腦疝分類及影像學(xué)表現(xiàn)圖解

1、圖解腦疝杜萬良（reflexhammer）腦疝n是指在顱內(nèi)壓增高的情況下，腦組織通過某些腦池向壓力相對較低的部位移位的結(jié)果，即腦組織由其原來正常的位置而進入了一個異常的位置。腦疝的類型：na.大腦鐮疝 ： 一側(cè)大腦半球占位病變可使同側(cè)扣帶回經(jīng)大腦鐮下緣疝入對側(cè)，胼胝體受壓下移。 n小腦幕切跡疝 b.前疝：也稱顳葉溝回疝，是顳葉溝回疝于腳間池及環(huán)池的前部；后疝：顳葉內(nèi)側(cè)部疝于四疊體池及環(huán)池的后部；f.小腦幕切跡上疝：后顱凹占位病變時，小腦上蚓部可向上疝入小腦幕切跡的四疊體池。nc.中心疝：幕上壓力增高，致使大腦深部結(jié)構(gòu)及腦干縱軸牽張移位。 nd.顱外疝： 腦組織通過顱外缺損疝出。ne.枕骨大孔疝

2、 ： 后顱凹占位病變時，可致小腦扁桃體疝入枕骨大孔。ng.蝶骨嵴疝：顱前凹和顱中凹的占位病變，由于病變部壓力相對高一些，則額眶回可越過蝶骨嵴進入顱中凹，可顳葉前部擠向顱前凹。示意圖na) subfalcial (cingulate) herniation ;鐮下疝nb) uncal herniation ; 鉤疝nc) downward (central, transtentorial) herniation ; 下行性小腦幕疝nd) external herniation ; 顱外疝ne) tonsillar herniation.扁桃體疝nf) ascending transtentori

3、al herniation (reversed tentorial)上行性小腦幕疝ng) sphenoid herniation蝶骨嵴疝類型示意圖解剖關(guān)系解剖關(guān)系FQcMb3vTOSyCClvFPOSpCClvss解剖關(guān)系FTCesPd4th VFTMbCesThe suprasellar cistern & the quadrigeminal cisternnThe left and center images show the suprasellar cistern. Its anterior borders are formed by the frontal lobes (F).

4、 Its lateral borders are formed by the uncus (U) of the temporal lobes. The left image shows the 5-pointed star appearance of the suprasellar cistern where the posterior border is formed by the pons (Po). The black arrow points to the fourth ventricle. The center image shows a higher cut where the s

5、uprasellar cistern has a 6-pointed star appearance since the posterior border is formed by the cerebral peduncles (P) which have a central cleft. nThe right image shows the quadrigeminal cistern (black arrow). Note the babys bottom appearance of its anterior border. When ICP is increased, the quadri

6、geminal cistern space is compressed or obliterated. The suprasellar cistern& the quadrigeminal cistern. nThe midline sagittal MRI scan shows the levels of the axial diagrams. The quadrigeminal cistern is located above (anterior to) the Q in the highest cut shown (number 9). The anterior border o

7、f the quadrigeminal cistern is formed by the superior colliculi (c). Image 8 (lower cut) also shows the quadrigeminal cistern. In this case, its anterior border is formed by the inferior colliculi (c). This gives the anterior border of the quadrigeminal cistern the appearance of a babys bottom. The

8、quadrigeminal plate is comprised of the superior and inferior colliculi. The quadrigeminal cistern is posterior to this quadrigeminal plate, thus its anterior border may be formed by the inferior or superior colliculi. 鐮下疝臨床表現(xiàn)影像所見并發(fā)癥頭痛對側(cè)下肢無力同側(cè)額角截斷大腦鐮前份不對稱同側(cè)側(cè)腦室腔消失透明隔移位因大腦前動脈卡壓到大腦鐮上引起同側(cè)ACA供血區(qū)梗塞伴有其他疝Su

9、bfalcine herniation (cingulate herniation)Transtentorial herniation nThe suprasellar cistern (left image) is obliterated. The quadrigeminal cistern is very compressed and pushed posteriorly (center image). nA subdural hematoma with a midline shift is noted. There is central transtentorial and subfal

10、cine herniation.ACA供血區(qū)梗塞Uncal herniation臨床表現(xiàn)影像所見并發(fā)癥同側(cè)瞳孔散大、眼動受限（動眼神經(jīng)受壓）對側(cè)偏癱（同側(cè)大腦腳受壓）有時顳葉疝壓跡會導(dǎo)致同側(cè)偏癱（對側(cè)大腦腳受壓。假定位體征）對側(cè)顳角增寬同側(cè)環(huán)池增寬同側(cè)橋前池增寬鉤回進入鞍上池大腦后動脈受壓導(dǎo)致枕葉梗塞鞍上池缺角冠狀位CT與MRI海馬旁回褶皺對側(cè)顳角增寬同側(cè)橋前池增寬同側(cè)環(huán)池增寬Uncal herniationUncal herniationnobliteration of the suprasellar cistern (red arrow) and the quadrigeminal cis

11、tern (green arrow)Uncal herniationnThe ipsilateral ventricle, sulci, fissures are compressed and obliterated, isappeared.nobliteration of the suprasellar cistern(s) and quadrigeminal cistern(q)Uncal herniationnAcute infarctionn1st daynAcute infarction n4th daysqUncal herniationnBefore surgery, a big

12、 GBM in the left temporal lobe with uncal herniation.nAfter surgery, the GBM was removed, the suprasellar cistern and quadrigeminal cisterns are normal.Uncal herniationnAcute infarction of right posterior artery (PCA), this is a complication of uncal/transtentorial herniation, because the PCA was co

13、mpressed by brain herniation.雙側(cè)大腦后動脈梗塞雙側(cè)大腦后動脈梗塞Durette hemorrhage Durette hemorrhageKernohans notch顳葉疝壓跡Uncal herniationnWhen mass effects within or adjacent to the temporal lobe occur, the medial portion of the temporal lobe (uncus) is forced medially and downward over the tentorium. There is ipsil

14、ateral pupillary dilation. The uncus is pushed medially into the suprasellar cistern. There is bilateral uncal herniation. The suprasellar cistern is obliterated.early uncal herniation nThe right uncus is pushing into the suprasellar cistern; early right uncal herniation. 中心疝中心疝Superior vermian hern

15、iation ( ascending transtentorial herniation )n由于后顱凹的占位效應(yīng)，小腦蚓和小腦半球通過小腦幕切跡向上移動臨床表現(xiàn)影像所見并發(fā)癥惡心嘔吐意識障礙中腦外觀呈陀螺狀雙側(cè)環(huán)池變窄四疊體池充滿因小腦上動脈受壓引起梗塞Galen靜脈移位腦積水意識障礙迅速出現(xiàn)，并可能死亡陀螺狀外觀雙側(cè)環(huán)池變窄四疊體池充滿不露齒的微笑皺眉第一天的四疊體池和環(huán)池第二天，四疊體池和環(huán)池消失腦積水a(chǎn)scending transtentorial herniation枕大孔疝臨床表現(xiàn)影像所見并發(fā)癥雙側(cè)上肢感覺減退意識障礙軸位像見到小腦扁桃體位于齒狀突水平矢狀位見到小腦扁桃體低于枕大孔

16、5mm（成人）或7mm（兒童）小腦扁桃體出血性壞死意識障礙和死亡枕大孔疝Tonsillar herniation nIn tonsillar herniation (rare), a mass effect in the posterior fossa causes the cerebellar tonsils to herniate inferiorly through the foramen magnum compressing the medulla and upper cervical spinal cord. Conscious patients complain of neck p

17、ain and vomiting. They may have nystagmus, pupillary dilatation, bradycardia, hypertension and respiratory depression. Early tonsillar herniation is difficult to recognize in an unconscious patient. It may not be evident on CT scan since axial views cannot see the pathology well. It is best seen on

18、sagittal MRI. Clinically changes in vital signs may be the only clinical clue in an unconscious patient.Tonsillar herniationa male patient in his 30s who died of brain stem herniation after completing a marathon. nThe CT shows (A) loss of the rostral cerebral sulci suggesting increase in ICP, (B) an

19、d (C) a large hydrocephalus with widening of both temporal horns. The grey matter can still be differentiated from the white matter, but all sulci are lost. This suggests that the brain oedema is of relative recent onset and massive tissue ischaemia has not yet occurred. (D) Compression of the fourt

20、h ventricle with dilatation of the third ventricle and the caudal aspect of both temporal horns. This is observed with considerable brain oedema and obstructive hydrocephalus. (E) Herniation of the medulla and pons into the foramen magnum. (F) The tonsils are located at the level of the dens which i

21、s a good indicator for foramen magnum herniation.n(A) The disc shows florid hemorrhages with relatively little swelling, indicating a rapid, dramatic increase in CSF pressure. Progressive changes of optic disc oedema are seen in a patient with an intracranial tumour who declined treatment (B-D). (B)

22、 Early nerve fiber dilatation is seen particularly superiorly, inferiorly and nasally. (C) This increases and venous engorgement develops. (D) Temporal nerve fiber dilatation and swelling of the disc increases and hemorrhages appear. (E) In gross chronic disc oedema the normal retinal vasculature is masked and dilated superficial capillaries are observed. (F) In atrophic optic disc oedema nerve fibers