Aoyama Takeshi, Ohtaki Masafumi, Nomura Tatsufumi, Chiba Masahiko
Department of Neurosurgery, Obihiro Kosei General Hospital, Nishi 6 Minami 8, Obihiro, Hokkaido, Japan.
No Shinkei Geka. 2007 Mar;35(3):283-8.
Calcified carotid plaques are thought to be less likely to be symptomatic than non-calcified plaques. We present a patient with an unusual cerebral embolism that appeared as very high density on CT and was ascertained to derive from a calcified plaque. This 46-year-old male was admitted within 1 hr of sudden aphasia onset. The admission CT scan showed multiple high-intensity lesions that appeared like calcification. They were high intensity on MRI FLAIR images. MRA showed occlusion of the posterior trunk of the middle cerebral artery. As we considered cerebral embolism, the patient received heparin followed by warfarin. Routine MRA and DSA detected no abnormality, however, a carotid echogram showed a hyperechoic plaque at the left carotid bifurcation. As the NASCET method indicated 6.5% stenosis, carotid endarterectomy was not indicated. However, the thrombus at the bifurcation gradually enlarged despite adequate medical treatment (PT-INR 2.2 - 2.7) and we decided to surgically remove the calcified plaque, thought to be the embolus source. We removed the plaque content through a defect in the plaque membrane. Intraoperatively we found that the rapidly enlarging lesion was the plaque content rather than a thrombus. Pathologically, calcification was more dominant than atherosclerosis. His postoperative course was good and he required only aspirin. This case was peculiar in that the calcification mimicked a hyperdensity embolus and that the lesion derived from a calcified plaque which is usually stable. Repeat carotid ultrasonography is easy and useful when routine investigation fails to reveal the embolic source.
钙化的颈动脉斑块被认为比非钙化斑块引起症状的可能性更小。我们报告一例患有罕见脑栓塞的患者，其在CT上表现为极高密度影，经确定栓子来源于一个钙化斑块。这名46岁男性在突发失语症后1小时内入院。入院时的CT扫描显示多个高密度病灶，看似钙化。在MRI FLAIR图像上它们呈高强度信号。MRA显示大脑中动脉后干闭塞。由于我们考虑为脑栓塞，患者接受了肝素治疗，随后使用华法林。常规MRA和DSA未检测到异常，然而，颈动脉超声检查显示左颈动脉分叉处有一个高回声斑块。根据北美症状性颈动脉内膜切除术试验（NASCET）方法，狭窄率为6.5%，因此未行颈动脉内膜切除术。然而，尽管进行了充分的药物治疗（PT-INR为2.2 - 2.7），分叉处的血栓仍逐渐增大，于是我们决定手术切除被认为是栓子来源的钙化斑块。我们通过斑块包膜上的一个缺损清除了斑块内容物。术中我们发现迅速增大的病灶是斑块内容物而非血栓。病理检查显示，钙化比动脉粥样硬化更为明显。他术后恢复良好，仅需服用阿司匹林。该病例的特殊之处在于钙化表现类似高密度栓子，且病灶来源于通常较为稳定的钙化斑块。当常规检查未能发现栓子来源时，重复进行颈动脉超声检查简便且有用。
