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Autonomic nervous system activity changes have been described during cataplexy as playing a role in triggering it. To confirm these previous findings, we investigated the time course of sympathetic and cardiovascular activities during cataplexy. We made for the first time microneurographic recordings of 10 cataplectic episodes in three patients with hypocretin-deficient narcolepsy. During microneurography, muscle sympathetic nerve activity (MSNA) was recorded simultaneously with heart rate (HR), respiratory movements, arterial finger blood pressure (BP), electroencephalography, electro-oculogram and superficial electromyogram. Results showed no significant autonomic changes before the onset of the cataplectic episodes. Cataplexy was associated with a significant increase in MSNA and BP compared with baseline, whereas HR was markedly decreased. An irregular breathing pattern mainly characterized by apnea typically occurred during the attacks. In conclusion, our findings did not show significant changes in autonomic activity prior to cataplexy onset, ruling out a triggering role of the autonomic system. However, cataplexy was associated with co-activation of sympathetic and parasympathetic autonomic systems, a pattern reminiscent of that reported during the vigilance reaction in animals.

Objectives The purpose of our study was to describe the behavioral aspects and quality of life of childhood narcolepsy with cataplexy (NC). Methods We performed a case-control study based on self-administered questionnaires in 30 NC hypocretin-deficient patients, 39 epilepsy patients, and 39 healthy controls matched for sex and age. Results Our population of children and adolescents with NC showed an increase in internalizing problems in line with previous reports, typically represented by withdrawal and depression symptoms, and somatic complaints. The two patients groups share higher scores than controls for anxiety disorders, attention, social and oppositional-defiant problems. Psychopathological profile in NC were found to be positively correlated with early NC onset, diagnostic delay, nocturnal disturbed sleep, shorter sleep latency and greater number of Sleep Onset REM Periods at Multiple Sleep Latency Test. On the other hand, treatment and disease duration, positively influenced the behavioral evolution. The psychosocial health of pediatric NC also turned out to be worse than in healthy controls, while the physical health showed no significant differences. Conclusions We found a specific psychopatological profile in a large pediatric NC sample, compared with another neurological chronic disease (epilepsy) and healthy controls. Symptoms of withdrawal, depression and somatic complaints, were specific of NC, and not observed in the two other groups. Effective treatment, and self-awareness of the disease should be promoted in NC children for the positive impact on behaviour and psychosocial health.

To evaluate the amplitude of submentalis muscle EMG activity during sleep in patients with narcolepsy/cataplexy with or without REM sleep behavior disorder (RBD).Observational study with consecutive recruitment.Sleep laboratory.Thirty-four patients with narcolepsy/cataplexy and 35 age-matched normal controls.Half the patients (17 subjects) had a clinical and video polysomnographic diagnosis of RBD. The average amplitude of the rectified submentalis muscle EMG signal was used to assess muscle atonia, and the new REM sleep Atonia Index was computed. Chin muscle activations were detected and their duration and interval analyzed. REM sleep Atonia Index was lower in both patient groups (with narcolepsy patients with RBD showing the lowest values) with respect to controls, and it did not correlate with age as it did in controls. The total number of chin EMG activations was significantly higher in both patient groups than controls. No significant differences were found between the two groups of patients, although more chin EMG activations were noted in narcolepsy patients with RBD than those without.Elevated muscle activity during REM sleep is the only polysomnographic marker of RBD. This study shows that polysomnographically evident RBD is present in many patients with narcolepsy/ cataplexy. This condition might be specific to narcolepsy/cataplexy, reflecting a peculiar form of REM sleep related motor dyscontrol (i.e., status dissociatus), paving the way to enacting dream behaviors, and correlated with the specific neurochemical and neuropathological substrate of narcolepsy/cataplexy.