Extracranial distal aneurysm of posterior inferior cerebellar artery

An unusual aneurysm arising from an extracranial lateral medullary segment of the posterior inferior cerebellar artery (PICA) is reported. The origin of the PICA was also extracranial, 10 mm below the foramen magnum. The aneurysm was not seen on three-vessel angiography. The literature is reviewed with regard to the clinical and radiological features of such aneurysms. Occipital and nuchal headache with an altered level of consciousness, intraventricular haemorrhage, and hydrocephalus are suggestive of such aneurysm. The need for four-vessel angiography is again stressed. Received: 30 April 1996 Accepted: 26 July 1996     

Isolated dissecting aneurysm of the left posterior inferior cerebellar artery: endovascular treatment with a Guglielmi detachable coil.

An isolated progressive dissecting aneurysm of the left posterior inferior cerebellar artery (PICA) associated with a persistent trigeminal artery was successfully treated by endovascular occlusion of the proximal PICA with a Guglielmi detachable coil.     

Stent implantation in a patient with non-hemorrhagic vertebral artery dissection associated with severe,continuously progressive stenosis in the posterior inferior cerebellar artery bifurcation region: A case report

Generally, the prognosis of non-hemorrhagic vertebral artery dissection is good. Treatment should be considered when stenosis progresses or when an aneurysm is formed. However, no clear treatment policy has been established. The purpose of this case report was to describe the treatment policy for non-hemorrhagic onset vertebral artery dissection with severe stenosis around the posterior inferior cerebellar artery (PICA) bifurcation and aneurysm, where stent placement in the vertebral artery was difficult. This report describes healing without complications with stent implantation in the PICA performed to treat non-hemorrhagic vertebral artery dissection with associated severe, continuously progressive stenosis in the PICA bifurcation region. A 36-year-old woman was examined at the authors’ hospital for persistent pain in the left posterior neck. Left vertebral arteriography revealed stenosis due to dissection around the PICA bifurcation and aneurysm formation at the distal position. Due to the progression of stenosis, there were concerns about PICA occlusion, and stent implantation in the vertebral artery was performed via the PICA. Neck pain ceased immediately after surgery, and 3 months later, cerebral angiography showed favorable patency of the PICA and decreased aneurysm size. This case suggests that stent implantation in the PICA might be a useful treatment option for non-hemorrhagic vertebral artery dissection with associated severe stenosis in the PICA bifurcation region.     

Endovascular treatment of isolated dissecting aneurysm of the posterior inferior cerebellar artery

BACKGROUND AND PURPOSE: Isolated dissecting aneurysms of the posterior inferior cerebellar artery (PICA) carry a high risk of rebleeding with an associated increased mortality rate. Although rare, they present a therapeutic challenge. Surgical treatment carries a significant risk of neurologic complications, predominantly lower cranial nerve deficits because of the close relationship of the aneurysm with the brain stem and cranial nerves. The purpose of this article is to show that endovascular treatment of dissecting aneurysms of the PICA can be effective and can allow the patient to avoid the complications associated with surgery. METHODS: Six patients (age range, 28-70 years) with dissecting aneurysms of the PICA were treated at our center by endovascular occlusion with Guglielmi detachable coils or glue and followed for up to 30 months. Inclusion of patients in the study was based on careful angiographic assessment of the vascular anatomy and collateral supply of the posterior fossa. When on the basis of the anatomy, potential lack of sufficient collaterals was suggested, a test occlusion was performed to determine the feasibility of an endovascular approach. Four additional cases, which have been described in the literature, were included in the analysis of results. RESULTS: In all patients, the aneurysm was successfully occluded with no apparent procedure-related complications. Follow-up studies showed stable and complete occlusion of the aneurysm in all patients with no long-term neurologic deficits. CONCLUSIONS: Endovascular treatment by aneurysm and parent artery occlusion is a relatively safe and reliable alternative to surgery for isolated dissecting aneurysms of the PICA.     

Isolation of the fourth ventricle causing transtentorial herniation: neurosonographic findings in premature infants.

OBJECTIVE. Significant posthemorrhagic enlargement of the fourth ventricle occurs only in a small minority of patients. Although entrapment or isolation of any ventricle can occur, the fourth ventricle is the most common site. This study was undertaken to better understand enlargement of the fourth ventricle after intraventricular hemorrhage and the neurosonographic features of isolation and transtentorial herniation. MATERIALS AND METHODS. The sonographic records of 1535 premature neonates were reviewed for evidence of intracranial hemorrhage and ventriculomegaly. Cranial sonography was performed within the first 3 days of life in all neonates born in our hospital and within the first week of admission for transferred neonates. Follow-up sonograms were obtained at weekly intervals until discharge from the nursery. Intracranial hemorrhages were classified as severe when the hemorrhage was associated with hydrocephalus, intraparenchymal hemorrhage, or both. RESULTS. Intracranial hemorrhage occurred in 761 (50%) of 1535 patients, with severe hemorrhages in 229. Ten had massive enlargement of the fourth ventricle with isolation in six of the 10 after shunt placement. Isolation of the fourth ventricle causing transtentorial herniation occurred in three. Of the patients with isolation of the fourth ventricle, two had associated infection and ventriculitis caused by Klebsiella oxytoca and one had Candida ventriculoencephalitis. CONCLUSION. The early recognition of the neurosonographic features of an enlarged fourth ventricle causing transtentorial herniation has important therapeutic implications. Although isolation can occur after intraventricular hemorrhage alone, infection and ventriculitis are significant factors in the development of an isolated fourth ventricle.     

Possible electrical stimulation on rostral ventrolateral medulla that causes significant hypertensive and tachycardic changes during endovascular treatment of a PICA aneurysm abutting the left medullary sulcus

We report the case of a 43-year-old man who underwent endovascular treatment for posterior inferior cerebellar aneurysm. Significant hemodynamic changes were observed as electric stimulation was applied during coil detachment for a PICA aneurysm. We postulate that changes in heart rate and blood pressure during coil detachment were due to the electric stimulation of the tonic vasomotor center located in the rostral ventrolateral medulla, which was very close to the PICA aneurysm.     

Stent-assisted coil embolization of wide-necked posterior inferior cerebellar artery aneurysms

Introduction

Endovascular coil embolization of posterior circulation aneurysms has advantages over a surgical approach. However, the application of coil embolization is sometimes limited in wide-necked posterior inferior cerebellar artery (PICA) aneurysms, which are incorporating the origin of the branch. Presented here is a series of patients who were subjected to stent-supported coil embolization of PICA aneurysms.

Methods

From a prospective data repository, we retrieved records of seven consecutive patients with PICA aneurysms, all of whom were treated by stent-assisted coil embolization between January 2010 and November 2012. Outcomes were analyzed in terms of aneurysm morphology and clinical status.

Results

In all seven instances, the stents were placed from proximal PICA to vertebral artery (VA). A retrograde approach, via contralateral VA, was performed in five patients, where the origin of PICA from VA assumed an acute angle. In the other two patients, where the angles were obtuse, the stenting was done antegrade, via ipsilateral VA. Out of five patients with retrograde approach, single puncture and a single guiding catheter sufficed in three patients, whereas the remaining two patients required dual puncture and two guiding catheters. Endovascular treatments, as performed, resulted in excellent outcomes for all seven patients, although an asymptomatic thrombus developed in one patient with a ruptured aneurysm.

Conclusion

For coil embolization of PICA aneurysm requiring stent protection, either ipsilateral or contralateral VA access routes may be used, depending on the angle of PICA origin and the configuration of the aneurysm.     

The bihemispheric posterior inferior cerebellar artery

Rarely, a solitary posterior inferior cerebellar artery (PICA) will supply both cerebellar hemispheres. We report four cases of this variant. We present a retrospective review of clinical information and imaging of patients undergoing angiography at our institution to identify patients with a bihemispheric PICA. There were four patients: three males and one female. One patient presented with a ruptured arteriovenous malformation, and one with a ruptured aneurysm. Two patients had normal angiograms. The bihemispheric PICA was an incidental finding in all cases. The bihemispheric vessel arose from the dominant left vertebral artery, and the contralateral posterior inferior cerebellar artery was absent or hypoplastic. In all cases, contralateral cerebellar supply arose from a continuation of the ipsilateral PICA distal to the choroidal point and which crossed the midline dorsal to the vermis. We conclude that the PICA may supply both cerebellar hemispheres. This rare anatomic variant should be considered when evaluating patients with posterior fossa neurovascular disease.     

Retrograde Stent Placement for Coil Embolization of a Wide-Necked Posterior Inferior Cerebellar Artery Aneurysm

Wide-necked aneurysms of the posterior inferior cerebellar artery (PICA) are infrequently encountered in cerebrovascular practice, and endovascular treatment is difficult or impossible even with the use of several neck remodeling techniques. We present the case of a patient with a wide-necked aneurysm of the PICA, which was treated by the retrograde stenting through the contralateral vertebral artery and vertebrobasilar junction with antegrade coil embolization.     

Ruptured, dissecting posterior inferior cerebellar artery aneurysms: endovascular treatment without parent vessel occlusion

Introduction Treatment of a dissecting aneurysm of the medullary segments of the posterior inferior cerebellar artery (PICA) usually entails trapping of the diseased arterial segment with possible sacrifice of brainstem perforators. The goal of the work was to review our experience with selective coiling of ruptured, dissecting aneurysms of the anterolateral segments of the PICA without parent vessel occlusion. Methods Eleven consecutive patients (9 women, 2 men, mean age 47.2 years) were retrospectively reviewed from a prospectively acquired neuroradiological database. On admission three patients had Hunt and Hess (HH) grade I, three HH grade II, two HH grade III, and one HH grade IV. Outcome was evaluated according to the modified Rankin scale (mRS) score. Follow-up (mean:19.4 months) consisted of magnetic resonance angiography and/or digital subtraction angiography in ten patients. Results Ten patients had mRS score 0 and one mRS score 2. No treatment failure occurred. The aneurysm was completely occluded in seven patients, a neck residue was present in two, and a loose coil mesh was present in two. Recurrence occurred in three patients, and all were successfully retreated for a total of 13 procedures. Procedure-related complications were all without clinical consequences and included a coil perforation in one procedure and stagnant filling of the parent vessel in six procedures. PICA occlusion did not occur in any patient. Conclusion Coiling of ruptured, isolated dissecting aneurysms of the PICA without parent vessel occlusion is feasible, relatively safe and effective in preventing early/medium-term rebleeding. A strict angiographic follow-up program is, however, necessary to detect recurrence.     

Bleeding patterns in ruptured posterior fossa aneurysms: a CT study

Computed tomography of the brains in 20 patients with acute rupture of posterior fossa aneurysms was reviewed and analyzed retrospectively. Findings were compared with those from 44 cases described in the literature and with the findings in ruptured supratentorial aneurysms. Extravasated blood was observed in 19 of 20 patients (95%); intraventricular hemorrhage (IVH) in 17 of 20 (85%); and subarachnoid hemorrhage (SAH) in 13 of 20 (65%). These values were significantly higher than those previously reported and suggest that, during the acute phase of rupture, extravasated blood may be detected with the same frequency in either infratentorial or supratentorial ruptured aneurysms. Subarachnoid hemorrhage was accompanied by IVH, prominent in the fourth ventricle and without intraparenchymal hematoma, in 11 patients (55%). This pattern is highly suggestive of ruptured posterior fossa aneurysms. Intraventricular hemorrhage without SAH was noted in five patients (25%) and specifically represented ruptured posterior inferior cerebellar artery aneurysms. Subarachnoid hemorrhage without IVH was noted in only two patients (10%).     

Arterial and venous signs of tumors within the fourth ventricle

Summary A positive diagnosis of tumors located within the fourth ventricle should be based on specific signs therby excluding other space occupying lesions in the posterior fossa. These are a typical omega form of the hemispheric cerebellar branches on the lateral projection, and an also typical inverted 3 form of the PICA in the semiaxial projection. Alteration of the veins of the lateral recess of the fourth ventricle and of the precentral cerebellar vein are important venous signs. Indirect signs are found in the absence of tonsillar herniation with arterial and venous signs of AP stretching of the cerebellar tonsils.     

Improved detection of intraventricular cysticercal cysts with the use of three-dimensional constructive interference in steady state MR sequences

BACKGROUND AND PURPOSE: Before the advent of MR imaging, intraventricular cysts were difficult to diagnose noninvasively. Among the invasive procedures used were contrast ventriculography and CT ventriculography. MR imaging, with its multiplanar imaging capabilities, excellent depiction of tissue contrast, and versatile parameters, is an important tool in the assessment of intraventricular cystic lesions. We investigated the role of three-dimensional constructive interference in steady state (3D-CISS) MR sequences in the evaluation of intraventricular cysticercal cysts. METHODS: The study group comprised 11 patients with intraventricular cysticercal cysts. MR studies included spin-echo (SE) T1-weighted, turbo-SE T2-weighted, and 3D-CISS sequences. All images were obtained on a superconducting 1.5-T MR unit. The routine and 3D-CISS sequences were reviewed and interpreted separately by two neuroradiologists. RESULTS: All patients underwent surgery for excision of intraventricular cysticercal cysts. Eight patients had cysts in the fourth ventricle, two in the lateral ventricle, and one in the third ventricle. SE T1-weighted images showed the cystic wall in nine cases, the scolex in four, and the cystic fluid in two. Turbo-SE T2-weighted images showed the cystic wall and scolex in three and four cases, respectively. The routine sequences did not show the scolex, cystic wall, or cystic fluid together in any of the 11 patients. 3D-CISS images showed the scolex in all 11 patients and the cystic wall and cystic fluid in eight patients each. In seven of the 11 patients, 3D-CISS images showed the scolex, cystic wall, and fluid together. CONCLUSION: The 3D-CISS sequence is more sensitive and specific than routine SE sequences in the diagnosis of intraventricular cysticercal cysts.     

Sudden fatal or non-operable bleeding from ruptured intracranial aneurysm Evaluation by post-mortem angiography with vulcanising contrast medium

Summary A series of medicolegal autopsies on 76 patients with fatal outcome following haemorrhage from ruptured intracranial aneurysm comprised 63 surgical patients and 13 non-surgical patients (M : F 6:7; mean age 44.0 ± 18.1 years), all of the latter with sudden fatal course or dramatically poor clinical condition on admission. The medicolegal autopsy was performed because of the sudden and unexpected nature of the death, or to exclude surgical malpractice. Postmortem angiography with vulcanising contrast medium disclosed intraventricular haemorrhage (IVH) in 12 (92%) of the non-surgical fatalities, whereas IVH was thus characterized in only 17 (27%) of the 63 fatalities who had undergone neurosurgery (P < 0.0001). The most common type of haemorrhage among surgical cases was, instead, subarachnoid haemorrhage (SAH) (P<0.05). In 35 of the 76 cases (46%), casts of cerebral arteries demonstrated vasospasm-induced segmental narrowings, but such narrowings were no more frequent among the non-surgical cases than in surgical cases, nor did these narrowings correlate with IVH. In non-surgical patients, the haemorrhage most commonly originated from a ruptured aneurysm of the middle cerebral artery (P < 0.05), an event more frequently associated with the presence of IVH (P < 0.05) than without it. The results indicate that the main cause for sudden and unexpected death or rapidly developed poor non-operable clinical condition of patients with ruptured intracranial aneurysm is an IVH from a middle cerebral artery aneurysm, complicated in many cases by cerebral artery vasospasm.     

CT导向侧脑室引流伴尿激酶注入治疗脑室出血

目的 :评估CT导向细针引流及尿激酶治疗对脑室出血患者的治疗价值。材料和方法 :脑室出血患者随机分成两组脑室引流组及对照组 ,均为 60例 ,比较两组疗效。结果 :侧脑室引流组基本痊愈 17例 ,显著进步 2 9例 ,进步 5例 ,死亡 9例 ,病死率为 15 .0 % ,存活的 5 1例患者住院 3 5d期间肢体肌力均提高了Ⅱ级。对照组 (保守治疗组 ) ,基本痊愈 0例 ,显著进步 1例 ,进步 3例 ,无变化 8例 ,死亡 48例 ,病死率为 80 .0 % ,存活的 12例中仅 3例在病后 3 5d内瘫痪肢体肌力改善Ⅱ级 ,两组比较差异有显著性 (P <0 .0 5 )。结论 :CT导向侧脑室引流及尿激酶注入和 (或 )腰穿置管间断放液等方法治疗脑室出血 ,安全简便、且穿刺准确率较高、疗效明显优于保守治疗组。     

Posterior inferior cerebellar artery aneurysms: incidence, clinical presentation, and outcome of endovascular treatment

BACKGROUND AND PURPOSE: Results of endovascular treatment of PICA aneurysms are not well established. The purpose of this study was to report incidence, clinical presentation, and outcome of endovascular treatment in 46 patients with 47 posterior inferior cerebellar artery (PICA) aneurysms.MATERIALS AND METHODS: Of 2169 aneurysms treated between January 1995 and March 2007, 60 were located on the PICA (incidence, 2.8%). Forty-seven proximal PICA aneurysms in 46 patients were treated with endovascular techniques, 37 ruptured (79%) and 10 unruptured (21%). Four patients presented with lower cranial nerve palsies. Mean aneurysm size was 6.8 mm (median, 6 mm; range, 2–32 mm). Forty-three aneurysms were occluded with coils (6 including the PICA origin), and 4 were treated with proximal vertebral artery (VA) occlusion.RESULTS: Four aneurysms treated with proximal VA occlusion were not occluded. Procedural rupture occurred in 9 aneurysms leading to death in 2 patients and to permanent disability in 1 patient. One patient developed lateral medullary and cerebellar infarctions after PICA occlusion. Combined mortality and morbidity was 8.6% (4 of 46). Outcome at 6 months in 38 surviving patients was good in 35 and moderate in 3. No hemorrhage occurred during 109 patient-years of follow-up. Symptoms of mass effect resolved in all 4 patients.CONCLUSION: In our experience, PICA aneurysms were challenging lesions, prone to procedural rupture. In some instances, endovascular treatment required occlusion of the parent PICA; usually this was well tolerated. In other instances, treatment required occlusion of the VA. Although this was effective in alleviation of symptoms of mass effect, it was not effective in causing thrombosis of the aneurysm.

Aneurysms of the posterior inferior cerebellar artery (PICA) are rare. Surgery for these aneurysms is challenging due to the deep location and intimate relation with the medulla and cranial nerves IX, X, and XI.^1–8 Although endovascular treatment of intracranial aneurysms is increasingly used as an alternative to surgery, endovascular results of PICA aneurysms are not well established.^9–12 In this study, we report our experience with endovascular treatment of 47 proximal PICA aneurysms in 46 patients.     

An isolated fourth ventricle in neurosarcoidosis: MRI findings

We report on an isolated enlargement of the fourth ventricle in a patient with neurosarcoidosis which developed 3 years after the insertion of a ventriculo-atrial shunt. Repeated MRI images were obtained in a patient with known neurosarcoidosis between 1995 and 2000. Imaging findings were correlated to the medical course of the patient, who developed a hydrocephalus and a trapped fourth ventricle consecutively. The isolation was presumably due to granulomatous inflammation of the ependyma surrounding the fourth ventricular outlets. The isolated fourth ventricle was responsible for a deterioration of neurological status. Neurosarcoidosis is a severe complication in sarcoidosis patients. An isolated enlargement of the fourth ventricle is a rare complication in clinically deteriorated patients with neurosarcoidosis and ventricular drainage, which may require neurosurgical treatment.     

Chordoid Glioma with Intraventricular Dissemination: A Case Report with Perfusion MR Imaging Features

Chordoid glioma is a rare low grade tumor typically located in the third ventricle. Although a chordoid glioma can arise from ventricle with tumor cells having features of ependymal differentiation, intraventricular dissemination has not been reported. Here we report a case of a patient with third ventricular chordoid glioma and intraventricular dissemination in the lateral and fourth ventricles. We described the perfusion MR imaging features of our case different from a previous report.     

Three-dimensional MRI of hemifacial spasm with surgical correlation

MRI was used to investigate 100 patients with hemifacial spasm, using 3D-FT T2-weighted (CISS) and contrast-enhanced 3D-FT T1-weighted (turbo-FLASH) sequences in all cases. MR angiography was performed in 54 patients, using 3D-MT FISP images. Decompression of the facial nerve through a retromastoid craniotomy was performed in all patients. Hemifacial spasm caused by tumours in the cerebellopontine angle was not included. Vascular contact with the facial nerve root-exit zone or at the internal auditory canal was present in 96 of 100 patients with hemifacial spasm. The vessel responsible was the vertebral artery (VA) in 18 cases, the posterior inferior cerebellar artery (PICA) in 23, the anterior inferior cerebellar artery (AICA) in 22, the VA and PICA in 24, VA and AICA in 3, PICA and AICA in 1, VA, PICA and AICA in 4, and a vein in 1 case. CISS images showed compressive vascular loops better than contrast-enhanced turbo-FLASH images alone. The sensitivity of MRI was high, since only one false-negative case was found among the 100 patients who underwent surgery. Received: 10 July 1995 Accepted: 4 June 1996     

小脑后下动脉瘤血管内栓塞治疗的初步临床研究

目的 探讨小脑后下动脉(PICA)瘤栓塞治疗的方法及效果.方法 回顾性分析21例PICA瘤经血管内栓塞治疗的临床资料,根据DSA资料估计动脉瘤的解削分段.采取单纯弹簧圈栓塞8例、单纯液体胶栓塞5例、弹簧圈联合液体胶栓塞2例、支架辅助弹簧圈栓塞2例、球囊辅助弹簧圈PICA闭塞4例,用格拉斯哥预后(GOS)评分评估疗效.结果 单纯弹簧圈致密栓塞5例,90%以上栓塞2例,85%栓寒1例;单纯液体胶栓塞的5例及弹簧圈联合液体胶栓塞的2例均达到致密栓塞;支架辅助弹簧圈栓塞的2例90%以上栓塞;球囊辅助弹簧圈完全闭塞载瘤动脉3例,90%以上栓塞1例.术后脑干穿支动脉闭塞导致死亡1例,术后1周新发神经功能障碍1例,其余未见再出血及小脑损害症状.术后随访6～60个月,平均(22±8)个月.COS评分Ⅰ级1例,Ⅱ级1例,Ⅲ级2例,Ⅳ级5例,Ⅴ级12例.结论 根据PICA瘤的解剖分段选择不同的栓塞方法,可取得良好的治疗效果.