Introduction: The improvement of intensive care and surgical intervention has allowed many patients to survive severe head injury, and previous studies have developed some clinical parameters which can predict the conscious and functional recovery. These included Glasgow coma scale (GCS), age, electroencephalogram (EEG), image findings, papillary response and light reflex, and somatosensory evoked potentials (SSEP). Among these tests, some had better sensitivity for unfavorable or favorable outcome. Hypothermia has been applied in patients of brain injury; however, the rhythmic variation and its prognostic value of brain temperature after head injury have never been studied.
Methods: This study describes diurnal brain temperature patterns in comatose patients hospitalized for head injury (n = 108). Temperature mesor, amplitude, and acrophase were estimated from recorded temperature measurements using cosinor analysis. The association of these patterns with clinical parameters, mortality, and 6-month functional outcome was examined.
Results: Analyzed by the cosinor analysis, 59.3% of the patients had presence of circadian rhythm in brain temperature in the first 72 hours. The mean mesor was 37.39 (±1.21) ºC. The amplitude was diminished with a mean of 0.28 (±0.25) ºC. Shift of temperature acrophase was also observed. Analyzed by multivariate logistic regression, the final best predictive model included initial GCS, age and circadian rhythm of brain temperature.
Conclusions: Analysis of brain temperature rhythm in traumatic brain injury provided additional predictive information in relation to outcome. Further research is needed to understand the pathophysiology of brain temperature regulation following head injury.
Patient Care: Measurement and analysis of brain temperature using ICP monitoring may help to predict long-term functional outcome in patients with traumatic brain injury.
Learning Objectives: 1.The characteristics of brain temperature rhythm in patients of traumatic brain injury.
2.The predictive value of brain temperature rhythm in patients of traumatic brain injury.