| ObjectiveTo Investigate the risk factors of acute bilirubin encephalopathy, diagnostic value and clinical significance for MRI and BAEP for ABE to provide an objective basis for diagnosis and prognosis of ABE.Material and MethodsThe research includes data bases of clinic for 114 patients of hyperbilirubinemia whose TSB level of the hour were in 95% of high-risk areas. According to the clinical manifestations of ABE and (Bilirubin-induced neurological dysfunction) BIND score we divided the them into two groups. There were 77 patients with ABE (30 of slightly ABE,19 of moderate ABE and 28 of severe ABE), while 37 without ABE. They all received MRI sanning in a magnetic field with the strength of 1.5-3.0 Tesla at ages of 8±3.8(1-26) days of life.Scanning sequence were T1WI, T2WI and DWI. Routine T1WI had three kinds of sequences (SE,IR and FFE). In 56 patients symmetric hyperintense globus pallidus was shown on T1WI at the first MRI. BAEP examination were taken with the equipment (the United States Nicolet Vikaing IV electromyogram evoked potential), and places the electrodes according to the international 10-20 system in 25℃and quiet room. There were 93 patients received the examination of brain stem auditory evoked potential at ages of 11±5.4 (3-31) days of life.ResultsComparing the two groups with and without ABE, gestational age [(38.4±1.6) and (39.0±1.5), t= 2.137 P= 0.036] and birth weight [(3220±603) and (3446±476), t= 2.168 P= 0.033] of ABE group were samaller than that of non-ABE group, the level of TSB[(545.3±188.9) and (438.3±113.4), t= 3.174 P= 0.002], B/A[(1.0±0.35) and (0.85±0.24), t= 2.257 P= 0.026], and IBIL[(494.7±187) and (414±102), t= 2.445 P= 0.016] for ABE were significantly higher than no-ABE group; Using TSB, B/A and IBIL as tools for the diagnosis of ABE and according to ROC curve analysis,we found ROC of area under curve of TSB, B/A, and IBIL were> 0.5 and when the TSB= 486umol/L, B/A= 0.945, and IBIL= 478umol/L, the sensitivity and specificity for diagnosising ABE were the highest (0.622 and 0.743,0.5 and 0.851,0.514 and 0.8). For the two groups of GP(+) and GP(-), the level of TSB,B/A and IBIL existed statistically significant.There were 5 cases had T2WI GP(+) whose TSB values were 377.3 umol/L,487.3 umol/L,735.1 umol/L,639.7 umol/L,707.6 umol/L; The diagnostic test of T1WI GP(+) for ABE were:1. Accuracy= 69%; 2. Sensitivity= 64.9%; 3. Specificity= 77.7%; 4. The positive predictive value (PV+)= 85.7%; 5. negative predictive value (PV-)= 51.9%; 6. positive likelihood ratio (LR+)= 2.9; 7. negative likelihood ratio (LR-)= 0.45; 8.AUC= 0.713; P= 0.000; 95% IC= (0.611-0.815); The diagnostic test of T1WI GP(+) with clear boundary for ABE were:: 1. Accuracy rate= 66.4%; 2. Sensitivity rate= 54%; 3. Specific rate= 91.7%; 4.PV+= 93%; 5.PV= 49.3%; MRI T1WI GP(+) for diagnosising mild ABE, moderateABE and severe ABE were statistically significant (P=0.027;0.003;0.000); 93 patients were received BAEP examination, and only 9 patients had the completely normal BAEP. The abnormal rate were 90%. V waves instead of the severity of BAEP and the 93 patients accounted 34 (40.5%) of mild abnormalities,21 (25%) of moderate abnormalities and 29 (34.5%) severe abnormalities. We divide the patients into four groups according to the level of TSB(TSB<342umol/L is 1 group,342umol/L≤TSB<428umol/L is 2 group,428umol/L≤TSB<513umol/L is 3 group and TSB≥513umol/L is 4 group).We compared the patients of 1 group, respectively with 2,3,4 group and found the abnormal rate of BAEP is different (X2= 7.078,6.791,9.232, P= 0.029,0.034,0.001), then for the 2,3,4 group,there are no significant difference. Severe changes (≥80dnlBL) of V wave response was of impotance for diagnosising ABE (X2= 8.88, P= 0.003).ConclusionThe incidence of acute bilirubin encephalopathy are related with gestation age, birth weight, TSB, B/A and the pathological state (such as infection). When the reason for hyperbilirubinemia is hemolysis,specially Rh hemolytic, infection and intracranial hemorrhage, we should take active measures. MRI T1WI GP(+) is the characteristic of ABE, not only hyperintense but also clear boundary for GP(+) can improve higher specificity of the diagnosis for ABE. The GP(+) number of cases for MRI T1WI increases as the severity of ABE advancing and the relationship between them are more closely. If MRI T2WI GP(+) occurs in ABE, the prognosis is poor; MRI T2WI GP(+) combined with clinical manifestations in infancy subsequently are the diagnosis of chronic bilirubin encephalopathy. Brain Stem Auditory Evoked Potentials is a sensitive indicator for diagnosising ABE.When the level of TSB>342umol/L,the majority cases of BAEP were abnomal, but most of them have reversible changes, for the severe changes(V wave response areas>80dBnHL) may indicate poor prognosis. |
