DISTURBANCES OF THE RAPID EYE-MOVEMENTS (REMS) OF REM-SLEEP IN PATIENTS WITH UNILATERAL ATTENTIONAL NEGLECT - CLUE FOR THE UNDERSTANDING OFTHE FUNCTIONAL MEANING OF REMS

Horizontal saccades during wakefulness and horizontal rapid eye moveme nts (REMs) during REM sleep were recorded in 6 unilateral brain damage d patients suffering from attentional neglect and 6 unilateral brain d amaged control patients. During REM sleep, patients with neglect showe d a nearly total suppression of REMs directed away from the side of th e lesion; controls had a significantly milder frequency reduction of t he same movements. In all patients the frequency reduction of REMs con tralateral to the lesion equally affected isolated REMs (i.e., REMs pr eceded by intervals of oculomotor quiescence longer than 2 sec) and RE M bursts (i.e., REMs preceded by intervals shorter than 2 sec). During voluntary inspection in waking, saccades directed ipsilaterally and c ontralaterally to the lesion were present in both groups of patients, although patients with neglect confined their inspection to the hemisp ace ipsilateral to the lesion. Results are discussed in terms of their implications for the understanding of the neurophysiological basis of REM sleep oculomotor activity and dream production, as well as for th e neurophysiopathological basis of the neglect syndrome. It is propose d that REMs are functionally equivalent to waking reflex orienting sac cades generated by a neural network including the relevant modulatory action of the parietal lobes and the superior colliculi.