| Background and purpose Insomnia,which is also known as primary insomnia,is a sleep disorder characterized by difficulties in falling asleep,staying sleep,waking up frequently during the night and having trouble going back to sleep,and/or waking up too early in the morning,together coupled with or without daytime functional impairment.Epidemiological investigation shows that it is now one of the most common health problems affecting approximately 6%-30% of the population in the world and 9.2%-11.2% adults in our country.The research on insomnia is also carried out from the Clinical symptom to the cause of this disease,but we are still not very clear about the etiology and mechanism of insomnia.Most researchers agree that it is caused predominately by both biological and physiological factors in the neuropathological mechanism of insomnia.In diagnostic medical imaging both functional magnetic resonance imaging(FMRI)and positron emission tomography computed tomography(PET/CT)are widely utilized to study insomnia,They focused on the neurological or functional impairment in patients with insomnia,There are few studies on the Neurobiological change mechanism of insomnia.Excessive arousal is the core symptom of insomnia,and it is the result of the intra-interactions of a number of neurotransmitters which have different functions on the sleep.Dopamine the most important neurotransmitters in the study of insomnia,is recognized as an important material basis for the promotion and maintenance of wakefulness.PET/CT is widely used in neurotransmitter studies due to its ability of tracing body molecules invasively.Sleep deprivation PET/CT neuroreceptor imaging on the animal model has shown that abnormal expression or function of dopamine neurotransmitter.It is suggested that sleep disorders may be related to the changes of dopamine neurotransmitters in the brain,but now there are few studies on PET/CT neurotransmitters.In this study,we are monitoring the dopamine receptor binding imaging by 11C-raclopride positron emission tomography(PET)/computed tomography(CT)scaning.We hoped to observe whether there are abnormal changes of endogenous dopamine in patients with insomnia,by investigating the change of neurotransmitters information in dopamine pathway and to explain the reasons for the change of dopamine pathway and its relationship with the behaviour change and to provide the molecular imaging basis for the study of the pathological mechanism of insomnia..Materials and methods Subject: Insomnia patients and volunteers without insomnia were recruited from January 2016 to December 2016 at the Department of Neurology of the people's Hospital of Zhengzhou University.There were fourteen(14)females and 1 male in the insomnia group(age 44.3±8.65),and 12 females and 3 males in the control group(age 40.5±8.98).There was no statistically significant difference between the two groups(gender ?2=1.154,p=0.283,age t=1.180,p=0.248).All subjects met the inclusion and exclusion criteria.Examination method: Subjects were required to stop taking coffee,tea and alcoholic food for two weeks and maintain normal sleep habits.Firstly,scores from the PSQI,HAMD depression scale,instantaneous memory,and graphic memory scale were collected.3D T1 and Structural MRI scan were conducted two days later on Siemens Prisma 3.0T MR.Two days after the MRI scan,the PET / CT Scan were conducted.The drugs we used are 11C-raclopride.then we analyzed the data of PET/CT,f MRI and behavioral.Data processing: The dynamic PET data and 3DT1 magnetic resonance data were extracted,segmented and corrected by the Molecular Imaging and Kinetic Analysis Toolbox(MIAKAT),based on MATLAB.From the parameter data,we obtained the whole brain parameters as well as the time-radioactivity curve of the region of interest and the binding potential value(BPnd value).Statistical analysis: SPSS 20.0 software was used to compare the difference of the binding potential between the Nucleus accumbens,the caudate nucleus and the putamen nucleus.Bilateral striatal(Nucleus accumbens,caudate nucleus and putamen)dopamine D2 receptor binding potential between the patient and control were compared,and ipsilateral striatal(Nucleus accumbens,caudate nucleus and putamen)dopamine D2 receptor binding potential between the patient and control were compared,respectively.The correlation analysis between bilateral striatal dopamine D2 receptor binding potential and behavioral changes(the Pittsburgh sleep quality index,the HAMD depression scale,instantaneous memory and graphic memory scale)of the patients were conducted.Result There were significant difference in the PSQI(t=13.127 p=0),HAMD depression scale(t=10.273 p=0),instantaneous memory(t=-4.888 p=0),and graphic memory scale(t=-2.624 p=0.014)between Patients with insomnia and normal volunteers? Insomnia group: There were no significant difference in the dopamine D2 receptor binding potential between left and right sides Nucleus accumbens,caudate nucleus and putamen control group: There were no significant difference in the dopamine D2 receptor binding potential between left and right sides Nucleus accumbens,caudate nucleus and putamen Patients with insomnia were lower than normal volunteers in the ipsilateral Nucleus accumbens,caudate nucleus and putamen dopamine D2 receptor binding potential,and the difference was statistically significant,except the one for the Right caudate nucleus.There was a negative correlation between Nucleus accumbens,caudate nucleus and putamen dopamine D2 receptor binding potential and Insomnia duration in the patients with insomnia,the difference was statistically significant.Conclusion The Dopamine D2 receptor binding potential of Sleep related dopaminergic pathway in insomnia patients was reduced.As the duration of onset of insomnia increases,the nucleus accumbens,caudate nucleus,putamen receptor binding potentials declined.The results showed that there were abnormalities of dopamine neurotransmitter system in patients with insomnia and it is associated with the pathogenesis of insomnia. |
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