系统讲解 | 非创伤性颅内出血(一)
神经病学医学网 Radiology Assistant
为了方便阅读,我在很多地方进行了汉语注释,希望会有所帮助,满满干货,小板凳搬来,一起学习吧。
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Any type of bleeding inside the skull(颅骨) or brain is a medical emergency.
The most common causes of hemorrhage(出血) are trauma(创伤), haemorrhagic stroke and subarachnoid haemorrhage due to a ruptured aneurysm(动脉瘤破裂).
Complications(并发症) are increased intracerebral pressure as a result of the hemorrhage itself, surrounding edema(水肿) or hydrocephalus(脑积水) due to obstruction of CSF.
In this article we will discuss(讨论) non-traumatic hemorrhages.
They will be discussed by their location, because that is frequently the clue(线索) to the differential diagnosis.
Then we will discuss further imaging to get to a specific(具体的) diagnosis.
Finally specific diseases that present with intracerebral hemorrhages will be presented in more detail(更详细地).
Knowing the location of a hemorrhage is often the key to the differential diagnosis especially in non-traumatic bleeding.
Extra-axial hemorrhage(轴外出血) - Intracranial extracerebral
Subarachnoid hemorrhage(SAH) is acute bleeding under the arachnoid. Most commonly seen in rupture of an aneurysm or as a result of trauma.
Intra-axial hemorrhage(轴内出血) - intracerebral
Lobar hematoma is located in the periphery(边缘) of a lobe. The most common cause is cerebral amyloid angiopathy(CAA), but can also be seen in hypertension, tumor, vascular malformation(畸形), venous infarction(梗死) and many other diseases.
Centrally located hemorrhage in basal ganglia, pons(脑桥) or cerebellum. The most common cause is hypertension(高血压).
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85% of non-traumatic hemorrhages are seen in patients with hypertension or cerebral amyloid angiopathy (CAA).
In hypertension the hemorrhages are typically in a central position in the basal ganglia, pons, thalamus(丘脑) and cerebellum, while in CAA they are typically more in a peripheral location - deep in the frontal(额), parietal(顶) or temporal(颞) lobes - also called lobar hemorrhages(脑叶出血).
The differential diagnosis in a patient with an intracerebral hemorrhage however is much larger and also includes:
Vascular malformations like arteriovenous malformation (AVM), dural arteriovenous fistulas (dAVF), aneurysms(动脉瘤), cavernoma(海绵状血管瘤), DVA (very rare).
Infarction with hemorrhagic transformation
Hemorrhagic venous infarction in sinus thrombosis(静脉窦血栓形成)
Hemorrhagic primary brain tumors or metastases(转移)
Drug abuse
PRESS(可逆性后部脑病综合征)
Reversible cerebral vasoconstriction syndrome(RCVS;可逆性脑血管收缩综合征)
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Lobar hemorrhage(脑叶出血)
Lobar hemorrhages are located in the periphery of the cerebral lobes unlike hypertensive bleeding which usually is located more centrally.
The most common cause especially in elderly is cerebral amyloid angiopathy(CAA), but also hypertension because of its high prevalence(患病率).
Other causes:
Hemorrhagic tumor or metastases
Cavernous malformation
AVM
dAVF
Venous infarction
Here some examples of lobar hemorrhages:
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Right lower image is venous infarction due to sinus thrombosis (yellow arrows)
Bleeding into the ventricular(脑室) system in lobar hemorrhage is not as common as in hypertensive hemorrhage because of the more periferal location.
Only when they are very large, they can cause bleeding into the ventricular system (fig).
This patient died the next day.
No definitive(明确的) diagnosis was made, but it was assumed(考虑) that this was a case of CAA.
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Basal ganglia(基底节)
Hemorrhage in the basal ganglia is typically seen in hypertension.
Hypertensive hemorrhage typically occurs in elderly patients and is usually in a central location.
This differentiates hypertensive bleeding from hemorrhage in patients with cerebral amyloid angiopathy (CAA) which are more peripheral in location, although overlap(重叠) can occur.
The images show a typical hypertensive hemorrhage in the putamen, which is the largest and most lateral part of the basal ganglia.
Continue with the follow up images...
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On a follow up scan only parenchymal(脑实质) loss is seen in the putamen(壳核) where the hemorrhage was located (arrow 下图黄箭头).
The putamen is vascularized by the lenticulostriate arteries (LSa 豆纹动脉).
The LSa are small diameter end vessels that originate at a right angle(直角发出) from the artery of Charcot without the gradual stepdown in size that occurs in the distal cortical(皮层) vessels.
Their(豆纹动脉) internal pressure may be very high and for this reason the LSa are particularly susceptible(受影响) to damage from hypertension, the formation of small aneurysms and rupture (3) (ref).
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The first three images show a large hematoma(血肿) in the basal ganglia on the right with massive edema(水肿明显).
The follow up image one year later shows linear cavitation(线状软化灶) due to tissue loss (arrow) and hypodensity(低密度) of the basal ganglia as a result of gliosis(胶质增生).
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Caudate nucleus(尾状核)
The images show a hemorrhage in the basal ganglia in a patient with longstanding hypertension.
It is located in the head of the caudate nucleus.
The head of the caudate nucleus receives its blood supply from Heubner’s artery and the lenticulostriate arteries(LSa),.
A rupture in these arteries causes parenchymal(实质) hemorrhage.
The presence of an intraventricular haematoma(脑室内出血) is considered a poor prognostic(预后差) factor due to the obstruction to CSF with hydrocephalus(脑积水) and raised intracranial pressure.
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Thalamus(丘脑)
Bleeding in the thalamus is typically seen in hypertension.
This patient presented with hydrocephalus due to an intraventricular hemorrhage (left image).
Note the very small hyperdensity(高密度) in the left thalamus, which is the origin of the hemorrhage(出血的来源).
Follow-up one day later (right image).
The patient underwent surgery with placement of a ventricle drain to treat the hydrocephalus.
Note the hypodense thalamus on the left side with the persistent medially(内侧) located hyperdense focus.
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Cerebellar(小脑)
This patient presented with a cerebellar hemorrhage.
The gradient echo-images(GRE;梯度回波序列) show multiple microbleeds.
This can be the result of long standing hypertension due to the central location of some of the microbleeds.
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Subarachnoid(蛛网膜下腔)
Subarachnoid hemorrhage (SAH) is bleeding in the subarachnoid space between the arachnoid and the pia mater.
The most common cause is trauma(创伤).
Non-traumatic SAH is usually the result of aneurysmal rupture(动脉瘤破裂) with spread of blood into the subarchnoidal cisterns(蛛网膜下池) (fig).
The first choice of imaging modality in a patient with a clinical suspicion(怀疑) of SAH is a non-enhanced CT scan (NECT).
NECT is positive for SAH in 98% within 12 hours of onset.
If the suspicion is strong, but the CT is negative, a lumbar puncture(腰穿) is performed to detect blood in the CSF.
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The images show a subarachnoid hemorrhage as a result of rupture of an aneurysm of the left middle cerebral artery (arrow).
Subarachnoid hemorrhage is discussed in more detail.(第二部分会再讲到)
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Cerebral amyloid angiopathy (CAA;脑淀粉样血管病) is a disorder characterized by deposits of amyloid in the walls of the small leptomeningeal and cortical arteries(柔脑膜和皮质动脉) resulting in leukencephalopathy(白质病变) and hemorrhage.
The hemorrhages can be divided in macrobleeds or lobar hemorrhages, microbleeds and subarachnoid hemorrhages that result in cortical superficial siderosis(cSS;脑皮质表面铁沉积).
It is not associated with systemic amyloidosis(系统性淀粉样变).
The major symptoms are neurologic deficits(神经缺损症状), dementia(痴呆) and epilepsia(癫痫).
The epilepsia is caused by the hemosiderin deposits(含铁血黄素沉积) near the cortex(皮质) of the brain.
The major risk factor is increasing age.
These small hemorrhages are also called microbleeds.
Notice how numerous these small hemorrhages are and primarily located in the perifery of the brain.
This patient presented with a cerebellar hematoma.
Continue with the T1W-image...
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The T1W-image shows a hyperintense hemorrhage (arrow).
Hypertensive intracranial haemorrhage together with CAA make up 80% of the causes of intraparenchymal hematomas(脑实质出血).
Think of CAA(要考虑到CAA) if you see multiple peripheral or lobar haemorrhages in an elderly patient.
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Dutch type of hereditary CAA(荷兰型遗传性CAA)
The Dutch type of hereditary cerebral amyloid angiopathy is the most common form(最常见的类型).
Stroke is frequently the first sign(首发症状) of the Dutch type and is fatal in about one third of people who have this condition.
Survivors often develop dementia and have recurrent strokes.
About half of individuals(大约一半的人) with the Dutch type who have one or more strokes will have recurrent seizures(癫痫发作).
Cortical superficial siderosis in CAA
CAA-related bleeds include:
Macrobleeds - symptomatic(有症状的) lobar hemorrhages
Microbleeds - small and typically silent peripherally located
Cortical superficial siderosis (cSS) - cortical subarachnoid hemorrhages that follow the curvilinear shape(曲线样) of the surrounding cerebral gyri
In superficial siderosis the proximity(临近) to the cortical surface appears to be(好像是) the trigger(诱因) for transient focal neurologic symptoms(短暂性局灶性神经系统发作) or amyloid spells(脑淀粉样发作).
CAA patients with widespread cortical superficial siderosis have a far greater chance for recurrent hemorrhage compared to patients without cSS.
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Lobar hemorrhage in Cerebral Amyloid angiopathy (CAA)
This patient with CAA presented with a large lobar hematoma in the right temporal lobe.
Notice the superficial siderosis (arrow).
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This patient with CAA has microbleeds, superficial siderosis and multiple infarcts(梗死).
Notice the hemorrhage in the pons(脑桥) (yellow arrow).
There is superficial siderosis in the left occipital region(枕部).
The DWI shows infarction in left occipital lobe and right frontal lobe (with some artifacts;伴伪影).
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第二部分待续......
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