| Section oneCorrelation between brainstem auditory evoked potential findings and awakening in long-term unconscious patients with traumatic brain injuryBackground Traumatic brain injury is a prevalent problem around the world which threatens the health of mankind. It is one of leading reasons of death and disability in young patients. Most prognosis are poor of patients who suffered Traumatic brain injury. That patients brought a heavy burden to the social and patients' families. Only 53.7%-63.0% patients recover consciousness after traumatic brain injury as reported, that is to so, another patients couldn't recover consciousness. If there are reliable indicators to predict prognosis, we can strengthen the treatment of that patient who could be awake in order to short the period of coma and recover consciousness early. We can end the treatment as soon as possible to patients who are prompted by indicators of poor prognosis. It takes a lot of social resources to maintain life support of unconscious patients. There aren't the statistics of domestic, it takes one to seven billion dollars to maintain patients who are coma or vegetative state each year In the United States. The prediction of prognosis is important to guide treatment. The families of patients can know the current situation and to make decision about life support as soon as possible. It can make use of medical resources in reason. It is more important to take early, objective and accurate prediction to coma patients with the development of medical ethics and in order to use medical resources more effectively. So how to establish an effective, reliable and practicable model to predict the probability of patients' awakening is an urgent issue. First, we can classify the patients according to the severity of the disease, and avoid the occurence of risk factors, this will greatly improve the level of our medical treatment in the future. Second, it can provide the accurate information of patients' disease, which can guide us making decision and is good for the allocation of medical resources. With the development of our society, more and more attention has been paid to this field, especially in the West. However our research is just in start level, so making a predictive model is essential for our country.Objective To explore the correlation between brainstem auditory evoked potential (BAEP) and awakening in long-term unconscious patients after severe traumatic brain injury (TBI).Methods The data were collected retrospectively in 63 patients suffering from severe TBI from January 2002 to June 2009 in the South Medical University, Zhujiang Hospital. These patients had a long-term disturbance of consciousness≥2weeks; GCS≤8 points; age more than 16 years old; without history of ear, brain injury, cardiopulmonary resuscitation, primary cerebral infarction. All of the patients' age, sex, cause, data of BAEP performance and awakening or not awakening are completely recorded.Examination and assessment standards in BAEP:Inspection time is from 2 week to 20 weeks after TBI, and all BAEP examination were taken before patients awakening. The outcome of awakening after the sixth month from injury was used as the criterion.Abnormal criterion of BAEP:①The peak latency(PL) of waveⅠ,Ⅲand V and the inter peak latency (IPL) of wave I-III and III-V beyond the normal group mean add three standard deviation (x+3 S).②The amplitude ratio of wave I and V more than two.Criterion of Awakening:We appraised the outcome of awakening in patients as following:At least one of the traits is apparent or easy to identify, and it must be repetitive or consistent:1) Simple commands can conducted.2) "Yes" or "No" with gesture or language can be replied. 3) Words can be understood. 4) Actions or emotional reactions in special environment are not caused by conditional reflection.Statistical methods:All data were analyzed by SPSS 13.0. Patients are divided into awakening group and coma group by sober or coma after the sixth month from injury. Independent sample t test was used when we find the indictors of prediction prognosis between two groups. P≤0.05 was considered statistically significant.Results The study found:22 patients had awaked in 63 patients at the sixth month(the probabilities of awakening in these patients are 34.9%). With abnormal index of BAEP indicators reaching 66.7%. Abnormal PL of waveⅠ,ⅢandⅤare 19.0%,27.0%,50.0%, abnormal IPL of waveⅠ-ⅢandⅢ-Ⅴare 19.0% and 39.7%, abnormal amplitude ratio of wave I and V are 11.1%.16 patients were sober at last in 21 patients with normal PL of wave I, III and V, IPL of wave I-III and III-V, and amplitude ratio of wave I and V in bilateral side (the probabilities of awakening were 76.2%); 8 patients having abnormal PL of wave V in bilateral side and7 having abnormal IPL of wave III-V in bilateral side were unconscious; 2 patients having disappeared wave V in unilateral side were unconscious. PL of wave V and IPL of wave III-V in bilateral side were significantly different between the conscious group and the unconscious group.(P<0.05). Other indictors aren't significantly different at least one side.Conclusions 1. BAEP findings can objectively evaluate partial cerebral function from the neurophysiological, can help to demonstrate the cerebral dysfunction and predict awakening of the TBI patients. 2. The patients difficult to become awakening who have abnormal PL of wave V, IPL of wave III-V in bilateral side, or wave V disappeared. Section twoEvaluation in prediction of outcome of awakening in unconscious patients after severe traumatic brain injury by new brainstem auditory evoked potential grading.Objective To analyze the manifestations of brainstem auditory evoked potential(BAEP) and explore the value of new BAEP grading in prediction of awakening in unconscious patients after severe traumatic brain injury(TBI).Methods The data were collected retrospectively in 93 patients suffering from severe TBI from January 2002 to June 2010 in the South Medical University, Zhujiang Hospital. These patients had a long-term disturbance of consciousness≥2weeks; GCS≤8 points; age more than 16 years old; without history of ear, brain injury, cardiopulmonary resuscitation, primary cerebral infarction. All of the patients' age, sex, cause, data of BAEP performance and awakening or not awakening are completely recorded.BAEP were classified according to indictors as following:peak latency(PL) of wave V, inter peak latency(IPL) of waveⅢ-Ⅴ, wave V disappear, BAEP were classified into three grades:Criterion of abnormal BAEP:The justification of abnormal BAEP was the same as above.New BAEP grading in the study:GradeⅠ:aLl BEAP findings were normal;Grade III:bilateral PL of wave Vor IPL of waveⅢ-Ⅴwere abnormal, unilateral or bilateral wave V were absent;Grade II:any abnormal BAEPs except GradeⅢ, including unilateral or bilateral peak latency (PL) of waveⅠ,Ⅲ, inter peak latency(IPL) of waveⅠ-Ⅲor amplitude ratio of wave I and V were abnormal, or unilateral PL of wave V or IPL of waveⅢ-Ⅴwere abnormal.Krieger grading standards:GradeⅠ:bilateral BAEP are normal;GradeⅡ:unilateral BAEP are abnormal;GradeⅢ:bilateral BAEP are abnormal.Criterion of Awakening: The justification of awakening after TBI was the same as above.All statistical analyses were made with SPSS 13.0. Kruskal-Wallis H Test was used to deal with the relationship between BAEP grading and outcome of awakening. We evaluated the correlation of BAEP grading with the probabilities of awakening using Spearman correlation test, P≤0.05 was considered statistically significant. Sensitivity equal to actual conscious patients in prognosis conscious patients divided by actual conscious patients, specificity equal to actual unconscious patients in prognosis unconscious patients divided by actual unconscious patients.Results 93 patients with severe traumatic brain injury in patients with long-term disturbance of consciousness (74 men,19 women), aged 16 years old to 70 years, mean 36.04 years. Patients'GCS was 3-8 when they were admission. From a total of 93 patients,11 cases were patients with high falling injury (3 cases recovery), 4 cases were Violence Contusion injuries (1 cases recovery),6 cases were falls (3 case recovery),71 cases were traffic accident (30 cases recovery),1 cases were knifed injury (the patient didn't recover). There are 37 patients became awakening in 93 patients (the probability of awakening are 39.8%). awakening time was 17-160 days (median is 65 days); there were 56 patients continuing coma or vegetative state at 6 months after injury,5 patients of them died during the observation period. There were different in three grades of new BAEP grading using Kruskal-Wallis H test (χ2=42.07, P＜0.001); the difference also exit between Krieger grading and awakening (x2=40.79, P＜0.001). There is a correlation between new BAEP grading and the probability of awakening in TBI patients when we used Spearman's correlation test (r=-0.662, P＜0.001); there is a correlation between Krieger grading and the probability of awakening (r=-0.617, P＜0.001). It is negative correlation between them, indicating that The higher the BAEP grades, the lower the probabilities of awakening is. Grade I was used indicator of easy sober, grade III was used indicators of poor sober. The sensitivity of new BAEP grading was 78.9%(30/38), specificity was 100%(15/15), the sensitivity of Krieger grading was also 78.9%(30/38), specificity was 89.2%(25/28).Conclusion 1. New BAEP grading standards can predict the patients' probability of awaking objectively and accurately at 6th month after injury.2. New BAEP grading standards showed grade I have 78.9% of patients awaking at 6th month; grade II probability of awaking dropped to 17.5%,15 patients who classified as grade III couldn't recover consciousness at 6th month.3. We set up our grading grade I as indicator of easy awake, grade III as indicator of not awake at 6th month after severe traumatic brain injury, the sensitivity was 78.9%(30/38), specificity was 100%(15/15) in our BAEP grading. Section three Evaluation of prognosis in long-term unconscious patients after severe traumatic brain injury by brainstem auditory evoked potential gradingObjective To investigate using the brainstem auditory evoked potential (BAEP) grading to evaluate the prognosis and awakening time in long term unconscious patients after severe traumatic brain injury.Methods The data were collected retrospectively in 93 patients suffering from severe TBI from January 2002 to June 2010 in the South Medical University, Zhujiang Hospital. The GOS score at the 6th month after the injury were recorded. Analysis the correlation between the BAEP classification and the awakening time, the patients'GOS score. The prognosis with GOS 5,4 classified as good prognosis, GOS 3,2,1 classified as poor prognosis.BAEP grading criterion:GradeⅠ: all BEAP findings were normal;GradeⅢ: bilateral PL of waveⅤor IPL of waveⅢ-Ⅴwere abnormal, unilateral or bilateral waveⅤwere absent.GradeⅡ: any abnormal BAEPs except GradeⅢ, including unilateral or bilateral peak latency (PL) of waveⅠ,Ⅲ, inter peak latency(IPL) of waveⅠ-Ⅲor amplitude ratio of waveⅠandⅤwere abnormal, or unilateral PL of waveⅤor IPL of waveⅢ-Ⅴwere abnormal.Glasgow outcome scale (GOS) criterion:1 point: death;2 point: Vegetative state:unconscious, with a heartbeat and breathing, sometimes eyes open, sucking, yawning and other local motor response;3 point: Severe disability: conscious, but the cognitive, speech and body movement are severely disabled, required others care in 24-hour;4 point: Moderate disability: cognitive, behavioral and personality disorders; with mild hemiplegia, ataxia, speech difficulties and other disabilities, are still capable of independent reluctantly in their daily life, family and social activities;5 point: Good recovery:able to re-enter normal social activities, and can return to work but may have all kinds of new sequels.Statistical methods:SPSS 13.0 statistical package used for statistical analysis. Kruskal-Wallis H test was used to analyze the correlation between the BAEP grading and the patients'GOS score..P≤0.05 was considered significant.Results 27 cases with good prognosis,66 patients with poor prognosis, total poor prognosis rate was 70.97%; 5 cases died, the total mortality rate was 5.38%.24 cases with good prognosis in gradeⅠ,14 patients with poor prognosis in grade I, poor prognosis rate was 36.84% in gradeⅠ; 3 cases with good prognosis in grade II, 37 patients with poor prognosis in gradeⅡ, poor prognosis rate was 92.50% in gradeⅡ; all of 15 patients were poor prognosis in the grade III, poor prognosis rate was 100%. The BAEP grading and GOS of 6 months after the injury status by Kruskal-Wallis H test,χ2=36.34, P＜0.001. There is statistically significant, that is to say, the higher the grade, the worse the prognosis of patients. If the grade I is used as the indicator of good prognosis, grade II is used as the indicator of poor prognosis, grade III is used as the indicator of very poor prognosis, the accuracy rate was 81.72%.Conclusions 1. The BAEP grading can reflect the degree of brain injury objectively and accurately; the higher the classification, the more serious brain damage is, the worse prognosis is.2. If the grade I is used as the indicator of good prognosis, grade II is used as the indicator of poor prognosis, grade III is used as the indicator of very poor prognosis, the accuracy rate was 81.72%. |
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