Hyman Shelley L, Gill Deepak S, Shores Edwin Arthur, Steinberg Adam, North Kathryn N
Neurogenetics Research Unit at the Children's Hospital at Westmead, Discipline of Paediatrics and Child Health Faculty of Medicine, University of Sydney, Sydney, Australia.
J Neurol Neurosurg Psychiatry. 2007 Oct;78(10):1088-91. doi: 10.1136/jnnp.2006.108134. Epub 2007 Feb 13.
Neurofibromatosis type 1 (NF1) is a single gene disorder associated with a high frequency of cognitive deficits and a complex cognitive phenotype. These cognitive deficits have been associated with focal areas of high signal intensity on T2 weighted MRI images but the relationship remains controversial.
A cohort of 76 children with NF1 and 45 unaffected sibling controls (aged 8-16 years) underwent extensive neuropsychological assessment, with the NF1 children having MRI examinations.
The presence or number of T2 hyperintensities (T2H) was not associated with cognitive dysfunction. However, the location of discrete (well circumscribed) T2H in the thalamus was associated with severe and generalised cognitive impairment. More diffuse lesions in the thalamus were also associated with reductions in IQ but the effects were less marked compared with the discrete lesions. Comparing children with NF1 to their unaffected siblings revealed more subtle effects of the lesions on cognitive ability.
T2H cannot be used in general as a radiological marker for cognitive deficits in children with NF1; however, lesions in the thalamus are strongly associated with cognitive impairment. It is possible that lesions in the thalamus in conjunction with more general thalamic hypometabolism may compound the level of thalamic dysfunction, resulting in cognitive deficits well beyond those produced by T2H in other regions.
1型神经纤维瘤病（NF1）是一种单基因疾病，与高频率的认知缺陷和复杂的认知表型相关。这些认知缺陷与T2加权MRI图像上的高信号强度局灶性区域有关，但这种关系仍存在争议。
对76名NF1儿童和45名未受影响的同胞对照（年龄8 - 16岁）进行了广泛的神经心理学评估，NF1儿童接受了MRI检查。
T2高信号（T2H）的存在或数量与认知功能障碍无关。然而，丘脑离散性（边界清晰）T2H的位置与严重的全身性认知障碍有关。丘脑中更弥漫性的病变也与智商降低有关，但与离散性病变相比，影响较小。将NF1儿童与其未受影响的同胞进行比较，发现病变对认知能力的影响更为细微。
T2H一般不能用作NF1儿童认知缺陷的影像学标志物；然而，丘脑病变与认知障碍密切相关。丘脑中的病变可能与更普遍的丘脑代谢减低共同作用，加重丘脑功能障碍的程度，导致认知缺陷远超其他区域T2H所产生的影响。
