Fig. 2.

AC pattern in patient 4. A: the rhythm shows clear spindling while she is resting; B: spontaneous biting on tube after an increased respiratory effort (arrow), following which the AC pattern appears less modulated and with slightly increased voltage. Noxious stimulation had identical effect. The movement artefacts in the O2 and O1 leads reflect increased respiratory efforts. Common average derivation, using limited montage as in Fig. 1. AC: alpha coma.