关键词: 脑梗死慢性期; 抑郁状态; 弥散张量成像; 各向异性分数; 前额叶背外侧皮层

Abstract: Objective To study the value of diffusion tensor imaging(DTI) in microstructural changes in brainwhite matter of depressed patients in chronic phase of cerebral infarction and to preliminarily studythe pathogenesis of post-stroke depression(PSD) from the perspective of microstructural changes inbrain white matter.Methods We chose those right-handed patients with first ischemic stroke and infarcts affectedunilateral hemisphere. The patients who are taking antidepressant medication at the time or hada past history of depression were excluded. The demographics and clinical information of allthe patients were collected. At the 90-day follow up, all patients recruited in this part underwentmagnetic resonance imaging(MRI) and Hamilton Rating Scale for Depression(HRSD) andwere separated into two groups according to the score of HRSD:depressed (HRSD≥8) andnon-depressed(HRSD<8) patient groups in chronic phase of cerebral infarction. The fractionalanisotropy(FA) values and laterality index in different regions were measured automatically by theworkstation and compared between the two groups.Results Thirteen patients in depressed state and 15 patients in non-depressed state in chronicphase of cerebral infarction were involved. Depressed patients in chronic phase of cerebralinfarction exhibited significantly decreased FA values in bilateral middle frontal gyrus, comparedwith non-depressed patients(right:468.77±90.14 vs 565.26±112.33, P =0.02; left:452.15±50.24 vs539.16±85.19, P =0.003). No significant differences were observed in the laterality index of allregions between two groups as well as the bilateral FA values of all areas.Conclusion DTI is a sensitive method for detecting the microstructural changes in brain whitematter of depressed patients in chronic phase of cerebral infarction. Decreased FA values inbilateral middle frontal gyrus of depressed patients in chronic phase of cerebral infarction suggestthat damage to the dorsolateral prefrontal circuit might be one of neurobiological mechanism of thedevelopment of depressed state post-stroke.

Key words: Chronic phase of cerebral infarction; Depressed state; Diffusion tensor imaging; Fractional anisotropy; Dorsolateral prefrontal cortex