Impaired functional connectivity of thalamus in Alzheimer' s disease explored by resting state functional magnetic resonance imaging / 中华神经科杂志

ABSTRACT

Objective To study the functional connectivity (FC) pattern of thalamus in patients with Alzheimer' s disease (AD).Methods In the present study,resting state functional magnetic resonance imaging (MRI) data were obtained from 30 patients with AD and 26 subjects with normal cognition (NC).The altered functional connectivity pattern in AD was evaluated by comparing to NC.Then a correlation analysis was performed between the strength of FC of the identified regions and various clinical variables for evaluating the relationships between the strength of FC and the cognitive abilities (MMSE,immediate recall and delayed recall of Auditory Verbal Learning Test) of the AD patients.Results The MMSE(19.7 ± 4.1),immediate recall (2.8 ± 1.7) and delayed recall (0.7 ± 1.3) of Auditory Verbal Learning Test in AD patients were lower than NC group (28.8 ± 1.0,5.9 ± 1.2,5.7 ± 2.2 ; t =11.09,8.09,10.51,all P ＜0.05).Compared to NC,AD patients showed decreased FC between the left thalamus and several regions of brain including right posterior/middle cingulate cortex (PCC/MCC.R),left medial prefrontal cortex (MPFC.L) and right superior frontal gyms/medial prefrontal cortex (SFG/MPFC.R).For the right thalamus,decreased FC was found in SFG/MPFC.R,PCC/MCC.R and right hippocampus.We also found increased FC between the bilateral thalamus and many regions of brain including inferior temporal gyrus,medial temporal gyrus,SFG,postcentral gyrus,paracentral lobule,inferior frontal gyms and insula.Significant correlations between the fitted FC strength and clinical variables were also detected.Conclusions FC pattern of thalamus in AD group is impaired.Increased FC in AD may indicate the presence of a compensatory mechanism.The alteration is related with cognitive function in AD.