# 髓鞘内水肿（Intramyelinic Edema）

- 器官 / 系统：脑 / 神经系统（brain / nervous-system）
- NTP 数据编号：ntp-0399
- 规范 URL：https://www.labsmart.cn/ntp/brain-intramyelinic-edema.html
- 中文图谱总页锚点：https://www.labsmart.cn/ntp-atlas.html#brain-intramyelinic-edema
- 原始出处：https://ntp.niehs.nih.gov/atlas/nnl/nervous-system/brain/IntramyelinicEdema
- 授权：美国联邦政府作品，公有领域；引用请标注 NTP Nonneoplastic Lesion Atlas
- 适用说明：仅供科研使用，不用于临床诊断

## 一句话结论
白质的“海绵状”（sponginess）（Figure 4，箭头）表现始终是神经病理学家关注的问题，因为它通常是固定不良和自溶的伪影。

## 病变描述（中文）
白质的“海绵状”（sponginess）（Figure 4，箭头）表现始终是神经病理学家关注的问题，因为它通常是固定不良和自溶的伪影。Figure 1、Figure 2 显示了大鼠小脑白质中髓鞘经Luxol fast blue和cresyl violet染色后的正常形态。评估组织是否存在固定不良和自溶的指标，对于判定真正的白质病变极为重要。真正的白质病变如脱髓鞘（demyelination）具有一些有用的真实性标志（见脊髓-脱髓鞘），如双侧对称性以及受累区域存在肿胀的轴突或巨噬细胞。其他白质病变如髓鞘内水肿（intramyelinic edema）表现为白质严重的海绵状改变，而无任何髓鞘破坏或细胞反应的证据。典型情况下，髓鞘内水肿由亲脂性化合物引起，导致髓鞘板层在周期内线（intraperiod line）处分离（经电子显微镜证实）。在中枢神经系统中，这是由于少突胶质细胞胞质内液体积聚所致。对此类白质病变研究较为充分的例子包括六氯酚（hexachlorophene）暴露，如Figure 3、Figure 4 所示。慢性六氯酚暴露还可产生星形细胞肥大和增生，如胶质纤维酸性蛋白免疫组化染色所示。已证明停止六氯酚暴露可使大鼠的临床和镜下海绵状效应逆转。

## 诊断与分级建议（NTP 共识，中文）
在NTP研究中，当光镜下无法将髓鞘内水肿与脱髓鞘或轴突病（axonopathy）区分时，该病变应诊断为白质空泡化（white matter vacuolation）。随后应由神经病理学家进行特殊评估。在怀疑髓鞘内水肿的情况下，通常不存在轴突病和炎症反应，仅对固定良好的材料进行电子显微镜检查可能具有确诊作用。在NTP研究中出现时，应注明亚部位并对病变严重程度进行分级。

## 英文原文 · Comment
The presence of “sponginess” ( Figure 4 , arrow) of the white matter is always of concern to the neuropathologist since it is commonly an artifact of poor fixation and autolysis. Figure 1 and Figure 2 show the normal appearance of myelin in rat cerebellar white matter stained with Luxol fast blue and cresyl violet. Assessment of the tissue for indicators of poor fixation and autolysis is extremely important to determine genuine white matter lesions. Valid white matter lesions such as demyelination have some useful hallmarks of authenticity (see Spinal Cord - Demyelination ), such as bilateral symmetry and the presence of swollen axons or macrophages in affected areas. Other white matter lesions such as intramyelinic edema are observed as severe spongiform change of white matter without any evidence of myelin breakdown or cellular reaction. Classically, intramyelinic edema is caused by lipophilic compounds that result in separation of myelin lamellae at the intraperiod line (confirmed by electron microscopy). In the CNS, this is due to the accumulation of fluid in the cytoplasm of oligodendroglial cells. Well-studied examples of this form of white matter lesion include exposure to hexachlorophene, as shown in Figure 3 and Figure 4 . Chronic exposure to hexachlorophene also produces astrocytic hypertrophy and proliferation, as demonstrated by glial fibrillary acid protein immunohistochemical staining. Removal of hexachlorophene exposure has been shown to lead to a reversal of the clinical and microscopic spongiform effects in rats.

## 英文原文 · Recommendation
In NTP studies where intramyelinic edema cannot be differentiated from demyelination or axonopathy under light microscopy, the lesion should be diagnosed as white matter vacuolation. This should be followed by special evaluation by a neuropathologist. In the case of suspected intramyelinic edema, where axonopathy and inflammatory responses are generally absent, examination of only well-fixed material by electron microscopy may be confirmatory. When present in NTP studies, the subsite should be noted and lesion severity graded.

## 配图
- https://www.labsmart.cn/ntp-atlas-images/ntp_0567.jpg
- https://www.labsmart.cn/ntp-atlas-images/ntp_0571.jpg

整理：北京天融慧通科技有限责任公司（LabSmart）｜ https://www.labsmart.cn