Meyerhoff D J, Bloomer C, Cardenas V, Norman D, Weiner M W, Fein G
Department of Veterans Affairs Medical Center, Department of Radiology, University of California San Francisco, 94121, USA.
Neurology. 1999 Mar 23;52(5):995-1003. doi: 10.1212/wnl.52.5.995.
To determine whether the concentrations of the neuronal marker N-acetylaspartate (NAA) and the choline-containing metabolites (Cho) are altered in the subcortical brain of HIV+ patients who are cognitively normal and clinically asymptomatic, and to determine whether these alterations are greater in the presence of cognitive impairments and clinical symptoms.
Pathologic studies suggest that subcortical gray matter carries a heavy HIV load, and neuropsychological test results are consistent with involvement of subcortical and frontostriatal brain systems in HIV disease. Noninvasive proton magnetic resonance spectroscopy (1H MRS) suggests neuronal preservation and macrophage infiltration in the subcortical brain of clinically symptomatic and cognitively impaired HIV+ individuals. Improved 1H MRS methods may allow the early detection of metabolite alterations in the subcortical brain of asymptomatic HIV+ individuals.
Two-dimensional 1H MRS imaging was performed on 30 HIV- control subjects and 70 HIV+ patients with varying severities of systemic disease and neuropsychological impairments, but without cerebral opportunistic infections.
Subcortical Cho was elevated in HIV+ patients compared with control subjects regardless of the presence or absence of cognitive impairment or clinical symptoms. Subcortical NAA was lower than control NAA only in severely cognitively impaired HIV+ subjects. Subcortical NAA correlated with performance on a variety of neuropsychological tests but not with Centers for Disease Control clinical stage, whereas high-thalamic Cho was associated with low CD4 lymphocyte counts.
1H MRS imaging detects higher Cho in subcortical brain early in HIV disease, when individuals are clinically and neuropsychologically asymptomatic, whereas lower NAA is only found in subcortical brain in individuals with severe neuropsychological impairments. Quantitative 1H MRS imaging may play a role in the objective assessment of the presence, magnitude, and progression of brain involvement in HIV infection.
确定认知正常且无临床症状的HIV阳性患者的皮质下脑区中神经元标志物N - 乙酰天门冬氨酸（NAA）和含胆碱代谢物（Cho）的浓度是否发生改变，并确定在存在认知障碍和临床症状时这些改变是否更明显。
病理研究表明皮质下灰质携带大量HIV病毒载量，神经心理学测试结果与HIV疾病中皮质下和额纹状体脑系统受累一致。无创质子磁共振波谱（1H MRS）提示有临床症状和认知障碍的HIV阳性个体的皮质下脑区存在神经元保留和巨噬细胞浸润。改进的1H MRS方法可能有助于早期检测无症状HIV阳性个体皮质下脑区的代谢物改变。
对30名HIV阴性对照受试者和70名患有不同严重程度全身性疾病和神经心理学障碍但无脑部机会性感染的HIV阳性患者进行二维1H MRS成像。
无论有无认知障碍或临床症状，HIV阳性患者的皮质下Cho均高于对照受试者。仅在严重认知障碍的HIV阳性受试者中，皮质下NAA低于对照NAA。皮质下NAA与多种神经心理学测试的表现相关，但与疾病控制中心临床分期无关，而丘脑Cho升高与CD4淋巴细胞计数低有关。
1H MRS成像在HIV疾病早期，即个体临床和神经心理学无症状时，检测到皮质下脑区Cho升高，而仅在有严重神经心理学障碍的个体的皮质下脑区发现较低的NAA。定量1H MRS成像可能在客观评估HIV感染中脑受累的存在、程度和进展方面发挥作用。
