Children's Hospital, Toulouse-Purpan University Hospital, Toulouse, France; ToNIC, Toulouse NeuroImaging Center, University of Toulouse, Inserm, UPS, France.
ToNIC, Toulouse NeuroImaging Center, University of Toulouse, Inserm, UPS, France.
Eur J Paediatr Neurol. 2020 Sep;28:89-100. doi: 10.1016/j.ejpn.2020.07.003. Epub 2020 Jul 31.
NF1 children have cognitive disorders, especially in executive functions, visuospatial, and language domains, the pathophysiological mechanisms of which are still poorly understood.
A correlation study was performed from neuropsychological assessments and brain MRIs of 38 NF1 patients and 42 controls, all right-handed, aged 8-12 years and matched in age and gender. The most discriminating neuropsychological tests were selected to assess their visuospatial, metaphonological and visuospatial working memory abilities. The MRI analyses focused on the presence and location of Unidentified Bright Objects (UBOs) (1), volume analysis (2) and diffusion analysis (fractional anisotropy and mean diffusivity) (3) of the regions of interest including subcortical structures and posterior fossa, as well as shape analysis of subcortical structures (4). The level of attention, intelligence quotient, age and gender of the patients were taken into account in the statistical analysis. Then, we studied how diffusion and volumes parameters were associated with neuropsychological characteristics in NF1 children.
NF1 children present different brain imaging characteristics compared to the control such as (1) UBOs in 68%, (2) enlarged total intracranial volume, involving all subcortical structures, especially thalamus, (3) increased MD and decreased FA in thalamus, corpus callosum and hippocampus. These alterations are diffuse, without shape involvement. In NF1 group, brain microstructure is all the more altered that volumes are enlarged. However, we fail to find a link between these brain characteristics and neurocognitive scores.
While NF1 patients have obvious pathological brain characteristics, the neuronal substrates of their cognitive deficits are still not fully understood, perhaps due to complex and multiple pathophysiological mechanisms underlying this disorder, as suggested by the heterogeneity observed in our study. However, our results are compatible with an interpretation of NF1 as a diffuse white matter disease.
NF1 患儿存在认知障碍，特别是在执行功能、视空间和语言领域，其病理生理机制仍知之甚少。
对 38 名 NF1 患者和 42 名对照组（均为右利手，年龄 8-12 岁，年龄和性别匹配）的神经心理学评估和脑部 MRI 进行了相关性研究。选择最具鉴别力的神经心理学测试来评估他们的视空间、音韵和视空间工作记忆能力。MRI 分析侧重于不明亮物体（UBO）（1）的存在和位置、体积分析（2）和感兴趣区域的扩散分析（各向异性分数和平均弥散度）（3），包括皮质下结构和后颅窝，以及皮质下结构的形状分析（4）。在统计分析中考虑了患者的注意力水平、智商、年龄和性别。然后，我们研究了 NF1 患儿的扩散和体积参数如何与神经心理学特征相关。
与对照组相比，NF1 患儿存在不同的脑部影像学特征，包括（1）68%存在 UBO，（2）总颅内体积增大，涉及所有皮质下结构，特别是丘脑，（3）丘脑、胼胝体和海马的 MD 增加和 FA 降低。这些改变是弥漫性的，没有形状参与。在 NF1 组中，脑微结构改变越大，体积增大越明显。然而，我们未能发现这些脑特征与神经认知评分之间的联系。
虽然 NF1 患者存在明显的病理性脑特征，但他们认知缺陷的神经元基础仍未完全阐明，这也许是由于该疾病的病理生理机制复杂多样，正如我们研究中观察到的异质性所表明的那样。然而，我们的结果与将 NF1 解释为弥漫性白质疾病的观点一致。
