Relationship between Kleine-Levin syndrome and upper respiratory infection in Taiwan.
OBJECTIVE
In Kleine-Levin Syndrome (KLS), new episodes of hypersomnia are often preceded by an acute flu-like syndrome or upper airway infection 3 to 5 days before onset. This study investigated the relationship between the occurrence of mild upper respiratory tract infections (URIs) in the general population and the occurrence and seasonality and hypersomnic episodes in KLS patients.


METHODS
This investigation was a longitudinal clinical study. Based on data obtained from the National Health Research Institutes between 2006 and 2007, the timing of hypersomnic episodes in 30 KLS patients were compared with calendar reports of URI events, and the results compared with age-matched general Taiwanese population.


METHODS
Clinical symptoms, physical examination, polysomnographic recording, SPECT study, and laboratory tests affirming KLS during both periods of hypersomnic attack and non-attack were collected. Every symptomatic episode was then followed up. The cross-correlation function (CCF) and bivariate correlations analysis were performed to see the relationship between KLS and URIs.


RESULTS
A positive finding of CCF analysis and significant bivariate correlations were found between KLS episodes and URI in the general population (r = 0.456*). In onset of hypersomnia, significant correlations existed among "acute upper respiratory infections" (r = 0.446*), "acute bronchitis and bronchiolitis" (r = 0.462*), and "pharyngitis and nasopharyngitis" (r = 0.548*) subtypes of infections. A positive correlation between higher reports of symptomatic hypersomnia and URI also existed in a given season. A positive nonsignificant trend for "allergic rhinitis" (r = 0.400) was also found.


CONCLUSIONS
The agent behind URI or its consequence (such as fever) is associated with increased incidence of KLS episodes and may explain periodic symptomatic recurrences.
Sleep Center and Child Psychiatry Department, Chang Gung Memorial Hospital and University, Linkou, Taiwan.
Yu-Shu
YS
Huang
Christian
C
Guilleminault
Kuang-Lin
KL
Lin
Fang-Ming
FM
Hwang
Feng-Yuan
FY
Liu
Yen-Ping
YP
Kung
D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D017593:Kleine-Levin Syndrome / Q000453:epidemiology / Q000209:etiology*; D008137:Longitudinal Studies; D008297:Male; D017286:Polysomnography; D012141:Respiratory Tract Infections / Q000150:complications* / Q000453:epidemiology; D013624:Taiwan / Q000453:epidemiology; D015899:Tomography, Emission-Computed, Single-Photon; D055815:Young Adult