The Changes Of Memory And TNF-α In The Palicnls With Primary Insomnia

Background Insomnia is the most common sleep disorder，it can impair the patients’cognitive functions such as alertness, memory, executive function, and thelearning-memory difficulty is the most common one. Previous study of insomniagenerally did not distinguish the types of insomnia, perhaps confounded depression,anxiety and other potentially factors, therefore it was not clear that whether the patientswith primary insomnia had cognitive function damage. Studies had shown manysleep-related diseases existed abnormal expression of inflammatory cytokines. Toexplore the relationship between inflammatory cytokines and insomnia, previousexperiments utilized the means of sleep deprivation or injection of exogenousinflammatory cytokines. However subjects were often healthy young people, and theeffect of the experiments was short-term, meanwhile there was a great deal of differencebetween sleep deprivation and the natural course of insomnia, therefore it was not clearthat whether the patients with primary insomnia had changes in inflammatory cytokines.Objective To explore spatial memory ability and TNF-α serum level changes of the PIand depression comorbidity of insomnia (DCI) in patients, explicit whether the changesof spatial memory function is associated with TNF-α further.Methods：According to diagnostic criteria in the DSM-IV，30PI patients(9malecases,21female cases) and30DCI patients(10male cases,20female cases) werecollected, and30normal controls(10male cases,20female cases) were healthyvolunteers. After their background information was collected, the quality of sleep was assessed by Pittsburgh Sleep Quality Index (PSQI), the severity of depression wasevaluated by17-item Hamilton Depression Rating Scale (HMAD-17Edition), and theoverall cognitive function was detected by Montreal Cognitive Assessment Scale(MoCA). Afterwards, the memory functions in all subjects, including spatial workingmemory, object working memory, spatial reference memory, object reference memoryand object recognition memory were respectively determined by “nine boxes maze”task and image recognition experiment.About2ml venous blood was obtained at thenext day8AM, the serum was stored frozen under–80℃. The serum concentrationsof TNF-α were detected by Enzyme-linked immunosorbent assay (ELISA) using TNF-αkit.Results There was compatible background information consisted of sex, age and yearseducated between PI group, ACI group and control group (Ps>0.05). The scores ofPSQI in PI group and DCI group were both more than those in the controls (Ps <0.05),however, there were no significant differences in the scores of PSQI (Ps>0.05) betweenPI group and DCI group. The scores of HMAD-17in PI group and DCI group were alsoboth more than those in the controls (Ps <0.05), and scores of HMAD in PI group wereless than those in the DCI group (Ps <0.05). The errors of spatial working memory andobject recognition memory in PI group were more than those in the controls (Ps <0.05),but the errors of object reference memory, spatial reference memory and objectworking memory show no significant differences between PI group and control group（Ps＞0.05）, the errors of object working memory, object reference memory, spatialworking memory and spatial reference memory were both more than those in thecontrols (Ps <0.05). Spearman’s correlation analysis showed that the errors of objectreference memory spatial reference memory, object working memory and spatialworking memory were positively correlated with the TNF-α level (rs=0.295，0.277，0.288，0.427and0.380，Ps＜0.05); so were the scores of PSQI, sleep quantity, the onsetof sleep, sleep time, sleep efficient, sleep disorders, daytime function and HMAD-17 (Ps<0.001).Conclusion PI patients have a certain amount of memory (space work and objectrecognition memory) damaged, but the range of the damage is less than DCI patients(spatial memory, object memory and object recognition memory); the increased TNF-αsecretion of PI patients, which may involve the memory loss.