| Background:Narcolepsy is a sleep-wake disorder,characterized by excessive daytime sleepiness,sudden loss of muscle tone triggered by emotions(cataplexy)and nocturnal sleep disorder,which including sleep paralysis,hypnagogic hallucinations,nocturnal sleep disruption,festless sleep,decreased sleep quality,incubus and REM sleep behavior disorder.Besides these symptoms assocated with sleep-wake disorder,central obesity,obstructive sleep apnea syndrome(OSAS),migraine,regulation of emotion,congnitive impairments and mood disorder can be seen in narcolepsy.Apoptosis of hypocretin cells caused by abnormol autoimmune reaction plays an important role in the pathogenesis of narcolepsy,especially the patient with catalepsy.Over the last two decades,numerous neuroimaging studies have attempted to clarify the machanisms of the brain dysfunction in narcolepsy.But,the result is controversial so far.Diffusion tensor imaging(DTI)is a unique form of magnetic resonance imaging(MRI)technique that enables non-invasive,in vivo visualiztion of the structural integrity of fiber tracts and neuronal tissue,as indicated by the values obtained for frational anisotropy(FA),apparent diffusion coefficient(ADC)and fiber tractrography(FT).The aim of this study is to investigate:1.the brain dysfunction in narcolepsy,as reflected by FA,ADC and FT;2.the correlation between brain dysfunction and clinical festures,regulation of emotion,congnitive impairments in narcolepsy.Methods:We select a total of 7 narcolepsy and age-and-sex matched healthy controls in the Second Hospital of ShanDong University from February,2015 to April,2017.First,neuropsychological scales tests,such as,Epworth sleepiness scale(ESS),CES-DC,Beck depression inventory-Ⅱ(BDI-Ⅱ)and Montreal cognitive scale(MoCA)are performed on all participants.All participants are scanned by DTI.All the original images are processed by post-processing software--Functool in CTE workstation:1.FA and ADC are measured at superior frontal gyrus、precentral gyrus、poetcentral gyrus、white matter of frontal parietal lobe、precuneus、inferior parietal lobule、inferior frontal gyrus、supramarginal gyrus、anterior cingulate、posterior cingulate、corpus callosum genu、caudate nucleus、thalamus、anterior limd of internal capsule、parahippocampal gyrus、hypothalamus、fronto-orbital cortex、temporal region、pons and amygdala;2.Using the FACT algorithm describes fiber tracts through hypothalamus.Statistical tools IBM SPSS 17.0 is applied in order to analyze the correlation between imaging datas and clinical festures,neuropsychological scales tests.Results:1.The number、gender、age、BDI-H and MOCA of narcolepsy do no differ from normal.There are significant differences in BMI、ESS between narcolepsy and narmol.2.The FA values at left superior frontal gyrus、right inferior frontal gyrus、right supramarginal gyrus、bilateral caudate nucleus and anterior limd of internal capsule are significantly lower than those in the controls.3.The ADC values at left precentral gyrus、left poetcentral gyrus and left inferior parietal lobule are significantly higher than those in the controls.4.There are no correlations between FA、ADC and age、progress、BMI、ESS in narcolepsy.5.The fiber density through hypothalamus area is significantly lower than those in the controls.Conclusions:7 narcolepsy and age-and-sex matched healthy controls are scanned by DTI,revealing microstructural changes in the hypothalamus、caudate nucleus、anterior limd of internal capsule and widespread cerebral cortex,including superior frontal gyrus、inferior frontal gyrus、supramarginal gyrus、precentral gyrus、poetcentral gyrus and inferior parietal lobule.The findings support the theory that the hypothalamic hypocretin system and its fiber projection area are directly involved in the pathogenesis of narcolepsy. |
