Prognostic value of standard EEG in traumatic and non-traumatic disorders of consciousness following coma

To investigate the prognostic value of standard electroencephalogram (EEG) in predicting the improvement of the level of consciousness in patients suffering from severe disturbances of consciousness following coma caused by acute brain injuries.

A standard EEG was recorded at admission in our rehabilitation department in a total of 46 patients with impaired consciousness states following coma (22 patients with traumatic brain injuries, 24 patients with non-traumatic brain injuries). We quantified the EEG abnormalities using the scale of Synek (1988) and correlated them with the basal level of cognitive functioning (LCF) scale score and with its variation after three months.

EEG scores correlated with LCF scores at admission (p<0.01) and with LCF scores' variation after three months (p<0.01) in patients with traumatic brain injury; EEG scores correlated only with LCF scores variation after three months (p<0.01) in patients with non-traumatic brain injury.

Standard EEG, analysed using the Synek scale, has a good prognostic value in both groups of patients with disorders of consciousness.

This work may have implications for clinical care, rehabilitative programs and medical-legal decisions in patients with impaired consciousness states following coma due to acute brain injuries.