Magnetic Resonance Imaging Study Of Brain Structure And Cognitive Impairment In AIDS Patients

Since the emergence of human immunodeficiency virus(HIV)in the early 1980s,the virus can penetrate the blood-brain barrier and enter the brain at the early stage of infection,thereby it can distruct the structure and function of the brain.Even receiving the combined antiretroviral therapy(cART),it may also remain in the central nervous system,causing various degrees of brain structure and functional damages in some infected HIV patients.However,the cause of this damage is currently unclear.Magnetic resonance imaging(MRI),one of the most common clinical examination techniques,has many advantages such as,non-invasiveness,high resolution and contrast between tissues and is widely used in the brain science research.Therefore,in this study,we used the three-dimensional high-resolution brain structural MRI to investigate the brain structural changes in patients with acquired immunodeficiency syndrome(AIDS).According to the inclusion criteria,140 AIDS patients,who were serologically HIV-positive and confirmed by the local centers for disease control and prevention,were collected at Zhongnan Hospital of Wuhan University from April 2011 to July 2014.In addition,96 healthy age and gender matched volunteers were selected as controls.Using voxel-based morphometry and surface-based morphometry,the differences in brain gray matter volume,white matter volume and cerebral cortex thickness of each group were analyzed.The correlations between abnormal brain structure and nadir CD4 count,cognitive scores,and treatment duration were also explored.The study may not only provide insights into the pathophysiology of HIV infection,but also provide new ideas for the optimization of treatment methods for AIDS patients.The main results of this study are as follows:(1)Compared with healthy controls,AIDS patients had smaller gray matter volumes in the bilateral middle temporal gyrus,left thalamus and left posterior cerebellum while larger gray matter volumes in the bilateral medial frontal gyrus,left precuneus gyrus and bilateral lingual gyrus.In addition,it was also found that the white matter volumes of the bilateral lenticular nucleus of AIDS patients decreased and the temporal and frontal cortex became thinner.The correlation analysis showed that there were associations between the changed brain volumes in the bilateral middle temporal gyrus,left thalamus,bilateral lenticular nucleus and the nadir CD4 counts,cognitive scores,and treatment duration.(2)Compared with untreated patients,AIDS patients with cART treatment had fewer brain structures showing gray matter volume abnormalities.In addition,the untreated AIDS patients had reduced white matter volumes in the bilateral lenticular nucleus,and thinning of the temporal and frontal cortex.AIDS patients receiving cART treatment had no changes in white matter volume and cortical thickness.(3)Compared with patients without cognitive impairment,AIDS patients with cognitive impairment have more gray matter volume abnormalities.AIDS patients with cognitive impairment have thinning of the frontal and temporal cortex.However,AIDS patients without cognitive impairment had no changes in cortical thickness,Our results indicate that AIDS patients have alterations in the gray matter volume,white matter volume,and cortical thickness.These abnormalities are specific to certain brain regions,and structural changes in some brain regions may cause cognitive impairment.Our results also show that cART can effectively prevent the occurrence of abnormal brain structures to a certain extent,and also emphasize the importance of implementing cART as soon as possible.