双语病例——假性蛛网膜下腔出血
朗读老师：温满盈-东莞市大朗医院放射科
History: A 51-year-old man was found down and without a pulse. He required 30 minutes of advanced cardiovascular life support (ACLS) before return of spontaneous circulation (ROSC). Urine drug screen (UDS) was positive for opioids.
病史：一名 51 岁男子发现时昏倒，无脉搏。在恢复自主循环 (ROSC) 前进行了 30 分钟的高级生命支持 (ACLS)。尿检显示阿片类药物阳性。
Findings
CT: Diffuse cerebral edema with brain hypoattenuation, indistinctness of the basal ganglia bilaterally, diffuse sulcal effacement, and hyperdense appearance of the subarachnoid spaces relative to adjacent brain parenchyma
MRI: No intracranial hemorrhage on GRE sequence
CT：弥漫性脑水肿伴脑实质密度减低，双侧基底节区模糊，弥漫性脑沟消失，蛛网膜下腔相对于邻近脑实质呈高密度。
MRI：GRE序列示无颅内出血
Differential diagnosis
Subarachnoid hemorrhage
Toxic metabolic injury
Severe meningitis
Intrathecal contrast
Venous thrombosis
Diagnosis: Pseudosubarachnoid hemorrhage secondary to global hypoxic injury following cardiac arrest
鉴别诊断
蛛网膜下腔出血
中毒性代谢损伤
严重脑膜炎
造影剂鞘内注射
静脉血栓形成
诊断： 心脏骤停后继发于全身缺氧性损伤的假性蛛网膜下腔出血
Pseudosubarachnoid hemorrhage
假性蛛网膜下腔出血
Pathophysiology
Anything that causes diffuse cerebral edema will cause the brain parenchyma to decrease in attenuation. This will make the attenuation of the basal cisterns appear increased giving the appearance of hemorrhage. Causes of diffuse cerebral edema include anoxic injury after cardiac arrest and venous thrombosis. Other causes of increased cerebrospinal fluid (CSF) attenuation include meningitis with blood-brain barrier breakdown and leakage of protein into the CSF, as well as prior administration of intrathecal contrast.
病理生理学
任何引起弥漫性脑水肿的因素都会导致脑实质密度减低。这将使基底池的密度相对增加，类似于出血表现。弥漫性脑水肿的原因包括心脏骤停后的缺氧性损伤和静脉血栓形成。脑脊液 (CSF) 密度增加的其他原因包括脑膜炎伴血脑屏障破坏和蛋白质渗漏到 CSF 中，以及先前造影剂鞘内注射。
Epidemiology
Small case reports suggest up to 8% of patients with diffuse cerebral edema may show this sign, often in the setting of an unwitnessed cardiac arrest.
流行病学
案例报道示多达 8% 的弥漫性脑水肿患者可能会出现这种征象，通常是在没有目击患者心脏骤停的情况下。
Clinical presentation
Most patients will present with altered mental status or are unresponsive due to the underlying severe diffuse cerebral edema.
临床表现
由于存在严重弥漫性脑水肿，大多数患者会出现精神状态改变或反应迟钝。
Imaging features
CT: Symmetric density within the basal cisterns, which is increased in attenuation but not definitive for blood in the setting of diffuse cerebral edema
MR: Evidence of edema; however, no blooming artifact on GRE/susceptibility-weighted imaging (SWI) sequences as there is no hemorrhage
Treatment
影像特点
CT：在弥漫性脑水肿的情况下，基底池密度对称性增加，但不能确定为出血。
MR：显示为脑水肿；然而，由于无出血，GRE或 SWI)序列上并没有晕状伪影。
It is important to differentiate hemorrhage from pseudohemorrhage as therapeutic hypothermia is contraindictated in the setting of intracranial hemorrhage. Lumbar puncture should be used for definitive diagnosis, especially in patients not stable enough to get an MRI. Treatment of the underlying condition is paramount.
治疗
区分出血与假性出血很重要，因为低温治疗在颅内出血的情况下是禁忌的。腰椎穿刺应用于明确诊断，尤其是对于病情不够稳定无法进行 MRI 的患者。治疗基础疾病最重要。