Purpose of ReviewClinical presentation of central hypersomnolence disorders, including narcolepsy type 1 and 2 and idiopathic hypersomnia, is often similar, and determining the correct diagnosis... Show morePurpose of ReviewClinical presentation of central hypersomnolence disorders, including narcolepsy type 1 and 2 and idiopathic hypersomnia, is often similar, and determining the correct diagnosis remains challenging. Neuroimaging techniques have provided valuable insights into the pathophysiology of narcolepsy and idiopathic hypersomnia. Here, we review current structural and functional brain imaging findings in central hypersomnolence disorders and discuss the future perspectives of neuroimaging in these sleep disorders.Recent FindingsMost studies have focused on narcolepsy type 1 (or narcolepsy with cataplexy), showing inconsistent but extensive structural differences in the hypothalamus and its normally widespread projections. Functional studies have mainly focused on resting-state or emotion regulation in narcolepsy type 1 and have revealed disturbed activity in limbic and mesolimbic structures in relation to cataplexy. Finally, recent studies suggest a disruption of the default-mode network in patients with idiopathic hypersomnia.SummaryMost neuroimaging studies to date have been conducted in small samples, while narcolepsy type 2 (or narcolepsy without cataplexy) and idiopathic hypersomnia remain relatively understudied. Larger studies with consistent clinical phenotyping should be the focus of future investigations. In addition, multi-modal imaging methods will be crucial to resolve previous inconsistencies and identify reliable objective biomarkers that could aid in understanding the pathophysiology and potentially support the diagnostic process. Show less
The premonitory phase and early phase of both spontaneous and nitroglycerin-triggered migraine attacks were explored in this thesis, in association with clinical modulators and trigger factors.... Show moreThe premonitory phase and early phase of both spontaneous and nitroglycerin-triggered migraine attacks were explored in this thesis, in association with clinical modulators and trigger factors. Clinical research strategies, experimental designs, neuroimaging techniques and biochemical methods have revealed clinical risk factors, biochemical modulators and pharmacological triggers. Furthermore, newly discovered hypothalamus-specific alterations in metabolism and perfusion in the early phases of the migraine attack were described. Taken together, these results suggest that each migraine attack starts well before the initiation of the headache phase. The hypothalamus is postulated to have a pivotal role in the early phases of the migraine attack, and possibly affects attack susceptibility interictally as well. Show less
