In a patient with traumatic intracerebral lesions, we recorded two subsequent electroencephalograms with burst-suppression activity. Between the two measurements, the clinical condition of the patient deteriorated. The first EEG showed symmetrical interhemispheric asynchrony of bursts. In the second EEG, however, we noted synchrony from one hemisphere to the other, but asynchrony in the opposite direction. We propose a simple model that can explain why one-way asynchrony of burst-suppression activity is prognostically more severe than symmetrical asynchrony.