Functional Magnetic Resonance Imaging in Narcolepsy and the Kleine-Levin Syndrome

• Main Authors: Maria eEngström, Tove eHallböök, Attila eSzakacs, Thomas eKarlsson, Anne-Marie eLandtblom
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2014-06-01
• Series: Frontiers in Neurology
• Subjects: Hypothalamus; Kleine-Levin Syndrome; Narcolepsy; Thalamus; ascending arousal system; Hypersomnia
• Online Access: http://journal.frontiersin.org/Journal/10.3389/fneur.2014.00105/full

This work aims at reviewing the present state of the art when it comes to understandingthe pathophysiology of narcolepsy and the Kleine-Levin syndrome from a neuroimaging pointof view. This work also aims at discussing future perspectives of functional neuroimaging in these sleep disorders. We focus on functional magnetic resonance imaging (fMRI), which is atechnique for in vivo measurements of brain activation in neuronal circuitries under healthy andpathological conditions. fMRI has significantly increased the knowledge on the affected neuronalcircuitries in narcolepsy and the Kleine-Levin syndrome. It has been shown that narcolepsy isaccompanied with disturbances of the emotional and the closely related reward systems. Inthe Kleine Levin syndrome, fMRI has identified hyperactivation of the thalamus as a potentialbiomarker that could be used in the diagnostic procedure. The fMRI findings in both narcolepsyand the Kleine-Levin syndrome are in line with previous structural and functional imaging studies.We conclude that fMRI in combination with multimodal imaging can reveal important detailsabout the pathophysiology in narcolepsy and the Kleine-Levin syndrome. In the future, fMRIpossibly gives opportunities for diagnostic support and prediction of treatment response inindividual patients.