Association Between Apoe Polymorphism And Brain Function In Early Stage Of Aneurysmal Subarachnoid Hemorrhage

Objective To explore the association of APOE gene polymorphism with the brain function in the early stage of aneurysmal subarachnoid hemorrhage (SAH).Methods A total of 79 patients with aneurysmal SAH admitted in our hospital from March 2008 to May 2009 were recruited and their clinical data were collected. Electroencephalogram (EEG) was recorded on admission and in 3 to 5 d after onset to assess the change of brain function of the patients in acute stage of SAH. The result of the second EEG recording was defined as increasing degree of EEG abnormality if the decrease in alpha wave frequency, increase in slow wave or decline in amplitude were observed when compared with the first EEG recording. The APOE polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).Results Ten of 17 patients with APOEε4 (58.8%) showed the deteriorated EEG, which was significantly different from those without APOEε4 (18 of 62 patients, 29.0%, P = 0.023). However, neither the presence ofε2 norε3 was significantly different from those absent of it (P > 0.05). Univariate logistic regression analyses showed that both high Fisher grade (P = 0.028, OR = 2.917, 95% CI = 1.124 to 7.572) and APOEε4 (P = 0.027, OR = 3.492, 95% CI = 1.150 to 10.604) were risk factors to EEG aggravation after aneurysmal SAH. The association of APOEε4 for deteriorated EEG was more significant after adjustment for age, gender, Hunt-Hess grade on admission, and Fisher grade (P = 0.007, OR= 5.741, 95% CI = 1.625 to 20.280).Conclusion Our findings suggest that the APOEε4 allele is a risk factor to brain function aggravation in the early stage of aneurysmal SAH, and it may contribute to early brain injury after SAH.