Tsai Chia-Chen, Combes Anna, McMullen Katrina, Kolind Shannon H, Traboulsee Anthony L
Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
Department of Neuroinflammation, NMR Research Unit, Queen Square Multiple Sclerosis Centre, University College London, London, UK.
J Neuroimaging. 2025 Jan-Feb;35(1):e13250. doi: 10.1111/jon.13250. Epub 2024 Nov 7.
Neuromyelitis optica spectrum disorder (NMOSD) affects the optic nerves and spinal cord but can also cause focal brain inflammation. Subcortical pathology may contribute to the etiology of cognitive deficits in NMOSD. Using myelin water imaging, we investigated cerebral normal-appearing white matter (NAWM) and thalamic metrics and their association with cognition in NMOSD participants compared to healthy controls (HC).
Seventeen NMOSD participants and 21 HC were scanned on a 3.0-Tesla MRI scanner using a multicomponent driven-equilibrium single-pulse observation of T and T protocol. Tissue compartment and thalamic volumes (normalized to intracranial volume), T relaxation time, and myelin water fraction (MWF) were reported. Eleven NMOSD participants underwent the Symbol Digit Modalities Test (SDMT) for cognitive evaluation. Group comparisons were performed using Student's t-test. The association between thalamic metrics and SDMT score was assessed using multiple regression analysis with age as a covariate.
Compared to HC, NMOSD participants had reduced white matter volume (-14.2%, p < .0001), increased T relaxation time (+2.29%, p = .022), and lower MWF (-3.64%, p = .024) in NAWM. NMOSD group had a trend for smaller thalamic volumes than HC (-5.52%, p = .082) and no differences in thalamic MWF (p = .258) or T (p = .714). Thalamic T predicted SDMT score (adjusted R = .51, p = .04) when controlling for age.
NAWM in NMOSD demonstrates diffuse abnormalities with increased water content and demyelination, suggesting a diffuse disease process overlooked by focal inflammation measures. Increased water content, as a biomarker for diffuse thalamic pathology, may partially explain cognitive impairment in NMOSD.
视神经脊髓炎谱系障碍（NMOSD）会影响视神经和脊髓，但也可导致局灶性脑炎症。皮质下病理改变可能是NMOSD认知缺陷病因的一部分。我们使用髓鞘水成像技术，研究了NMOSD参与者与健康对照（HC）相比，脑内正常表现白质（NAWM）和丘脑指标及其与认知的关系。
17名NMOSD参与者和21名HC在3.0特斯拉MRI扫描仪上进行扫描，采用多成分驱动平衡单脉冲观察T和T协议。报告组织成分和丘脑体积（标准化为颅内体积）、T弛豫时间和髓鞘水分数（MWF）。11名NMOSD参与者接受符号数字模态测试（SDMT）进行认知评估。采用学生t检验进行组间比较。以年龄作为协变量，使用多元回归分析评估丘脑指标与SDMT评分之间的关联。
与HC相比，NMOSD参与者的NAWM白质体积减少（-14.2%，p <.0001），T弛豫时间增加（+2.29%，p =.022），MWF降低（-3.64%，p =.024）。NMOSD组丘脑体积比HC有减小趋势（-5.52%，p =.082），丘脑MWF（p =.258）或T（p =.714）无差异。在控制年龄时，丘脑T预测SDMT评分（调整后R =.51，p =.04）。
NMOSD中的NAWM表现出弥漫性异常，含水量增加和脱髓鞘，提示局灶性炎症测量可能忽略的弥漫性疾病过程。含水量增加作为弥漫性丘脑病理的生物标志物，可能部分解释NMOSD中的认知障碍。
