Department of Medical Imaging, Guangdong Second Provincial General Hospital, Guangzhou, China.
Department of Diagnostic Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Psychiatry Clin Neurosci. 2020 Jan;74(1):77-83. doi: 10.1111/pcn.12940. Epub 2019 Nov 4.
Prescription opioids are psychoactive substances that can elicit many neuropsychological effects. There are no studies that directly demonstrate the effects of prescription opioid addiction (POA) on the human brain. This study aimed to quantify γ-aminobutyric acid (GABA) and glutamate (Glu) levels in the prefrontal cortex (PFC) of POA patients using proton magnetic resonance spectroscopy ( H-MRS), and to explore their association with impulsive behavior and cognitive impairment.
Thirty-five patients with a definitive clinical diagnosis of codeine-containing cough syrup dependence and 35 matched healthy controls underwent neuropsychological assessments, namely the Barratt Impulsiveness Scale (BIS-11) and the Montreal Cognitive Assessment Scale (MoCA). Point-resolved spectroscopy was performed to detect GABA and glutamate within the medial PFC, and the corresponding levels were estimated using jMRUI and corrected for fraction of cerebrospinal fluid in the H-MRS voxel. The difference in metabolite levels between groups and the correlation between metabolite levels and psychometric scores in patients were analyzed statistically.
The peak level predominantly consisting of GABA with a relatively small influence of other chemicals (GABA+) was lower and that of glutamate was higher in the PFC of POA patients than in healthy controls. GABA+ levels correlated negatively with BIS-11 scores but correlated positively with MoCA scores. In contrast, glutamate levels showed a positive correlation with BIS-11 scores but no significant correlation with MoCA scores.
The quantitative in vivo measurement of GABA and glutamate levels in the PFC by H-MRS could be a reliable way to evaluate impulsivity and cognitive function of POA.
处方类阿片类药物是具有精神活性的物质，可引起许多神经心理学效应。目前尚无研究直接证明处方类阿片成瘾（POA）对人类大脑的影响。本研究旨在通过质子磁共振波谱（ 1 H-MRS）定量测定 POA 患者前额叶皮质（PFC）中的γ-氨基丁酸（GABA）和谷氨酸（Glu）水平，并探讨其与冲动行为和认知功能障碍的关系。
35 例经临床确诊的含可待因咳嗽糖浆依赖患者和 35 名匹配的健康对照者接受了神经心理学评估，即巴瑞特冲动量表（BIS-11）和蒙特利尔认知评估量表（MoCA）。采用点分辨波谱法检测内侧 PFC 中的 GABA 和谷氨酸，使用 jMRUI 估计相应水平，并对 1 H-MRS 体素中的脑脊液分数进行校正。对两组间代谢物水平的差异以及患者代谢物水平与心理计量评分的相关性进行统计学分析。
POA 患者 PFC 中的 GABA 主要峰（GABA+）水平较低，谷氨酸水平较高，而其他化学物质的影响相对较小。GABA+水平与 BIS-11 评分呈负相关，与 MoCA 评分呈正相关。相比之下，谷氨酸水平与 BIS-11 评分呈正相关，与 MoCA 评分无显著相关性。
通过 1 H-MRS 对 PFC 中 GABA 和谷氨酸水平进行定量活体测量，可能是评估 POA 患者冲动性和认知功能的可靠方法。
