INTRODUCTION THE ABNORMAL REGULATION OF RAPID-EYE-MOVEMENT (REM) SLEEP IS A CENTRAL COMPONENT IN THE SYMPTOMA- TOLOGY OF NARCOLEPSY.1-3 The REM sleep often occurs at sleep

THE ABNORMAL REGULATION OF RAPID-EYE-MOVEMENT (REM) SLEEP IS A CENTRAL COMPONENT IN THE SYMPTOMATOLOGY OF NARCOLEPSY.1-3 The REM sleep often occurs at sleep onset, and many patients experience intrusive features of REM, such as muscle paralysis and hallucinations during wake-sleep transitions. Among the most striking behavior symptoms of narcolepsy is the triggering of the muscle paralysis of REM during otherwise alert and aroused waking (cataplexy).1-3 This atypical expression of REM features is thought to result from genetically mediated abnormalities in hypothalamic, brain stem, and basal forebrain function.1,2,4 Cataplexy represents the clearest indication that emotional processes are involved in the REM abnormalities of narcolepsy. Emotion is a potent trigger of cataplexy in most patients, with positive emotions such as joy/elation, excitement, and surprise being particularly likely to elicit cataplectic attacks.5,6 Animal studies have indicated that when cataplexy is induced by positive (or reward) emotions, cholinergic and dopaminergic activity in regions of the basal forebrain and extended amygdala, which normally participate in the regulation of positive emotion,7-12 are dramatically altered.2,13,14 Whereas positive emotion can trigger cataplexy in narcolepsy, negative emotion appears to be increased during sleep. Increased negative emotion is seen particularly when REM-like hallucinations or muscle paralysis appear at wake-sleep transitions,1,15-21 and have been reported also for nocturnal sleep.15 As with positive emotion, this increase in negative emotion is likely to be paralleled by abnormalities in neural processes that modulate these emotions. The function of noradrenaline and serotonin, which are implicated in the regulation of anxiety, fear, and depression,22-24 are altered at several levels of the neuraxis in narcolepsy.25,26 Tricyclic antidepressants, which inhibit the reuptake of norepinephrine and serotonin and are potent REM inhibitors, reduce the occurrence of hypnagogic hallucinations and sleep paralysis and diminish the sleep-associated negative emotion in narcoleptic patients.1 Changes in negative emotion within the REM sleep of narcoleptic patients would be predicted based on the monoaminergic-cholinergic imbalance of this disorder. Not much is known about changes in emotion within the REM sleep of patients with narcolepsy, although feelings of anxiety and fear have been reported more frequently than in REM reports from normal subjects.15 To investigate emotion in narcoleptic REM, 15 patients with narcolepsy and 9 healthy control subjects were asked to rate their dream emotions upon being instrumentally awakened from this stage (for details of emotions in the normal group, see Miller et al26). All subjects slept in their own homes and were monitored with ambulatory polysomnography by one of the authors (RF). Since the pathophysiology of narcolepsy might alter not only emotion, but also the stability of REM, the latter was measured and related to emotion. Results are discussed with reference to the altered neurobiology and the general alterations in REM mentation in narcoleptic patients. Other findings from the present study, and associated methodologic and neurocognitive issues, have been presented and discussed elsewhere.27-30