title: White matter alterations in narcolepsy patients with cataplexy: tract-based spatial statistics.
abstract: Functional imaging studies and voxel-based morphometry analysis of brain magnetic resonance imaging showed abnormalities in the hypothalamus-thalamus-orbitofrontal pathway, demonstrating altered hypocretin pathway in narcolepsy. Those distinct morphometric changes account for problems in wake-sleep control, attention and memory. It also raised the necessity to evaluate white matter changes. To investigate brain white matter alterations in drug-naïve narcolepsy patients with cataplexy and to explore relationships between white matter changes and patient clinical characteristics, drug-naïve narcolepsy patients with cataplexy (n = 22) and healthy age- and gender-matched controls (n = 26) were studied. Fractional anisotropy and mean diffusivity images were obtained from whole-brain diffusion tensor imaging, and tract-based spatial statistics were used to localize white matter abnormalities. Compared with controls, patients showed significant decreases in fractional anisotropy of white matter of the bilateral anterior cingulate, fronto-orbital area, frontal lobe, anterior limb of the internal capsule and corpus callosum, as well as the left anterior and medial thalamus. Patients and controls showed no differences in mean diffusivity. Among patients, mean diffusivity values of white matter in the bilateral superior frontal gyri, bilateral fronto-orbital gyri and right superior parietal gyrus were positively correlated with depressive mood. This tract-based spatial statistics study demonstrated that drug-naïve patients with narcolepsy had reduced fractional anisotropy of white matter in multiple brain areas and significant relationship between increased mean diffusivity of white matter in frontal/cingulate and depression. It suggests the widespread disruption of white matter integrity and prevalent brain degeneration of frontal lobes according to a depressive symptom in narcolepsy.
authors.affiliation: Department of Neurology, Neuroscience Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yun K
authors.initials: YK
authors.lastname: Park
authors.affiliation: Computational NeuroImage Analysis Laboratory, Department of Biomedical Engineering, Hanyang University, Seoul, Korea.
authors.forename: Oh-Hun
authors.initials: OH
authors.lastname: Kwon
authors.affiliation: Department of Neurology, Neuroscience Center, Sungkyunkwan University School of Medicine, Seoul, Korea.|Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea.
authors.forename: Eun Yeon
authors.initials: EY
authors.lastname: Joo
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jae-Hun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Computational NeuroImage Analysis Laboratory, Department of Biomedical Engineering, Hanyang University, Seoul, Korea.
authors.forename: Jong M
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sung T
authors.initials: ST
authors.lastname: Kim
authors.affiliation: Department of Neurology, Neuroscience Center, Sungkyunkwan University School of Medicine, Seoul, Korea.|Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea.
authors.forename: Seung B
authors.initials: SB
authors.lastname: Hong
mesh_terms: D000293:Adolescent; D000328:Adult; D016880:Anisotropy; D002385:Cataplexy / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000473:pathology; D002648:Child; D003337:Corpus Callosum / Q000000981:diagnostic imaging / Q000473:pathology; D003863:Depression / Q000150:complications / Q000473:pathology; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D066127:White Matter / Q000000981:diagnostic imaging / Q000473:pathology*; D055815:Young Adult
keywords: brain; diffusion tensor imaging; frontal lobe; hypersomnia; mood disorder