BACKGROUND: It has proved that dynamic electroencephalogram (EEG) is definite in judging the outcome of ischemic hypoxic comatose patients, EEG is more sensitive to the cortical affection, but not sensitive to the subcortical and brainstem affections, thus it is necessary to clarify the indications of this technique in the clinical application.OBJECTIVE: To observe and compare the prognostic value of dynamic EEG and Glasgow coma score in comatose patients with different diseased region.DESIGN: A clinical case-controlled observation.SETTING: Union Hospital of Fujian Medical University.PARTICIPANTS: Sixty-eight comatose patients were selected from the Union Hospital affiliated to Fujian Medical University from June 1998 to January 2005. The diseased regions were identified using cranial CT (n =43) or MR (n =25). According to different primarily diseased regions, the comatose patients were divided into two groups: ① brainstem affection group (n =23): 13 males and 10 females, 14 - 62 years of age; ②diffuse cortical affection group (n =45): 28 males and 17 females, 23 - 75 years of age.METHODS: The dynamic EEG and Glasgow coma score were examined in the 45 comatose patients with primarily cortical affection and 22 comatose patients with primarily brainstem affection at acute phase. The patients were followed-up for 3 months to observe the outcome, The termination of outcome judgment was 3 months after attack or the death. The clinical outcome was classified as complete rehabilitation, survived with disability, death or vegetative state. Correlations of dynamic EEG and Glasgow coma score with the outcome of patients were analyzed. The correlations of dynamic EEG grades and Glasgow coma scores with the outcome were analyzed, and the prognostic value of dynamic EEG grades was compared between the two groups.MAIN OUTCOME MEASURES: ① Correlations of dynamic EEG and Glasgow coma score with the outcome of patients; ② Comparison of the prognostic value of dynamic EEG grades between the two groups.RESULTS: All the 68 patients were involved in the analysis of results. ① Correlations of dynamic EEG grades and Glasgow scores and their correlation analysis: EEG grades had significant negative correlation with Glasgow coma scores in both the cortical affection group and brainstem affection group (r = - 0.743,- 0.564, P ＜ 0.01, 0.05). In the cortical affection group, the Glasgow coma scores and dynamic EEG grades in the patients with the outcome of death or vegetative state were significantly different from those with the outcome of rehabilitation (P ＜ 0.05 - 0.01). In the brainstem affection group, the Glasgow coma scores were only significantly different between the patients with outcome of rehabilitation and death (P ＜ 0.05), and there was no significant difference in dynamic EEG grades among the three prognostic states (P ＞ 0.05). ②Comparison of the prognostic value of dynamic EEG grades between comatose patients with cortical affection and brainstem affection: The sensitivity, specificity and accuracy were all higher (P ＜ 0.05), while the error rate was lower (P＜0.05) in the cortical affection group than in the brainstem affection group.CONCLUSION: Dynamic EEG was valuable in predicting the outcome of comatose patients with primarily cortical affection, but it was not certainly valuable in those with primarily brainstem affection.