Semel Institute for Neuroscience and Biobehavioral Studies, University of California Los Angeles, Los Angeles, CA, USA.
Psychopharmacology (Berl). 2010 Mar;209(1):13-24. doi: 10.1007/s00213-009-1761-7. Epub 2010 Jan 27.
Previous studies revealed microstructural abnormalities in prefrontal white matter and corpus callosum of long-term abstinent chronic methamphetamine abusers. In view of the importance of the early abstinence period in treatment retention, we compared 23 methamphetamine-dependent subjects abstinent from methamphetamine for 7-13 days with 18 healthy comparison subjects. As certain metabolic changes in the brain first manifest after early abstinence from methamphetamine, it is also possible that microstructural white-matter abnormalities are not yet present during early abstinence.
Using diffusion tensor imaging at 1.5 T, fractional anisotropy (FA) was measured in prefrontal white matter at four inferior-superior levels parallel to the anterior commissure-posterior commissure (AC-PC) plane. We also sampled FA in the corpus callosum at the midline and at eight bilateral, fiber-tract sites in other regions implicated in effects of methamphetamine.
The methamphetamine group exhibited lower FA in right prefrontal white matter above the AC-PC plane (11.9% lower; p = 0.007), in midline genu corpus callosum (3.9%; p = 0.019), in left and right midcaudal superior corona radiata (11.0% in both hemispheres, p's = 0.020 and 0.016, respectively), and in right perforant fibers (7.3%; p = 0.025). FA in left midcaudal superior corona radiata was correlated with depressive and generalized psychiatric symptoms within the methamphetamine group.
The findings support the idea that methamphetamine abuse produces microstructural abnormalities in white matter underlying and interconnecting prefrontal cortices and hippocampal formation. These effects are already present during the first weeks of abstinence from methamphetamine and are linked to psychiatric symptoms assessed during this period.
先前的研究表明，长期戒断的慢性甲基苯丙胺滥用者的前额叶白质和胼胝体存在微观结构异常。鉴于早期戒断期在治疗保留中的重要性，我们比较了 23 名甲基苯丙胺依赖者，他们在 7-13 天内戒断了甲基苯丙胺，与 18 名健康对照者进行了比较。由于大脑中的某些代谢变化首先在早期戒断甲基苯丙胺后表现出来，因此在早期戒断期间也可能不存在微观结构白质异常。
使用 1.5 T 的弥散张量成像，在与前连合后连合（AC-PC）平面平行的四个下至上水平测量前额叶白质的分数各向异性（FA）。我们还在胼胝体中线和其他与甲基苯丙胺作用相关的八个双侧纤维束部位测量了 FA。
甲基苯丙胺组在 AC-PC 平面上方的右侧前额叶白质（低 11.9%；p=0.007）、中线胼胝体膝部（低 3.9%；p=0.019）、左侧和右侧中尾上放射冠（双侧均低 11.0%，p 值分别为 0.020 和 0.016）以及右侧穿通纤维（低 7.3%；p=0.025）中表现出较低的 FA。甲基苯丙胺组中左侧中尾上放射冠的 FA 与抑郁和广泛性精神症状相关。
这些发现支持了这样一种观点，即甲基苯丙胺滥用会导致前额叶皮质和海马结构下和相互连接的白质的微观结构异常。这些影响在戒断甲基苯丙胺的第一周就已经存在，并与这段时间内评估的精神症状有关。
