Circadian Rest-Activity Rhythm in Pediatric Type 1 Narcolepsy.
OBJECTIVE
Pediatric type 1 narcolepsy is often challenging to diagnose and remains largely undiagnosed. Excessive daytime sleepiness, disrupted nocturnal sleep, and a peculiar phenotype of cataplexy are the prominent features. The knowledge available about the regulation of circadian rhythms in affected children is scarce. This study compared circadian rest-activity rhythm and actigraphic estimated sleep measures of children with type 1 narcolepsy versus healthy controls.


METHODS
Twenty-two drug-naïve type 1 narcolepsy children and 21 age- and sex- matched controls were monitored for seven days during the school week by actigraphy. Circadian activity rhythms were analyzed through functional linear modeling; nocturnal and diurnal sleep measures were estimated from activity using a validated algorithm.


RESULTS
Children with type 1 narcolepsy presented an altered rest-activity rhythm characterized by enhanced motor activity throughout the night and blunted activity in the first afternoon. No difference was found between children with type 1 narcolepsy and controls in the timing of the circadian phase. Actigraphic sleep measures showed good discriminant capabilities in assessing type 1 narcolepsy nycthemeral disruption.


CONCLUSIONS
Actigraphy reliably renders the nycthemeral disruption typical of narcolepsy type 1 in drug-naïve children with recent disease onset, indicating the sensibility of actigraphic assessment in the diagnostic work-up of childhood narcolepsy type 1.
Department of Psychology, University of Bologna, Bologna, Italy.
Marco
M
Filardi
DIBINEM - Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.|IRCCS - Istituto delle Scienze Neurologiche, AUSL di Bologna, Italy.
Fabio
F
Pizza
Department of Developmental and Social Psychology, Sapienza University, Rome, Italy.
Oliviero
O
Bruni
Department of Psychology, University of Bologna, Bologna, Italy.
Vincenzo
V
Natale
DIBINEM - Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.|IRCCS - Istituto delle Scienze Neurologiche, AUSL di Bologna, Italy.
Giuseppe
G
Plazzi
D056044:Actigraphy; D000293:Adolescent; D000465:Algorithms; D002385:Cataplexy / Q000503:physiopathology; D002648:Child; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009290:Narcolepsy / Q000503:physiopathology*; D012146:Rest / Q000502:physiology*; D012574:Schools; D012890:Sleep / Q000502:physiology*; D013334:Students
actigraphy; circadian rhythms; motor activity; narcolepsy; pediatrics