Sympathetic and cardiovascular activity during cataplexy in narcolepsy.

• 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.

Keyword

Blood Pressure

physiology

Cataplexy

physiopathology

Electrocardiography

Electroencephalography

Electromyography

Electrooculography

Heart Rate

physiology

Humans

Intracellular Signaling Peptides and Proteins

deficiency

Male

Narcolepsy

metabolism

physiopathology

Neuropeptides

deficiency

Sympathetic Nervous System

physiopathology

Young Adult

Publication and Content Type

ref (subject category)

art (subject category)