Electroencephalogram manifestations of a comatose patient with cerebral hemorrhage

ZHAO Yue; CHEN Peng; WANG Rui; XIE Li-na; LI Wei-na

doi:10.13798/j.issn.1009-153X.2025.01.014

Abstract：Following cerebral hemorrhage,some patients may enter a prolonged comatose state during which electroencephalography(EEG)plays a critical role in assessing the patient's condition.This case report involves a 53-year-old male with cerebral hemorrhage who presented with a Glasgow Coma Scale(GCS)score of 3.Head CT revealed hemorrhage in the left temporal lobe and left basal ganglia(approximately 93 ml),accompanied by brainstem compression,deformation of the left lateral ventricle,and rightward midline shift.After completing preoperative preparations,emergency surgeries including hematoma evacuation,decompressive craniectomy,and intracranial pressure probe implantation were performed.By postoperative day 50,the patient demonstrated improved consciousness with a GCS score of 11.A total of 24 EEG examinations were conducted during the perioperative period,each lasting between 6 minutes and 24 hours.The EEG findings are summarized as follows:①Initial coma phase(GCS 3),predominantly intermittent delta waves(0.5～1 Hz,70 μV)and complex waveforms across all leads,with no discernible alpha rhythm;②Transition phase(GCS 6),rhythmical activity at 7.5～7.9 Hz(40 μV)was observed in the O2 lead,accompanied by irregular theta waves(4～7 Hz,50 μV)in other leads,with no distinct alpha or delta rhythms;③Consciousness improvement phase(GCS 11),scattered alpha waves(8 Hz,30 μV)were detected in the C4 and O2 leads,along with low-to-medium amplitude beta and theta waves.These findings suggest that the emergence of intermittent rhythmical activity in the 7.5～8 Hz frequency band may serve as a positive indicator for impending consciousness recovery.Furthermore,this frequency band might represent an evolutionary precursor to the conventional 8～13 Hz alpha rhythm.