The Influence Of Apoe On The Electrical Activity Of Brain In Acute Phase After Mild/moderate Traumatic Brain Injury

Objective To investigate the influence of apolipoprotein E gene (APOE) on the electrical activity of brain at the acute stage of mild/moderate traumatic brain injury.Methods(1)The clinical data of 118 patients with mild/moderate traumatic brain injury and 40 normal subjects for control were collected. The APOE genotyping of every subject was performed by means of PCR-RFLP.(2)The electrical activity of brain in every patient was recorded by electroencephalogram 1 ~ 3d and 5 ~ 7d after traumatic brain injury respectively. All the subjects for control were examined by electroencephalogram under being conscious, calm, eyes closed and normoglycemic condition.(3)The electroencephalograms of every patient were assessed in a qualitative way, and quantitative data of every electroencephalogram were collected.(4)χ2 test, analysis of variance and logistic regression analyses via SPSS version 11.5 were performed to analyze the relationship among APOE genotypes, electroencephalogram data and clinical data.Results(1) The quantitative data of electroencephalograms among APOEε2, APOEε3 and APOEε4 carriers of normal subjects had no statistic difference (P=0.097). In 118 patients with mild/moderate traumatic brain injury, the quantitative data among APOEε2, APOEε3 and APOEε4 carriers had significant difference (P=0.008). Compared with APOEε3 carriers, the energy value of slow waves was more in patients with APOEε4 and less in patients with APOEε2.(2) In order to diminish the influence of hematoma on electronic activity of brain, 6 traumatic brain injury patients with increase of hematoma volume or delayed hematoma were excluded when the results of electroencephalograms within a week after trauma were compared further, and 112 patients were enrolled. 12 out of 22 patients with APOEε4 (54.5%) presented with deteriorated electroencephalogram, which was significantly higher than that of patients without APOEε4(16 of 90 patients, 17.8%, P=0.000). Comparison of the first and second electroencephalograms demonstrated that the slow waves in cases with APOEε2 and APOEε3 decreased(P<0.05), and the reduction of slow waves in APOEε2 carriers was more obvious than APOEε3 carriers (P=0.025). However, the slow waves in patients with APOEε4 significantly increased(P=0.010), Logistic regression analyses showed that APOEε4 was a risk factor to electroencephalogram aggravation after traumatic brain injury.Conclusion(1) In normal adults, the electrical activity of brain is not significantly different among the three APOE groups. However, under the provocation of traumatic brain injury, the influence of APOE on the electrical activity of brain presents hypospecific.(2) APOEε4 is bad for the electrical activity of brain and APOEε4 is a risk factor to electroencephalogram aggravation during acute stage after mild/moderate traumatic brain injury. However, APOEε2 seems beneficial for the recovery of electrical activity of brain.