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.
Donadio
Vincenzo
V
Department of Neurological Sciences, University of Bologna, Bologna, Italy. vincenzo.donadio@unibo.it
Plazzi
Giuseppe
G
Vandi
Stefano
S
Franceschini
Christian
C
Karlsson
Tomas
T
Montagna
Pasquale
P
Vetrugno
Roberto
R
Bugiardini
Enrico
E
Mignot
Emmanuel
E
Liguori
Rocco
R
D001794:Blood Pressure / Q000502:physiology*; D002385:Cataplexy / Q000503:physiopathology*; D004562:Electrocardiography; D004569:Electroencephalography; D004576:Electromyography; D004585:Electrooculography; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000172:deficiency; D008297:Male; D009290:Narcolepsy / Q000378:metabolism / Q000503:physiopathology; D009479:Neuropeptides / Q000172:deficiency; D000068797:Orexins; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D055815:Young Adult
D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins