TY - JOUR
T1 - Neuroimaging in Narcolepsy and Idiopathic Hypersomnia
T2 - from Neural Correlates to Clinical Practice
AU - Gool, Jari K.
AU - Cross, Nathan
AU - Fronczek, Rolf
AU - Lammers, Gert Jan
AU - van der Werf, Ysbrand D.
AU - Dang-Vu, Thien Thanh
PY - 2020/12
Y1 - 2020/12
N2 - Purpose of Review: Clinical 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 Findings: Most 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. Summary: Most 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.
AB - Purpose of Review: Clinical 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 Findings: Most 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. Summary: Most 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.
KW - Hypocretin
KW - Hypothalamus
KW - Idiopathic hypersomnia
KW - Narcolepsy
KW - Neuroimaging
UR - http://www.scopus.com/inward/record.url?scp=85095724304&partnerID=8YFLogxK
U2 - https://doi.org/10.1007/s40675-020-00185-9
DO - https://doi.org/10.1007/s40675-020-00185-9
M3 - Review article
SN - 2198-6401
VL - 6
SP - 251
EP - 266
JO - Current Sleep Medicine Reports
JF - Current Sleep Medicine Reports
IS - 4
ER -