Long-lasting EEG reactions in comatose patients after repetitive stimulation.
Twenty patients with severe head injury and a Glasgow Coma Scale of 4-6 were subjects of a multimodality EP study. After EEG recording during rest (control 1) 60 mechanical vibration stimuli and 60 visual stimuli (interstimulus interval 10 sec) were applied. Thereafter a second EEG (control 2) was measured. To quantify a long-lasting stimulated EEG alteration, control 2 was compared with control 1 on the basis of the spectral theta/beta ratio calculated from central derivations. In 50% of the patients the theta/beta ratio was changed in control 2 and therefore a long lasting stimulation effect can be assumed. Stimulus-induced cardiac alterations were also found.
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology; D001930:Brain Injuries / Q000503:physiopathology*; D003128:Coma / Q000503:physiopathology; D004569:Electroencephalography; D006801:Humans; D008875:Middle Aged; D010775:Photic Stimulation; D010812:Physical Stimulation; D014796:Visual Perception / Q000502:physiology