Vachha Behroze, Adams Richard C, Rollins Nancy K
Pediatric Developmental Disabilities, Texas Scottish Rite Hospital for Children, Dallas, Tex, USA.
Radiology. 2006 Jul;240(1):194-202. doi: 10.1148/radiol.2401050674.
To prospectively determine anomalies of limbic tracts and to describe the relationship between these anomalies, seen on diffusion-tensor magnetic resonance (MR) and fiber tract (FT) reconstruction images, and learning and memory in children with myelomeningocele (MM) and Chiari II malformation.
The investigation was HIPAA compliant and approved by institutional review boards; informed consent was obtained. In seven male and six female patients (aged 6 months to 16 years) with MM and Chiari II malformation, diffusion-tensor imaging and FT reconstruction were performed. FT reconstruction was generated with fractional anisotropy continuous tracking algorithm and manually drawn regions of interest. Limbic tract abnormalities were assessed on FT reconstruction images by an experienced pediatric neuroradiologist blinded to results of cognitive testing. Nine patients met criteria for memory and learning testing by a trained cognitive neuroscientist blinded to MR results. Exact Wilcoxon rank sum test was used to compare performance with learning and memory tasks in two groups.
Eleven of 13 patients had defects within fornices and/or cingulum; three patients had aberrant fibers of cingulum. In nine patients, six had deficits in general memory; four, in learning; and four, in both. Atresia or hypoplasia of crura and body of fornices was noted in six patients with memory deficits and four patients with learning deficits. Five of six patients with memory deficits and three of four with learning deficits had hypoplasia or atresia of cingulum. Exact Wilcoxon rank sum test demonstrated significantly poorer performance for nonverbal immediate recall tasks in patients with anomalies of the fornix compared with those without (P = .04, exact two-tailed test).
Diffusion-tensor and FT reconstruction images revealed that limbic fiber abnormalities were common in patients with MM and Chiari II malformation. Nonverbal immediate recall task performance appeared to be related to abnormalities of the fornix.
前瞻性地确定边缘系统神经束的异常情况，并描述在弥散张量磁共振（MR）和纤维束（FT）重建图像上看到的这些异常与脊髓脊膜膨出（MM）和Chiari II型畸形患儿学习与记忆之间的关系。
本研究符合健康保险流通与责任法案（HIPAA）要求，并获得机构审查委员会批准；已获得知情同意。对7名男性和6名女性患者（年龄6个月至16岁）进行了MM和Chiari II型畸形的弥散张量成像和FT重建。FT重建采用分数各向异性连续追踪算法和手动绘制的感兴趣区域。由一位对认知测试结果不知情的经验丰富的儿科神经放射科医生在FT重建图像上评估边缘系统神经束异常情况。9名患者符合由一位对MR结果不知情的训练有素的认知神经科学家进行记忆和学习测试的标准。采用精确威尔科克森秩和检验比较两组在学习和记忆任务中的表现。
13名患者中有11名穹窿和/或扣带回存在缺陷；3名患者有扣带回纤维异常。9名患者中，6名存在一般记忆缺陷；4名存在学习缺陷；4名两者均有缺陷。在6名有记忆缺陷的患者和4名有学习缺陷的患者中发现穹窿脚和体部闭锁或发育不全。6名有记忆缺陷的患者中有5名以及4名有学习缺陷的患者中有3名存在扣带回发育不全或闭锁。精确威尔科克森秩和检验表明，与无穹窿异常的患者相比，有穹窿异常的患者在非言语即时回忆任务中的表现明显较差（P = 0.04，精确双侧检验）。
弥散张量和FT重建图像显示，MM和Chiari II型畸形患者中边缘系统纤维异常很常见。非言语即时回忆任务表现似乎与穹窿异常有关。
