Kobe J. Med. Sci., Vol. 68, No. 1 , pp. E23-E29, 2022

Increase in the Number and Duration of Sleep Episodes During Class
After Reopening of Schools Following Closure due to COVID-19
SHIGEMI KIMURA1,2,*, YUTAKA TAKAOKA 2,3, and AKI SUGANO 2,4
1

Children’s Rehabilitation, Sleep & Development Medical Center, Hyogo Prefectural Rehabilitation Central
Hospital, Kobe, Japan;
2
Division of Medical Law and Ethics, Department of Medical Systems, Kobe University Graduate School of
Medicine, Kobe, Japan;
3
Data Science Center for Medicine and Hospital Management, Toyama University Hospital, Toyama, Japan;
4Center for Clinical Research, Toyama University Hospital, Toyama, Japan*Corresponding author
Received 30 August 2022/ Accepted 24 November 2022
Keywords: COVID-19 pandemic, School closure, Sleeping during class, Hypersomnolence disorders,
School-aged population
Sleep is important for the well-being of school-aged children. Almost all schools in Hyogo prefecture in
Japan were closed from April 7 to May 31, 2020, owing to the coronavirus disease 2019 pandemic. The
pandemic restrictions resulted in the disruption of the sleep routines of children. The number of children
who experienced sleepiness in class after school closure increased. The number of children who visited our
hospital 1 year before and after the closure was 208 (11.73 ± 3.24 years of age) and 155 (11.45 ± 3.30 years),
respectively. The number of chief complaints of sleep-related symptoms at the first visits showed nosignificant difference between the two time periods. The percentage of patients who slept during classincreased (but not significantly) after the school closure. However, the mean number and duration of sleep
episodes during class significantly increased from 0.31 ± 0.76 to 1.04 ± 1.14 episodes/day and from 15.8 ±38.6 to 45.7 ± 46.9 min/day (each P < 0.001) before and after school closure, respectively. The total numberof patients in our hospital with the primary central disorders of hypersomnolence, i.e., narcolepsy,
idiopathic hypersomnia, and Kleine–Levin syndrome, and the number of patients with insufficient sleep
syndrome after the school closure significantly increased compared with those before closure (P = 0.034
and 0.048, respectively). School closure was associated with an increased incidence of sleeping duringclass; therefore, maintaining a stable daily routine for children with sleep disorders could have an
alleviating effect.
The outbreak of coronavirus disease 2019 (COVID-19) has affected the lives of children and adolescentsworldwide. The Japanese government declared the first state of emergency in April 2020. Primary, junior high,and high schools, and universities in Hyogo prefecture, Japan, were closed from April 7 to May 31, 2020,
leading to a perceived increase in the number of patients who visited our hospital with complaints of sleepinessin class after school reopening. It was reported that the Japanese elementary and junior high school students whostayed up late at night during the school closure, experienced greater difficulty in getting up in the morning andslept longer than those students who returned to school [1]. It was also reported that the COVID-19 pandemic
resulted in significantly later bedtimes and longer internet use time after the school closure than before [2,3]. In
addition, more than half of the participants in the study had later wake-up, breakfast, and lunch times after theschool closure, which was associated with more unfavorable lifestyle changes and dietary intake [4]. Several
studies worldwide also reported lower sleep quality and poor mental well-being because of the restrictions
during lockdown [5,6]. However, to date, the impact of COVID-19 on children with sleep disorders has not been
well documented.
In circadian rhythm disorders, an individual’s internal sleep-wake rhythm and light-dark cycle aredesynchronized [7]. Individuals with circadian rhythm disorders cannot sleep or wake up naturally as required
for their work, school, or social obligations. In delayed sleep-wake phase disorder, a person remains asleep forseveral hours beyond the intended wake time, whereas advanced sleep-wake phase disorder shifts sleeping andwaking times several hours earlier than the desired or customary time. Other types of circadian rhythm disorders
include the following: irregular sleep-wake rhythm, wherein a person does not have a clear circadian rhythm;
non-24-h sleep-wake rhythm, wherein a person's natural circadian rhythm does not align with the 24-h day; andPhone: +81-078-927-2727

Fax: +81-078-925-9203

E-mail: 3658kimura1@gmail.com
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S. Kimura et al.
circadian rhythm sleep disorder not otherwise specified, which is a disorder that is difficult to categorize into anyof the aforementioned classifications [8].
Central disorders of hypersomnolence are characterized by severe daytime sleepiness despite normal quality
and timing of nocturnal sleep and can be classified into eight subtypes according to the International
Classification of Sleep Disorders, Third Edition (ICSD-3) [9]. This classification divides sleeping disorders into
two categories: primary forms, i.e., occurring on their own because of an abnormality of hypocretin-1 or the
immune system; and secondary forms, i.e., caused by an intimately related different condition. Primary forms,
such as narcolepsy types 1 and 2 [10], idiopathic hypersomnia [11], and Kleine–Levin syndrome [12] arediagnosed based on symptoms and sleep testing results, whereas, in secondary forms, hypersomnia is caused by
medical conditions, medication or substance use, psychiatric conditions, or insufficient sleep syndrome (ISS)[13].
Our study aimed to compare sleep pattern changes in school-aged children before and after school closure
during the COVID-19 pandemic.
MATERIALS AND METHODS
Participants
The study was approved by our institutional ethics committee (permit number 2104) and conformed to thetenets of the Declaration of Helsinki. Informed consent was obtained from the parents or legal guardians of allparticipants.
Our Children’s Rehabilitation, Sleep & Development Medical Center in Hyogo Prefectural Rehabilitation
Central Hospital has two divisions: rehabilitation and sleep disorders. Almost all disabled children are seen by apediatric orthopedic surgeon, and children with sleep disorders are seen by three pediatricians.
A total of 396 new patients visited the pediatric department of the hospital for treatment of sleep disorders
between April 7, 2019, and April 6, 2020, before the 54-day school closure during the COVID-19 pandemic, and261 new patients visited the department for the treatment of sleep disorders between June 1, 2020, and May 31,
2021, after the schools reopened. Preschool patients were excluded, and patients with diseases, such as cerebral
palsy and muscular dystrophy, and chromosomal abnormalities were also excluded. We investigated the sleep
patterns of school-aged children by collecting and comparing the chief complaints of 208 patients (boys, 112;
girls, 96; mean age, 11.73 ± 3.24 years) one year before the school closure to those of 155 patients (boys, 87;
girls, 68; mean age, 11.45 ± 3.30 years) one year after school reopening; the comparison of mean age between
the groups revealed no significant differences (P = 0.42) (Figure 1).

Figure 1. Data collection flow chart. The number of new patients depended on the number of available doctors qualified to
manage these cases (three before school closure, two after school closure).

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SLEEPING DURING CLASS AFTER COVID-19 PANDEMIC
Study design
The sleep-related chief complaints of patients who visited our hospital were retrospectively compared before
and after school closure due to the COVID-19 pandemic. Subsequently, we focused on the complaint that
underwent the largest change (indicated by the smallest P-value) and analyzed the sleep logs and diagnoses ofthe patients with this complaint.
Analysis of sleep-related symptoms
This analysis included data obtained from the interview forms in the medical records of the participants’ first
visit, during which families were asked to select the appropriate chief complaints of sleep-related symptoms,
namely, difficulty waking up, difficulty falling asleep, bad mood before sleeping, interrupted sleep, waking upvery early in the morning, unrefreshing sleep, snoring, difficulty sleeping owing to a stuffy nose, talking during
sleep, nightmares, night terrors, restless legs, itchiness during sleep, daytime drowsiness, sleeping during class,sleeping in the evening, absenteeism from school >2 days per week, and duration of use of electronic devices.
Analysis of sleep logs
The sleep logs were sent to the participants by mail before their first visit. The timing of sleep onset andawakening, total sleep duration, number and duration of episodes of awakening from sleep, and frequency andduration of sleeping during class were collected from the sleep logs. Sleeping during class was confirmed bysleep logs and information received from teachers and patients, according to the medical record. The daily means
and standard deviations were calculated based on the data from the week before visiting our hospital.
Test of central disorders of hypersomnolence
Polysomnography (PSG) and the multiple sleep latency test (MSLT) (Pro-Tech Body position sensors,
Phillips/Respironics Murrysville, PA, USA) were performed according to the standard protocols. Central
disorders of hypersomnolence were diagnosed using sleep logs, PSG, MSLT, and medical records according to
ICSD-3 [9]. Narcolepsy type 1 was diagnosed without measuring cerebrospinal fluid hypocretin-1 concentration
because the affected patients clearly showed cataplexy. The diagnosis of ISS was confirmed by a reduction insleeping during class and an extension of total sleep time to distinguish it from narcolepsy.
Statistical analysis
Statistical analyses were conducted using Microsoft Excel 2016 (Microsoft, Redmond, WA, USA). The
chi-squared test was used to compare the data in the medical records obtained at the first visit before school
closure with the corresponding values after school reopening for the number of sleep-related chief complaints,
absence from school for >2 days per week, and duration of daily use of electronic devices, and presence of ISS.
Paired Student’s t-test was used to compare normally distributed data (i.e., patients’ age before and after
school closure and total sleep duration). Nonparametric Mann–Whitney U test was used to compare
non-normally distributed data (i.e., time of sleep onset and offset, number of episodes and average duration of
awakenings from sleep, and number and average duration of sleeping during class). Differences in the incidence
rates of the total number of patients with narcolepsy types 1 and 2, idiopathic hypersomnia, and Kleine–Levinsyndrome between the 208 patients identified one year before school closure and 155 patients identified in theyear after reopening were analyzed using the two-sided Fisher's exact test using R software v4.1.3 (R Foundationfor Statistical Computing, Vienna, Austria) for a small number. Statistical significance was set at P < 0.05.
RESULTS
Changes in sleep-related symptoms and sleep logs
There were no significant differences in sleep disorder complaints, number of patients absent from school for>2 days per week, and duration of daily use of electronic devices before and after school closure (Table I).
According to the PSG results, no patient had obstructive or central sleep apnea. In terms of sleep-related chiefcomplaints, the smallest P-values (0.14) for the differences before and after school closure were obtained fornightmares and sleeping during class. The percentage of children with nightmares decreased from 12.5%(26/208) to 7.7% (12/155). The percentage of patients who slept during class was greater after reopening (31.6%,
49/155) than before closure (24.5%, 51/208). We decided to focus on sleeping during class because few children
had nightmares.

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S. Kimura et al.
Table I. Changes in sleep-related chief complaints, absenteeism from school, and duration of use of electronic devices by
patients before and after school closure during the COVID-19 pandemic

Boys/Girls (n)Age (mean ± SD, years)
Difficulty in falling asleep
Bad mood before sleeping
Interrupted sleep
Waking up very early in the morning
Difficulty in waking up
Unrefreshing sleep
SnoringDifficulty in sleeping owing to a stuffy nose
Talking during sleep
Nightmares
Night terrors
Restless legs
Itchiness during sleep
Daytime drowsiness
Sleeping during classSleeping in the evening
Absenteeism from school >2 days per week
Duration of using electronic devices(mean ± SD: h/day)

Beforen = 208
112/96
11.73 ± 3.24
120 (57.7)
15 (7.2)
73 (35.1)
21 (10.1)
155 (74.5)
57 (27.4)
29 (13.9)
11 (5.29)
26 (12.5)
26 (12.5)
13 (6.3)
22 (10.6)
18 (8.7)
75 (36.1)
51 (24.5)
37 (17.8)
92 (48.9)
n = 186
4.61 ± 3.84
n = 168Aftern = 155
87/68
11.45 ± 3.30
80 (51.6)
13 (8.4)
51 (32.9)
21 (13.5)
106 (68.4)
39 (25.2)
20 (12.9)
11 (7.1)
13 (8.4)
12 (7.7)
11 (7.1)
13 (8.4)
8 (5.2)48 (31.0)
49 (31.6)
33 (21.3)
66 (48.2)
n = 137
4.63 ± 4.03
n = 121

Ratio*
After/Before

P-value†

89.5
116.3
93.8
134.2
91.8
91.8
92.6
134.2
67.1
61.9
113.6
79.3
59.6
85.9
128.9
119.7
98.6

0.22
0.69
0.63
0.32
0.17
0.60
0.75
0.48
0.20
0.14
0.76
0.47
0.20
0.29
0.14
0.34
0.82

100.4

0.95‡

The before and after data are presented as frequencies (percentages).
SD, standard deviation; COVID-19, coronavirus disease 2019. “Electronic devices” include online gaming and watching
television and YouTube using smartphones and computers.
*
Ratio of the percentage after school closure to the percentage before school closure (expressed as a percentage).
†
Chi-squared test‡
Mann–Whitney U test

Changes in the sleep logs of patients who slept during class
The increase in the number of patients sleeping during class was the principal focus of this study. The
differences in the times of sleep onset and offset, mean total sleep duration, and mean number and duration of
awakenings from sleep before and after closure were not significant. However, the mean number of episodes andduration of sleeping during class before and after closure significantly increased from 0.31 ± 0.77 to 1.04 ± 1.14
episodes/day (P < 0.001) and from 15.8 ± 38.6 to 45.7 ± 46.9 min/day (P < 0.001), respectively (Table II).
Table II. Changes in sleep pattern at night and the time and duration of sleeping during class before and after school closurein patients who selected “sleeping during class” on interview forms before their first visit

Boys/Girls(n)Age (mean ± SD)
Sleep onset (time of day)Sleep offset (time of day)
TST (h)Interrupted sleep (n)Interrupted sleep (duration, min)Sleeping during class (n)Sleeping during class (duration, min)

Before school closure(n = 51, mean ± SD)
29/22
12.57 ± 2.07
23:38 ± 1:50
8:09 ± 1:51
8.57 ± 1.41
0.17 ± 0.74
9.1 ± 34.9
0.31 ± 0.77
15.8 ± 38.6

After school closure(n = 49, mean ± SD)
30/19
12.02 ± 2.68
23:33 ± 1:38
8:18 ± 1:54
8.56 ± 1.95
0.12 ± 0.37
4.30 ± 12.6
1.04 ± 1.14
45.7 ± 46.9

P-value*

0.65
0.70
0.96†
0.98
0.81
P < 0.001
P < 0.001

SD, standard deviation; TST, total sleep time (hours); Interrupted sleep (n), number of awakenings from sleep (episodes/day);Interrupted sleep (duration), average duration of awakenings from sleep (min/day); sleeping during class (n), number of sleep
episodes during class (episodes/day); sleeping during class (duration), average duration of sleeping during class (min/day)*Mann–Whitney U test
†Student’s t-test

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SLEEPING DURING CLASS AFTER COVID-19 PANDEMIC
Diagnosis of the patients who slept during class・Circadian rhythm disorders
The number of patients with delayed sleep-wake phase disorder, advanced sleep-wake phase disorder, anirregular sleep-wake rhythm, a non-24-h sleep-wake rhythm, and circadian rhythm sleep disorder, not otherwise
specified, were 29 (percentage of patients sleeping during class; 56.9%), 1 (2.0%), 3 (5.9%), 0, and 5 (9.8%),
respectively, before school closure, and 16 (32.7%), 0, 2 (4.1%), 0, and 2 (4.1%), respectively, after school
reopening. Their chief complaints included not only sleeping during class but also other sleep-related
complaints.
・Incidence of central disorders of hypersomnolence
The present study was conducted considering the possibility of an increase in the incidence of central
disorders of hypersomnolence. The number of cases of the primary forms, such as narcolepsy types 1 and 2,
idiopathic hypersomnia, and Kleine–Levin syndrome increased after school closure from 1 to 2, 2 to 4, 0 to 2,
and 0 to 1, respectively. Although there was no significant difference among the diseases owing to the small
sample size, the number of cases of these primary forms of sleep disorders in the total patient cohorts (208patients identified one year before school closure and 155 patients identified in the year after reopening)
increased significantly from 3 (1.4%) before school closure to 9 (5.8%) after school reopening (P = 0.034). The
chief complaint of all the patients with primary forms of central disorders of hypersomnolence was sleeping
during class. Importantly, the study participants had not been vaccinated against COVID-19 and had not had
COVID-19. Vaccination of teenagers had not started in Japan during the study period, and we confirmed thatnone of the participants had a history of COVID-19 based on a review of their medical records.
There was no patient with the secondary form of central disorders of hypersomnolence due to medical
conditions, medication or substance use, or psychiatric condition because none of the patients had anxiety ormood disorders.
The number of patients with ISS among patients who complained of sleeping during class increased from 10(19.6%) before school closure to 21 (42.9%) after school reopening. However, the number of patients with ISS
significantly increased from 28 (ratio to the total number: 13.5%) to 33 (21.3%) (P = 0.048). The chiefcomplaints of patients with ISS were not only sleeping during class but also daytime drowsiness.
DISCUSSION
Our results, obtained from the interview forms in the medical records of the participants’ first visit, indicatedno significant changes in sleep disorder complaints, number of patients absent from school for >2 days per week,or duration of daily use of electronic devices over the school closure period during the COVID-19 pandemic.
According to the results of the interview forms, the percentage of new patients who complained of sleeping
during class increased after the school closure, although this increase was not significant. Nakayama et al.
revealed that children stayed up significantly later at night and had more difficulty getting up in the morning
after the COVID-19 pandemic than before [2]. The participants in their study were students who did not visit thehospital. However, the participants in our study visited our hospital for therapy for sleep disorders. Hence, thedifferences in the results can be attributed to the difference in the type of participants. Furthermore, according to
the sleep log data, the mean number and duration of sleep episodes during class increased significantly in ourstudy.
The most common diagnosis among the patients who complained of sleeping during class was delayed
sleep-wake phase disorder. The sleep logs revealed that the sleep onset and offset times before school closure
were 23:38 ± 1:50 and 8:09 ± 1:51, respectively, and after school closure were 23:33 ± 1:38 and 8:18 ± 1:54,
respectively. Thus, the sleep cycles were consistent with the diagnosis. Patients with circadian rhythm disorders
may sleep during class [14].
The significant increase in the mean number of episodes and duration of sleeping during class after school
closure indicated a significant increase in the central disorders of hypersomnolence. Furthermore, the number ofpatients with primary forms of central disorders of hypersomnolence, such as narcolepsy types 1 and 2,
idiopathic hypersomnia, and Kleine–Levin syndrome, and the number of patients with ISS, significantly
increased compared with those before school closure. All patients with primary forms of central disorders ofhypersomnolence complained of sleeping during class in the interview form. In contrast, patients with ISS andcircadian rhythm disorders mentioned not only sleeping during class but also daytime drowsiness or difficulty inwaking up, which are characteristic of this disorder.
Additionally, the numbers of patients with primary forms of central disorders of hypersomnolence in 2015,2016, 2017, 2018, 2019, and 2020 in our hospital were 2 (total patients; n = 526), 1 (n = 596), 0 (n = 449), 2 (n =465), 3 (n = 369), and 9 (n = 261), respectively (unpublished data).

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S. Kimura et al.
The prevalence of narcolepsy with cataplexy has been reported as 0.025% to 0.05% [15]. Globally, its
prevalence is highest in Japan (0.16%) and lowest in Israel (0.0002%) [16]. Its age of onset in clinicalpopulations appears to be bimodal, with the first peak at 15 years and the second at 35 years [17]. Kleine–Levinsyndrome is a rare disorder with an estimated prevalence of 1–5/106 population when the ICSD-3 diagnostic
criteria are applied [18]. Hence, the primary forms of central disorders of hypersomnolence are rare diseases.
Further studies involving these disorders with larger sample sizes are needed.
A three-fold increase in narcolepsy onset was reported following the 2009 H1N1 winter influenza pandemicin China [19]. The autoimmune-mediated mechanism induced by influenza A virus H1N1 infection andvaccination was assumed to be a potential trigger for narcolepsy [20]. Alternatively, several environmental
factors have been investigated as risk factors for narcolepsy. These factors, such as eating habits, obesity,
migraines, and psychological stressors, could be the consequences rather than causes of narcolepsy [16].
The percentage of patients who reported daytime drowsiness decreased from 36.1% before school closure to
31.0% after school closure (after/before ratio, 85.9%). These results indicate that patients with narcolepsy types
1 and 2, idiopathic hypersomnia, Kleine–Levin syndrome, and ISS who originally complained of daytime
drowsiness started sleeping in class after school closure during the COVID-19 pandemic.
These results showed that the mean number and duration of sleep episodes during class and the number ofpatients with primary forms of central disorders of hypersomnolence and ISS significantly increased after school
closure during the COVID-19 pandemic. Further studies are needed on the central disorders of hypersomnolencewith larger sample sizes. Our study findings concluded that school closure during the COVID-19 pandemic wasassociated with an increase in the mean number and duration of sleep episodes during class after school
reopening.
ACKNOWLEDGEMENTS
We thank the staff at the Children's Rehabilitation, Sleep, and Development Medical Center, Hyogo
Prefectural Rehabilitation Central Hospital, especially Dr. Makiko Toyoura, who provided sound advice for thecare of the patients.
CONFLICT OF INTERESTS
The authors declare no conflicts of interest in association with the present study.

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REFERENCES
Saito M, Kikuchi Y, Lefor AK, Hoshina M. Mental health in Japanese children during school closures dueto the COVID-19. Pediatr Int. 2022;64(1):e14718.
Nakayama H, Matsuzaki T, Mihara S, Kitayuguchi T, Higuchi S. Change of Internet Use and Bedtime
among Junior High School Students after Long-Term School Closure Due to the Coronavirus Disease 2019
Pandemic. Children (Basel). 2021; 8(6):480. doi: 10.3390/children8060480.
Ueno C, Yamamoto S. The relationship between behavioral problems and screen time in children during
COVID-19 school closures in Japan. Scand J Child Adolesc Psychiatr Psychol. 2022;10:1-8.
Sugimoto M, Murakami K, Sasaki S. Temporal patterns of sleep and eating among children during school
closure in Japan due to COVID-19 pandemic: associations with lifestyle behaviours and dietary intake.
Public Health Nutr. 2022;16:1-15.
Illingworth G, Mansfield KL, Espie CA, Fazel M, Waite F. Sleep in the time of COVID-19: findings from17000 school-aged children and adolescents in the UK during the first national lockdown. Sleep Adv.
2022;3(1):zpab021.
Micheletti MB, Cafiero P, Nápoli S, Lejarraga C, Bradichansky PP, Vitale MP, et al. Sleep problems in asample of children with developmental disorders, before and during the COVID-19 pandemic. Arch Argent
Pediatr. 2021;119(5):296-303.
Sateia MJ. International classification of sleep disorders-third edition: highlights and modifications. Chest.
2014;146(5):1387-94.
Zhu L, Zee PC. Circadian rhythm sleep disorders. Neurol Clin. 2012;30(4):1167-91.
American Academy of Sleep Medicine International Classification of Sleep Disorders. Illinois: American
Academy of Sleep Medicine; 2014.
Nevsimalova S. Narcolepsy in childhood. Sleep Med Rev. 2009;13(2):169-80.
Trotti LM. Idiopathic hypersomnia. Sleep Med Clin. 2017;12(3):331-44.
Afolabi-Brown O, Mason TBA. Kleine–Levin syndrome. Paediatr Respir Rev. 2018;25:9-13.
Kohyama J, Anzai Y, Ono M, Kishino A, Tamanuki K, Takada K, et al. Insufficient sleep syndrome: an

SLEEPING DURING CLASS AFTER COVID-19 PANDEMIC
unrecognized but important clinical entity. Pediatr Int. 2018;60(4):372-5.
14. Kimura S, Takaoka Y, Toyoura M, Kohira S, Ohta M. Core body temperature changes in school-age
children with circadian rhythm sleep-wake disorder. Sleep Med. 2021;87:97-104.
15. Longstreth WT Jr, Koepsell TD, Ton TG, Hendrickson AF, van Belle G. The epidemiology of narcolepsy.
Sleep. 2007;30(1):13-26.
16. Dauvilliers Y, Arnulf I, Mignot E. Narcolepsy with cataplexy. Lancet. 2007;369(9560):499-511.
17. Dauvilliers Y, Montplaisir J, Molinari N, Carlander B, Ondze B, Besset A, et al. Age at onset of narcolepsy
in two large populations of patients in France and Quebec. Neurology. 2001;57(11):2029-33.
18. Gadoth N, Oksenberg A. Kleine-Levin syndrome; an update and mini-review. Brain Dev.
2017;39(8):665-71.
19. Han F, Lin L, Warby SC, Faraco J, Li J, Dong SX, et al. Narcolepsy onset is seasonal and increased following
the 2009 H1N1 pandemic in China. Ann Neurol. 2011;70(3):410-7.
20. Partinen M, Kornum BR, Plazzi G, Jennum P, Julkunen I, Vaarala O. Narcolepsy as an autoimmune disease:
the role of H1N1 infection and vaccination. Lancet Neurol. 2014;13(6):600-13.

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