Buchsbaum Monte S, Simmons Alan N, DeCastro Alex, Farid Nikdokht, Matthews Scott C
1 Department of Psychiatry, University of California , San Diego, California.
2 Department of Radiology, University of California , San Diego, California.
J Neurotrauma. 2015 Nov 15;32(22):1736-50. doi: 10.1089/neu.2014.3660. Epub 2015 Sep 29.
Individuals with mild traumatic brain injury (TBI) show diminished metabolic activity when studied with positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG). Since blast injury may not be localized in the same specific anatomical areas in every patient or may be diffuse, significance probability mapping may be vulnerable to false-negative detection of abnormalities. To address this problem, we used an anatomically independent measure to assess PET scans: increased numbers of contiguous voxels that are 2 standard deviations below values found in an uninjured control group. We examined this in three age-matched groups of male patients: 16 veterans with a history of mild TBI, 17 veterans with both mild TBI and post-traumatic stress disorder (PTSD), and 15 veterans without either condition. After FDG administration, subjects performed a modified version of the California Verbal Learning Task. Clusters of low uptake voxels were identified by computing the mean and standard deviation for each voxel in the healthy combat veteran group and then determining the voxel-based z-score for the patient groups. Abnormal clusters were defined as those that contained contiguous voxels with a z-score <-2. Patients with mild TBI alone and patients with TBI+PTSD had larger clusters of low uptake voxels, and cluster size significantly differentiated the mild TBI groups from combat controls. Clusters were more irregular in shape in patients, and patients also had a larger number of low-activity voxels throughout the brain. In mild TBI and TBI+PTSD patients, but not healthy subjects, cluster volume was significantly correlated with verbal learning during FDG uptake.
使用正电子发射断层扫描（PET）和（18）F-氟脱氧葡萄糖（FDG）对轻度创伤性脑损伤（TBI）患者进行研究时，发现他们的代谢活动有所减弱。由于爆炸伤在每个患者身上可能并不局限于相同的特定解剖区域，或者可能是弥漫性的，因此显著性概率图谱可能容易出现异常的假阴性检测。为了解决这个问题，我们使用了一种解剖学上独立的测量方法来评估PET扫描：连续体素数量增加，这些体素的值比未受伤对照组低2个标准差。我们在三组年龄匹配的男性患者中进行了此项研究：16名有轻度TBI病史的退伍军人，17名患有轻度TBI和创伤后应激障碍（PTSD）的退伍军人，以及15名没有这两种情况的退伍军人。在给予FDG后，受试者进行了加利福尼亚言语学习任务的修改版。通过计算健康退伍军人组中每个体素的平均值和标准差，然后确定患者组基于体素的z分数，来识别低摄取体素簇。异常簇被定义为那些包含z分数<-2的连续体素的簇。单纯轻度TBI患者和TBI+PTSD患者有更大的低摄取体素簇，并且簇大小显著区分了轻度TBI组与战斗对照组。患者的簇形状更不规则，并且患者全脑低活性体素的数量也更多。在轻度TBI和TBI+PTSD患者中，而不是健康受试者中，簇体积与FDG摄取期间的言语学习显著相关。
