脑白质病变..docxVIP

1.??中毒性：2.??遗传性：3.??脱髓鞘：4.??感染性：5.??代谢紊乱：6.??血管性：7.??肿瘤性：8.??脑积水：第一章：中毒性heroin vapor inhalation toxicity (海洛因吸入中毒)：病因与病理：不纯海洛因放在铝箔上加热，可能产生了某种神经毒性物质。使受累脑白质产生海绵状变性（spongiform degeneration）。治疗：对症支持，辅酶Q及维生素可能有效。影像学：Involvement of the cerebellum and the posterior limb of the internal capsule, with sparing of the anterior limb, appears to be a characteristic finding in this condition, helping to distinguish it from other causes of leukoencephalopathy such as toluene toxicity or reversible posterior leukoencephalopathy.第一例：参考文献：Neuroimaging Features of Heroin Inhalation Toxicity: Chasing the Dragon （ AJR 2003; 180:847-850）第二例:参考文献同第一例。可以看出和第一例有类似的影像学特静脉应用海洛因和cocaine(可卡因)中毒男性37岁病人，但是他几乎完全恢复了。参考文献：Toxic leukoencephalopathy after intravenous consumption of heroin and cocaine with unexpected clinical recovery （ J Neurol (1999) 246 :850–851）慢性甲苯（Toluene, or methylbenzene）吸入中毒：甲苯是一种脂溶性芳香族碳氢化物，作为一种有机溶剂广泛运用于工业中，稀释剂、粘合剂、喷雾剂、涂漆等中都含有它。长期吸入甲苯后，经肺进入血液循环，通过亲脂的血脑屏障，从而对脑产生损害。影像特点：可先出现侧脑室旁的白质病变，再累及半卵园中心皮层下的白质，若接触时间更长（平均8.1年），可出现丘脑对称性T2低信号。（The focal preservation of gray matter-white matter differentiation in the subcortical white matter in our patients with diffuse changes indicates that white matter changes start in the periventricular area and then extend into the subcortical white matter.），但丘脑对称性T2低信号机制尚不明：继发于脱髓鞘和轴突丢失的铁沉积是最可能的机制。（The deposition of iron caused by demyelination and axonal loss seems to be the most probable mechanism for thalamic hypointensity on T2-weighted images in toluene-containing solvent abuse.）参考文献：Cranial MR Findings in Chronic Toluene Abuse by Inhalation（American Journal of Neuroradiology 23:1173-1179, August 2002）接触甲苯3年： A and B, Bilateral, symmetric hyperintensity is present in the parietal periventricular white matter (arrowheads). Note that gray matter-white matter differentiation is preserved. The widths of the cerebral sulci are normal. A suggests that the hyperintense findings may be caused by terminal myelination, which is a normal MR imaging finding in c