Analysis Of Coma Patients With Cerebral Evoked Potentials And Blink Reflex And Its Prognostic Evaluation

Objective:To analyze the cerebral evoked potentials and blink reflex characteris-tics of coma patients, and combined with glasgow coma score (GCS) to approach its prognostic value in patients with coma.Methods:40comatose who hospitalized in ICU ward and score3-12of GCS were examined by brainstem auditory evoked potential (BAEP)、somatosensory evoked potential(SEP) and blink reflex(BR) in24hours after coma.At the same time,the GCS、clinical assessment of brainstem reflex was performed, to observe patients’prognosis after a month.BAEP, SEP graded by Cant grading standard, BR grouped according to the test results,the prognosis were divided into improved、 persistent coma state,death.A portion of the objects were examined in24hours after coma,at one week and one month respectively, to observe alteration of these index, and they were graded into4groups according to the alteration:Group A:at least one index improved while other changeless; Group B:all the index changeless; Group C:at least one index to get worse while other changeless; Group D:some improved and others to get worse.Results:Of the40cases,23patients died,13cases in persistent coma state,4cases improved.1.Relationship between BAEP, SEP, BR, GCS and prognosis:Of BAEP,11cases were normal (gradeⅠ),while14were abnormal (grade Ⅱ) who manifested as extension of the latency and the interpotential interval, reduce of the amplitude, Ⅴ/Ⅰ amplitude ratio<1/2,waveform discrete,et al.15patients failed to draw reliable V unilaterally or bilaterally (grade).Grade Ⅰ, Ⅱ relatively got an good prognosis,mortality in36%, grade Ⅲ got a poor prognosis, the mortality rate is93%. Prognostic differences between BAEP groups have statistical significance (P<0.05).During the acute phase of coma,abnormal rate of SEP was high (85%),only6patients were normal(grade Ⅰ),while22patients with cortical potentials disappeared (grade Ⅲ),12cases were abnormal (grade Ⅱ)who showed cortical potentials latency prolongation,wave amplitude of N20was severely reduced, waveform discrete,et al.Compared to grade Ⅲ,grade Ⅰ、Ⅱ got a better prognosis.Prognostic differences between SEP groups have statistical significance (P<0.05).BR were abnormal in all the40patients.Of the total,30cases had no reaction even in strong stimulation,while9cases draw R1bilaterally,1case draw R1unilaterally.All reactions showed prolongation of latency and/or low amplitude response.BR of all patients were not elicited R2and/or R2’. According to the test results of BR,40patients fractionated to two groups:no response and have response.Prognostic differences between BR groups don’t have statistical significance (χ2=1.989, P=0.370).GCS score of all patients in the range of3-11,of the26cases who scored3,20cases died,mortality scored77%;Of the14cases who scored4-11,3cases died,mortality was21%.The prognosis differences of the coma patients with different degrees has statistics significance(P<0.05).2.Spearman correlation analysis between BAEP、SEP、BR and GCS:BAEP、 BR and GCS have no statistical correlation(P>0.05), while SEP and GCS were positively correlated (rs=0.633, P<0.01).3.Dynamic detection:15cases were tooken dynamic detection.5cases in group A, BAEP、SEP at least one got better, including3cases of BR got better, they did not elicit any waveform or only elicit R1with reduced amplitude in24h after coma, but improved significantly when retested, the performance of the Rl waveform clearer than the former, even can elicit R2,5cases were all under persistent coma state.2cases in group B,one patient improved while the other one under persistent coma state;8cases in group C,BAEP、SEP at least one got worsen,7cases of BR failed to draw certain waveform;a case was still elicited R1bilaterally with reduced amplitude and normal latency.Prognostic differences between dynamic detection groups has statistical significance (P<0.05).Results has no change while the BR removed from this analysis.Conclusions:BAEP、SEP and GCS can predict the prognosis of coma patients effectively at certain extent,BR in the acute state of coma were abnormal in different degrees,can not predict the prognosis accurately.