Résumé
Objective:To explore the association between the spontaneous neural activity and memory function in depressive patients with different sleep quality.Methods:Totally 58 patients with depressive disorder and 58 gender-, age-, education-matched healthy controls (HC) completed 3.0 T MRI Scanning and clinical assessment including Wechsler memory scale (WMS), 24 Hamilton depression scale(HAMD-24) and Pittsburgh sleep quality index (PSQI). According to the score of PSQI, patients were divided into poor sleep quality group (PS, n=38) and good sleep quality group (GS, n=20). Amplitude of low frequency fluctuations (ALFF) were calculated and compared among three groups.Correlation analyses between the brain activity and the score of WMS were conducted as well. Results:Memory quotient of WMS showed differences among three groups( F=14.163, P<0.01), and the lowest score was found in patients with low sleep quality.The brain areas showed significant differences among three groups located in the left medial superior frontal gyrus (lmSFG, MNI: x=-10, y=30, z=58; K=56), right orbital inferior frontal gyrus (roIFG, MNI: x=26, y=20, z=-26; K=24) and left middle frontal gyrus (lMFG, MNI: x=-40 y=32, z=42; K=25) (voxel size P<0.001, cluster size P<0.05, GRF corrected). Compared with GS group, the ALFF of PS group showed significantly increased in the lmSFG, which was negatively correlated with memory quotient ( r=-0.327, P=0.045) and short term memory( r=-0.388, P=0.016). Compared with HC group, the ALFF of PS group showed increased in the lmSFG and lMFG, GS group showed increased ALFF in the roIFG. Conclusion:The impairment of memory function is more serious in patients with depression of low sleep quality, and the activity of frontal lobe is abnormally increased, which is related to memory function.Their association suggests that poor sleep quality in depressive patients may impair memory function by disrupting neural plasticity and synaptic pruning in the frontal lobes.