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Hypocretin and human African trypanosomiasis
Yves Dauvilliers1, Sylvie Bisser, Florian Chapotot
1Department of Neurology, University Hospital Gui de Chauliac, INSERM U888, Reference Centre for Narcolepsy, Montpellier France. y-dauvilliers@chu-montpellier.fr
Sleep
|March 28, 2008
Summary
This study investigated hypocretin-1 levels in human African trypanosomiasis (HAT), finding they were higher than in narcolepsy but lower than controls. Hypocretin system dysfunction may contribute to sleep disturbances in HAT.
Area of Science:
- Neurology
- Sleep Medicine
- Parasitology
Background:
- Human African trypanosomiasis (HAT), caused by Trypanosoma brucei gambiense (Tb.g.), is a parasitic disease affecting the central nervous system.
- Sleep disturbances, including excessive daytime sleepiness, are common in advanced stages of HAT.
- The hypocretin (orexin) system is crucial for regulating sleep-wake cycles, and its dysfunction is implicated in narcolepsy.
Purpose of the Study:
- To characterize clinical and polysomnographic features of Tb.g. HAT patients across different disease stages.
- To measure and compare cerebrospinal fluid (CSF) hypocretin-1 levels in HAT patients, narcoleptic patients, and neurologic controls.
- To explore the association between CSF hypocretin-1 levels and sleep disturbances in HAT.
Main Methods:
- Twenty-five untreated Tb.g. HAT patients were clinically evaluated and interviewed about sleep complaints.
- Disease staging (I, II, intermediate) was determined by CSF analysis.
- CSF hypocretin-1 levels were measured and compared between HAT patients (n=25), narcoleptic patients (n=26), and neurologic controls (n=53).
- Polysomnography was performed on 17 HAT patients.
Main Results:
- CSF hypocretin-1 levels were significantly higher in HAT patients (423.2 pg/mL) than in narcoleptic patients (40.16 pg/mL) but lower than in neurologic controls (517.32 pg/mL).
- One HAT patient had undetectable hypocretin levels, and another had intermediate levels, both reporting excessive daytime sleepiness.
- No significant differences in CSF hypocretin-1 levels were observed between HAT stages, but lower levels correlated with major sleep-wake cycle disruptions.
Conclusions:
- The hypocretin system is not solely implicated in Tb.g. HAT.
- Dysfunction within the hypothalamic hypocretin region may contribute to the sleep disturbances observed in African trypanosomiasis.
- Further research is needed to fully elucidate the role of hypocretins in HAT pathophysiology.
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