recovery after cardiac arrest has not been elucidated. We studied the recovery of cortical electrical function by quantitative electroencephalography after 7-min asphyxial cardiac arrest, using information quantity (IQ). Design-Laboratory investigation.Setting-University medical school and animal research facility. Subjects-A total of 28 male Wistar rats.Interventions-Using an asphyxial cardiac arrest rodent model, we tracked quantitative electroencephalography of 6-hr immediate postresuscitation hypothermia (at 33°C), normothermia (37°C), or hyperthermia (39°C) (N=8 per group). Neurological recovery was evaluated using the Neurological Deficit Score. Four rats were included as a sham control group. Measurements and MainResults-Greater recovery of IQ was found in rats treated with hypothermia (IQ=0.74), compared to normothermia (IQ=0.60) and hyperthermia (IQ=0.56) (p<. 001). Analysis at different intervals demonstrated a significant separation of IQ scores among the temperature groups within the first 2 hrs postresuscitation (p<.01). IQ values of >0.523 at 60 mins postresuscitation predicted good neurological outcome (72-hr Neurological Deficit Score of≥60) with a specificity of 100% and sensitivity of 81.8%. IQ was also significantly lower in rats that died prematurely compared to survivors (p<.001). IQ values correlated strongly with 72-hr Neurological Deficit Score as early as 30 mins post-cardiac arrest (Pearson correlation 0.735, p<.01) and maintained a significant association throughout the 72-hr experiment. No IQ difference was noted in sham rats with temperature manipulation. Approximately 164,600 cardiac arrests (CAs) occur in the United States each year (1). Among initial survivors, 80% remain comatose after resuscitation (2) and neurological complications represent the leading cause of disability (3,4). The ischemic brain is sensitive to temperature, such that small differences can critically influence neuropathological outcomes (5). Hyperthermia has been demonstrated to worsen ischemic outcome and is associated with increased brain injury in animal models (5,6) and clinical studies (7-9). On the other hand, induced hypothermia to 32-34°C is recommended for comatose survivors of CA (10,11) and was recently shown to significantly mitigate brain injury in animal models (12)(13)(14) and clinical trials (15-18). NIH Public AccessNeurological monitoring of comatose CA survivors is complicated by the requirement for sedative and paralytic agents, particularly in patients who are treated with hypothermia. Comatose CA survivors are typically cared for by nurses and physicians in general or cardiac intensive care units with little specialized training in neurological examination. In addition, the ability to detect even major changes in brain function in comatose patients is limited. Electroencephalograp...

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Section: Experimental Asphyxia-cardiac Arrest Modelmentioning

confidence: 99%

Section: Immediate Temperature Manipulation After Cardiac Arrestmentioning

confidence: 99%

Section: Eeg Recording and Quantitative Eeg Analysismentioning

confidence: 99%

mentioning

confidence: 99%

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Early electrophysiologic markers predict functional outcome associated with temperature manipulation after cardiac arrest in rats

Jia

Koenig

Nickl

et al. 2008

Critical Care Medicine

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“…The core temperature was maintained at 37°C -0.5°C with the help of a heating pad for 1 hour after the time of contusion or laminectomy and prior to inducing hypothermia. After 1 hour, general hypothermia was induced by spraying the rat with alcohol mist (70% ethanol) and using an electric fan until the core temperature dropped to 32°C -0.5°C, as previously described (Shin et al, 2006;Jia et al, 2008;Maybhate et al, 2012). The induction period lasted 25 to 30 minutes.…”

Section: Induction Of General Hypothermiamentioning

confidence: 99%

The Effects of Local and General Hypothermia on Temperature Profiles of the Central Nervous System Following Spinal Cord Injury in Rats

Bazley

Pashai²,

Kerr

et al. 2014

Therapeutic Hypothermia and Temperature Management

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Local and general hypothermia are used to treat spinal cord injury (SCI), as well as other neurological traumas. While hypothermia is known to provide significant therapeutic benefits due to its neuroprotective nature, it is unclear how the treatment may affect healthy tissues or whether it may cause undesired temperature changes in areas of the body that are not the targets of treatment. We performed 2-hour moderate general hypothermia (32°C core) or local hypothermia (30°C spinal cord) on rats that had received either a moderate contusive SCI or laminectomy (control) while monitoring temperatures at three sites: the core, spinal cord, and cortex. First, we identified that injured rats that received general hypothermia exhibited larger temperature drops at the spinal cord (-3.65°C, 95% confidence intervals [CIs] -3.72, -3.58) and cortex ( -3.64°C, CIs -3.73, -3.55) than uninjured rats (spinal cord: -3.17°C, CIs -3.24, -3.10; cortex: -3.26°C, CIs -3.34, -3.17). This was found due to elevated baseline temperatures in the injured group, which could be due to inflammation. Second, both general hypothermia and local hypothermia caused a significant reduction in the cortical temperature (-3.64°C and -1.18°C, respectively), although local hypothermia caused a significantly lower drop in cortical temperature than general hypothermia ( p < 0.001). Lastly, the rates of rewarming of the cord were not significantly different among the methods or injury groups that were tested; the mean rate of rewarming was 0.13 -0.1°C/ min. In conclusion, local hypothermia may be more suitable for longer durations of hypothermia treatment for SCI to reduce temperature changes in healthy tissues, including the cortex.

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Hyperacute autonomic and cortical function recovery following cardiac arrest resuscitation in a rodent model

Guo,

Gharibani,

Agarwal

et al. 2023

Ann Clin Transl Neurol

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ObjectiveThere is a complex interaction between nervous and cardiovascular systems, but sparse data exist on brain–heart electrophysiological responses to cardiac arrest resuscitation. Our aim was to investigate dynamic changes in autonomic and cortical function during hyperacute stage post‐resuscitation.MethodsTen rats were resuscitated from 7‐min cardiac arrest, as indicators of autonomic response, heart rate (HR), and its variability (HRV) were measured. HR was monitored through continuous electrocardiography, while HRV was assessed via spectral analysis, whereby the ratio of low−/high‐frequency (LF/HF) power indicates the balance between sympathetic/parasympathetic activities. Cortical response was evaluated by continuous electroencephalography and quantitative analysis. Parameters were quantified at 5‐min intervals over the first‐hour post‐resuscitation. Neurological outcome was assessed by Neurological Deficit Score (NDS, range 0–80, higher = better outcomes) at 4‐h post‐resuscitation.ResultsA significant increase in HR was noted over 15–30 min post‐resuscitation (p < 0.01 vs.15‐min, respectively) and correlated with higher NDS (rs = 0.56, p < 0.01). LF/HF ratio over 15–20 min was positively correlated with NDS (rs = 0.75, p < 0.05). Gamma band power surged over 15–30 min post‐resuscitation (p < 0.05 vs. 0–15 min, respectively), and gamma band fraction during this period was associated with NDS (rs ≥0.70, p < 0.05, respectively). Significant correlations were identified between increased HR and gamma band power during 15–30 min (rs ≥0.83, p < 0.01, respectively) and between gamma band fraction and LF/HF ratio over 15–20 min post‐resuscitation (rs = 0.85, p < 0.01).InterpretationsHyperacute recovery of autonomic and cortical function is associated with favorable functional outcomes. While this observation needs further validation, it presents a translational opportunity for better autonomic and neurologic monitoring during early periods post‐resuscitation to develop novel interventions.

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Quantitative EEG and Effect of Hypothermia on Brain Recovery After Cardiac Arrest

Cited by 50 publications

References 20 publications

Early electrophysiologic markers predict functional outcome associated with temperature manipulation after cardiac arrest in rats

Early electrophysiologic markers predict functional outcome associated with temperature manipulation after cardiac arrest in rats

The Effects of Local and General Hypothermia on Temperature Profiles of the Central Nervous System Following Spinal Cord Injury in Rats

Hyperacute autonomic and cortical function recovery following cardiac arrest resuscitation in a rodent model

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