Chapter 23. Studies on sleep during the apallic syndrome

The presence of electroencephalographic and behavioral patterns typical of sleep in unconscious patients was established some time ago (Jouvet et al., 1961; Chatrian et al., 1963; Silverman, 1963; Hess, 1965; Bergamasco et al., 1966a, b; Bricolo, 1966; Cadilhac et al., 1966; Lepetit et al., 1966). There have also been studies on the correlation between the organization of sleep, degree of coma, and anatomic cerebral lesions (French, 1952; Jouvet et al., 1961; Silverman, 1963; Bricolo, 1966; Cadilhac et al., 1966; Lepetit et al., 1966). Finally, it has been suggested that the type of sleep organization might yield useful elements for a prognosis (Bergamasco et al., 1966a, b; Bricolo, 1966). The research carried out by Dolce and Kaemmerer (1966), Gentilomo et al. (1966), Bricolo (1966), Rosadini and Gentilomo (1967) appears particularly important, since they studied the EEG patterns of sleep in a group of comatose patients who were evolving towards the apallic syndrome. These authors reported that they had found all the various phases of physiologic sleep, noticing only a peculiar gradual recovery of each single phase, characterized by the constant delay of desynchronized sleep with REM which always reappears after the complete restructuring of synchronized sleep. These initial observations led to further research on the sleep of comatose patients and in particular in cases of prolonged comas and of apallic syndromes. These studies were undertaken during the past few years by sleep laboratories in Turin, Frankfurt, Genoa, and Verona.