Chang Linda, Alicata Daniel, Ernst Thomas, Volkow Nora
Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI 96813, USA.
Addiction. 2007 Apr;102 Suppl 1:16-32. doi: 10.1111/j.1360-0443.2006.01782.x.
To review structural, chemical and metabolic brain changes, particularly those in the basal ganglia, in individuals who used methamphetamine, as well as in children with prenatal methamphetamine exposure.
Magnetic resonance imaging (MRI) and positron emission tomography (PET) studies that evaluated brain structural, chemical and metabolite changes in methamphetamine subjects, or children with prenatal methamphetamine exposure, were reviewed and summarized. Relevant pre-clinical studies that provided insights to the interpretations of these imaging studies were also reviewed.
In adults who used methamphetamine, MRI demonstrates enlarged striatal volumes, while MR spectroscopy shows reduced concentrations of the neuronal marker N-acetylasparate and total creatine in the basal ganglia. In contrast, children with prenatal methamphetamine exposure show smaller striatal structures and elevated total creatine. Furthermore, PET studies consistently showed reduced dopamine transporter (DAT) density and reduced dopamine D(2) receptors in the striatum of methamphetamine subjects. PET studies also found lower levels of serotonergic transporter density and vesicular monoamine transporter (VMAT2) across striatal subregions, as well as altered brain glucose metabolism that correlated with severity of psychiatric symptoms in the limbic and orbitofrontal regions.
Neuroimaging studies demonstrate abnormalities in brain structure and chemistry convincingly in individuals who used methamphetamine and in children with prenatal methamphetamine exposure, especially in the striatum. However, many important questions remain and larger sample sizes are needed to validate these preliminary observations. Furthermore, longitudinal studies are needed to evaluate the effects of treatment and abstinence on these brain changes and to determine whether imaging, and possibly genetic, markers can be used to predict treatment outcome or relapse.
回顾使用甲基苯丙胺的个体以及产前暴露于甲基苯丙胺的儿童的大脑结构、化学和代谢变化,尤其是基底神经节的变化。
对评估甲基苯丙胺使用者或产前暴露于甲基苯丙胺的儿童大脑结构、化学和代谢物变化的磁共振成像(MRI)和正电子发射断层扫描(PET)研究进行了综述和总结。还综述了为这些影像学研究的解释提供见解的相关临床前研究。
在使用甲基苯丙胺的成年人中,MRI显示纹状体体积增大,而磁共振波谱显示基底神经节中神经元标志物N-乙酰天门冬氨酸和总肌酸的浓度降低。相比之下,产前暴露于甲基苯丙胺的儿童显示纹状体结构较小且总肌酸升高。此外,PET研究一致显示甲基苯丙胺使用者纹状体中的多巴胺转运体(DAT)密度降低和多巴胺D(2)受体减少。PET研究还发现整个纹状体亚区域的血清素能转运体密度和囊泡单胺转运体(VMAT2)水平较低,以及与边缘和眶额区域精神症状严重程度相关的大脑葡萄糖代谢改变。
神经影像学研究令人信服地证明了使用甲基苯丙胺的个体以及产前暴露于甲基苯丙胺的儿童大脑结构和化学异常,尤其是在纹状体中。然而,许多重要问题仍然存在,需要更大的样本量来验证这些初步观察结果。此外,需要进行纵向研究来评估治疗和戒断对这些大脑变化的影响,并确定影像学以及可能的基因标志物是否可用于预测治疗结果或复发。