Clinical evaluation of an isolated fourth ventricle

Since the introduction of the CT scan in 1976, we have experienced 6 cases of the isolated fourth ventricle among 244 hydrocephalic patients (2.5%). Age at diagnosis of the isolated fourth ventricle ranged from 1 year 8 months to 13 years (mean age, 8 years, 6 months). The time interval between the first shunting procedure and the diagnosis of the isolated fourth ventricle varied from 1 year 5 months to 7 years 4 months (mean interval, 4 years 1 months). The prior hydrocephalus were due to intraventricular hemorrhage in two patients, meningomyelocele in a patient and brain tumor in three patients. Two patients had history of cerebrospinal fluid (CSF) infection and five cases underwent multiple shunt revisions. Posterior fossa signs were evident in all cases. It was quite easy to make a diagnosis of the isolated fourth ventricle with CT scan, which demonstrated a large rounded or pear-shaped midline cyst in the posterior fossa. Slit-like lateral ventricles were noted in three cases, while the remaining three had enlarged lateral ventricles. Ventriculography confirmed the isolation of the fourth ventricle in 5 cases. Metrizamide which had been injected into the fourth ventricle was diluted when CT scan was performed 48 hours later, and contrast medium disappeared since then. Magnetic resonance imaging (MRI) well showed the characteristic findings of the isolated fourth ventricle: cystic dilatation of the fourth ventricle, compression and distortion of the brain stem, upward tentorial herniation, occlusion of the aqueduct, downward displacement of the occipital lobe, septum formation of the fourth ventricle and accompanied anomalies such as, Chiari malformation or syringomyelia.(ABSTRACT TRUNCATED AT 250 WORDS)     

CT stereotaxy guided lateral trans-cerebellar programmable fourth ventriculo-peritoneal shunting for symptomatic trapped fourth ventricle

A trapped fourth ventricle is a rare clinico-radiological entity producing symptoms suggestive of a progressive posterior fossa mass lesion. It is mainly reported in children as a late complication of lateral ventricular shunting to relieve infantile post-meningitic or post-hemorrhagic hydrocephalus. Optional treatment of the trapped fourth ventricle remains controversial. Placement of fourth ventricular shunting via a conventional midline approach can be fraught with complications in about 40% of the patients. Authors report a successful CT Stereotaxy guided high pressure (80 mm H(2)O) programmable fourth ventriculo-peritoneal shunting via a lateral trans-cerebellar approach in a 14-year-old girl with a trapped fourth ventricle, which occurred as a late complication of ventriculo-peritoneal shunting in her infancy. Her preoperative symptoms of raised intracranial pressure, bobble-head doll syndrome and bilateral abducens palsies completely improved following the surgery. Lateral trans-cerebellar stereotactic placement of the fourth ventricular catheter and the use of high-pressure (low flow) programmable shunt (to avoid complications associated with over drainage) are beneficial in some patients with trapped fourth ventricle.     

Reexpandability of the ventricular system of hydrocephalic children in the event of shunt occlusion

Introduction To estimate intracranial volume-buffering capacity in the event of shunt occlusion, the reexpandabilty of the lateral ventricles and clinical manifestations were examined in shunt-dependent hydrocephalic children.Material and methods This retrospective study was performed in 38 children who displayed acute deterioration due to spontaneous shunt obstruction. At the time of shunt obstruction, patients with small lateral ventricles [small ventricle (SV) group: Evans' index ≤35, n=13] showed significantly more rapid deterioration into lethargy after onset than those with large lateral ventricles [lateral ventricle (LV) group: Evans' index >0.35, n=25]. All patients in the SV group were 3 years or older at the time of shunt obstruction or had a long period (5.2 years) between initial shunting and shunt occlusion. Their Evans' index was less than 0.33 prior to shunt obstruction.Conclusions While a shunt is functioning, the factors predictive of reduced ventricular reexpandability include (1) a lateral ventricular size smaller than 0.33 on the Evans' index and (2) either an age of more than 3 years in children who have undergone initial shunting at less than 1 year of age or over 5 years of the period after initial shunting.     

Complications after shunting isolated IV ventricles

An isolated IV ventricle in chronically shunted patients is being reported with increasing frequency. Complications associated with posterior fossa shunting, however, have seldom been described. Between January 1986 and December 1995, we treated 292 children younger than 16 years for hydrocephalus: 7 (2.4%) developed an isolated IV ventricle, and 5 of these were symptomatic with posterior fossa signs. These 5 patients required posterior fossa shunting, after which their neurological status improved. However, 1 week and 6 weeks after surgery, respectively, 2 patients developed new cranial nerve deficits related to a slit-like IV ventricle with secondary irritation of the brain stem by the IV ventricular catheter. Shortening the catheter and replacing the valve eliminated the cranial nerve palsies, implying that these complications were not caused by direct injury of the brain stem during placement of the shunt. Alternative surgical techniques and the use of different (flow-regulating) valves may avoid such complications. Received: 3 June 1996     

Outlet fenestration for isolated fourth ventricle with and without an internal shunt

Conventional shunting of isolated fourth ventricle is notorious for leading to frequent and severe complications. We present four patients with isolated fourth ventricle who have been treated with open posterior fossa surgery together with either outlet fenestration alone or outlet fenestration and a fourth ventricle-spinal subarachnoid space (SSS) shunt. A survey of the relevant literature did not yield any other case reports of fourth ventricle shunting to the SSS under such circumstances. This paper discusses the reasons for choosing this mode of treatment. The main advantage of this technique is that the catheter is inserted along the anatomical long axis of the fourth ventricle. This positioning lessens the possibility of irritating or penetrating the brain stem. Moreover, as a more physiological solution, the shunt does not require a valve system. Because of these advantages, internal fourth ventricle-SSS shunting is proposed as a valid alternative to the "classic" fourth ventriculo-peritoneal shunt.     

第四脑室肿瘤的显微外科治疗

目的总结第四脑室肿瘤的显微外科治疗效果及手术策略。方法第四脑室肿瘤患者36例,均在显微镜下或神经内镜辅助下切除肿瘤。肿瘤全切除24例,次全切除12例。结果术后恢复良好13例,死亡3例,缄默症4例,脑积水16例,其中12例行侧脑室．腹腔分流术,4例行脑室心房分流术。术后随访：29例生活、学习良好,3例死亡,1例失访。结论正确及时的诊断、熟悉四脑室的显微解剖、选择合适的手术入路、熟练的显微手术技巧、适当应用神经内镜、积极处理术后脑积水是提高第四脑室肿瘤疗效的关键。     

显微手术治疗第四脑室肿瘤17例临床体会

目的分析显微手术治疗第四脑室肿瘤的临床方法与效果。方法将2010-07-2015-07河南中医药大学第一附属医院确诊的第四脑室肿瘤患者,均择期行显微手术治疗,对效果、术后并发症进行观察对比。结果本组14例患者行肿瘤全切术,3例患者行次全切术。术后出现并发症2例11.7%。其中幕上远隔硬膜外血肿1例,皮下积液1例。对症处理后均短期内转归,未对患者预后治疗产生不良影响。结论显微手术治疗第四脑室肿瘤的临床效果确切,术者需了解第四脑室及脑干的重要神经结构,注重对脑干功能的保护,脑水肿患者预先行侧脑室外引流,以巩固显微术下肿瘤病灶的切除效果。     

Endoscopic transaqueductal or interventricular stent placement for the treatment of isolated fourth ventricle and pre-isolated fourth ventricle

Object

The aim of our study is to evaluate the effectiveness of endoscopic transaqueductal or interventricular stent placement into the fourth ventricle for isolated fourth ventricle (IFV) and pre-isolated fourth ventricle (PIFV), in which occlusion of the fourth ventricle outlets and dilation of the fourth ventricle are seen while the aqueduct is still patent.

Methods

We retrospectively analyzed pediatric patients who underwent endoscopic stent placement for IFV or PIFV.

Results

Five patients with IFV and four patients with PIFV underwent endoscopic stent placement. The mean age was 11.5 months. Three patients with IFV underwent aqueductoplasty with stent connected to an extracranial shunt system. Two patients with IFV and supratentorially protruded fourth ventricle underwent interventriculostomy with stent. In these patients, the stent was not connected to the shunt system as functional shunt had been already placed using the contralateral ventricle. In four patients with PIFV, transaqueductal stent was placed and connected to the extracranial shunt system. In all patients, preoperative symptoms improved and magnetic resonance imaging demonstrated reduction of the size of the fourth ventricle. The mean follow-up period was 49.6 months (range 5 to 99 months). Three patients (33 %) underwent reoperation due to obstruction of the abdominal catheter, partial occlusion of the ventricular catheter, and retraction of the fourth ventricular catheter.

Conclusion

The endoscopic transaqueductal or interventricular stent placement into the fourth ventricle for the treatment of IFV is considered to be effective and safe. The transaqueductal stent placement for PIFV is also considered to be effective for resolution of symptoms and prevent progression into IFV.     

软性内镜下个性化手术治疗第四脑室流出道梗阻

目的 总结软性神经内镜下个性化手术治疗第四脑室流出道梗阻的指证、方法及效果.方法 对应用软性神经内镜个性化手术治疗第四脑室流出道梗阻32例患者的临床资料进行回顾性分析.结果 单纯第四脑室正中孔造瘘9例,第四脑室正中孔造瘘加第三脑室底造瘘5例,导水管成形加第三脑室底造瘘5例,导水管成形加第四脑室正中孔造瘘2例,单纯第三脑室底造瘘11例.术后脑脊液电影检查显示导水管区脑脊液流动良好26例,枕大孔区第四脑室正中孔脑脊液流动良好10例,第三脑室底瘘口脑脊液流动良好15例,脑脊液电影检查结果不满意但临床症状缓解者2例,术后仍有高颅压表现者5例,其中2例经脑脊液外引流数日后缓解,3例复行脑室-腹腔分流术.所有患者无明显手术并发症出现.结论 软性内镜下可以经额部锁孔导水管入路对第四脑室流出道梗阻进行个性化手术治疗,使部分患者恢复正常脑脊液循环,摆脱分流依赖,但应严格选择手术指证.

Abstract：

Objective To summarize the indication, method and effect of individual flexible endoscopic procedure for treatment of obstruction of fourth ventricle outlet. Methods The clinical data of 32 cases of obstruction of fourth ventricle outlet treated by individual flexible endoscopic procedure from July,2006 to June,2010 were analyzed retrospectively. Results Single endoscopic fourth ventriculostomy (EFV)was performed in 9 cases, EFV with endoscopic third ventriculostomy (ETV) in 5 cases, endoscopic aquductoplasty (EAP) with ETV in 5 cases, EAP with EFV in 2 cases, and single ETV in 11 cases. In cine phase -contrast magnetic resonance imaging(cine - MRI), 26 (81.3%) cases showed fine circulation of CSF in aqueduct, 10 (31.3%) fine circulation of CSF in Magendie's foramen and 15 (46.9%) fine circulation of CSF in the orificium fistulae of third ventricle floor. 2 (6. 3% ) cases were symptomatic relief although unsatisfactory result appeared in postoperative cine- MRI. Of 5 ( 15.6% ) cases who still suffered from postoperative intracranial hypertension, 2(6.3%) cases were released by external ventricle drainage for several days, 3 (9. 4% ) cases had to had ventriculoperitoneal (VP) shunt because the intracranial hypertension could not be released. There was no complication related to operation appeared in all patients. Conclusions The obstruction of fourth ventricle outlet could be treated individually through trans - aqueduct approach via frontal key - hole with flexible neuroendoscope. Regular CSF circulation could be put back with shunt -free in partial patients, but the operative indication should be obeyed strictly.     

经小脑延髓裂入路行第四脑室手术的显微解剖研究

目的 探讨经小脑延髓裂入路到达第四脑室的解剖研究，及在不切开下蚓部的情况下如何分离此裂隙以获得最佳的手术视野。方法 应用显微外科解剖技术，对经甲醛固定、颈内动脉系统彩色乳胶灌注的10具成人尸头标本，在手术显做镜下解剖分离小脑延髓裂，观察第四脑室顶部、底部及外侧隐窝等，切开脉络膜等暴露第四脑室各区域。结果 小脑延髓裂充分暴露后，可以不切开下蚓部，即可获得第四脑室各壁的良好术野。开放小脑延髓裂可依据第四脑室壁的位置及需要暴露的程度分为3种方式：广泛型(导水管型)、外侧壁型及外侧隐窝型。结论 经小脑延髓裂入路可通过正常的解剖间隙到达第四脑室以及脑干，且术野充分，可减少手术的损伤及术后并发症。因广泛型可以最大程度显露第四脑室底部及各区域，因此可以作为该入路的标准方式。     

侧脑室副三角区穿刺治疗脑积水

目的探讨脑室穿刺部位对脑室-腹腔分流术术后效果的影响。 方法选取阜矿集团总医院自2008年1月至2015年12月收治脑积水患者49例作为实验组,均采用侧脑室副三角区定位穿刺行脑室-腹腔分流术。另取阜矿集团总医院2001年10月至2007年12月术前未定位以侧脑室三角区为穿刺点行脑室-腹腔分流术,共35例作为对照组,比较两组的术后并发症情况。 结果对照组有3例堵管,7例感染,均拔管抗感染二次手术,实验组有1例感染,无堵管、硬膜下血肿、积液、低颅压、裂隙综合征等并发症。两组并发症发生率差别显著(χ²=12.63,P=0.000)。 结论副三角区穿刺,可防止三角区脉络丛包裹分流管头端,降低分流术的并发症。     

儿童蛛网膜囊肿-腹腔分流术后继发裂隙脑室综合征的治疗

目的 探讨颞叶蛛网膜囊肿行囊肿-腹腔分流术后出现的裂隙脑室综合征的早期诊断依据,合理有效的治疗方法以及预防这种并发症的措施.方法 回顾性分析研究了经过本文通信作者治疗的6例颞叶蛛网膜囊肿行囊肿-腹腔分流术后出现裂隙脑室综合征患儿的影像学资料、治疗经过和治疗结果.结果 男4例,女2例.平均发病年龄57.5个月.治疗方法为使用可调压力的抗虹吸分流管泵更换原有分流管泵或联合使用脑室-腹腔分流.6例患者临床症状完全消失,平均随访30个月,未见症状复发.结论 使用可调压力的抗虹吸分流管泵更换原有分流管泵或联合脑室-腹腔分流术对于裂隙脑室综合征是一种有效的治疗措施.避免使用低压的无抗虹吸作用的分流管能够有效地预防蛛网膜囊肿-腹腔分流术后出现裂隙脑室综合征.

Abstract：

Objective To investigate early diagnosis evidences, optimal therapeutic strategies and the prophylactic methods of the slit - ventricle syndrome(SVS) in the temporal lobe arachnoid cysts patients who received the cyst - peritoneal(CP) shunting.Method Six cases of SVS in the temporal lobe arachnoid cysts patients who received the CP shunting were treated by the senior author from Jan 2005 to Jan 2009.The radiological data, treatment process and therapeutic results were reviewed retrospectively.Results There were 4 male and 2 female patients.The mean age of presentation was 57.5 months.The final treatment was to change the original shunt with the programmable valve or combined with the ventricular - peritoneal(VP)shunting.All the symptoms of the patients disappeared totally, and the mean follow - up duration was 30mouths.Conclusions To use programmable shunts to substitute for the original shunt or combined with inserting a VP shunt is an optimal therapeutic method for SVS.The use of low - pressure shunts to treat the ararchoid systs should be abandoned unless dictated by specific indications.     

Fourth ventricle computed tomography indexes: standardisation and characteristics in neurocysticercosis

OBJECTIVES: to propose standardisation of fourth ventricle dimensions and to study its characteristics in neurocysticercosis. METHOD: a control group (CG) constituted by 114 individuals with normal CT, and 80 patients with neurocysticercosis composed the group with neurocysticercosis (GN). Measures of the inner cranial diameter (Cr), fronto-polar distance between both lateral ventricles (FP), antero-posterior (AP) and latero-lateral (LL) fourth ventricle width based the standardisation of six indexes. RESULTS: AP/Cr, AP/LL and AP/FP were the more discriminative indexes, presenting in CG the mean values of 0.063, 0.267 and 0.582, respectively. The indexes in GN had values statistically higher than in CG. From GN, 51 patients had increased indexes values above 2 standard deviation of the CG mean. AP/Ll was >/= 1 in 95% of patients with ventricular shunting and in 88% with depression. It also occurred in 73% patients with satisfactory follow-up and in everybody who died. CONCLUSION: AP/Cr, AP/LL and AP/FP may represent fourth ventricle dimensions.     

Disproportionately large communicating fourth ventricle resulting from adjustable valve shunt in an infant

Disproportionately large communicating fourth ventricle (DLCFV) is usually experienced in adults with no previous experience of shunting. We present a case of an infant with an enlarged fourth ventricle similar to isolated fourth ventricle (IFV) which appeared after shunting. The patient's brain stem symptoms and the abnormal appearance of the fourth ventricle were dramatically ameliorated simply by reducing the opening pressure of the adjustable valve of the ventriculo-peritoneal shunt. The present case suggests that in the present era, with adjustable or programmable valve shunt a common procedure, DLCFV may occur, at least temporarily, even in infants and even after shunting.     

Infantile hydrocephalus and the slit ventricle syndrome in early infancy

Slit ventricle syndrome is well known as a complication in the treatment of hydrocephalus by shunting. It is generally considered to be a chronic (but not acute) complication, occurring years after the shunt procedure; there has been no report of this syndrome occurring before 1 year of age. The authors present infantile cases that developed a severe form of this syndrome shortly after shunt procedures and discuss the pathophysiology in comparison to experience with older cases. The causative factor was thought to be extremely low intracranial pressure with resultant microcephalus created by double or multiple shunt placement. The condition resulted in rapid onset of coma and respiratory arrest, which was successfully treated by subtemporal decompression or placement of an antisiphon device, with insertion of a higher pressure valve. The specific characteristics of infantile hydrocephalus are analyzed in the light of this complication from a series of 58 treated infants. In a follow-up of over 1 year in 42 cases, analysis revealed that slit ventricle occurs most frequently in immature young infants shunted before 1 month of age (85.7% or 18/21 cases). In contrast, subdural hematoma after shunting is an extremely rare phenomenon in premature or mature neonates. Slit ventricles were thought to result from high intracranial compliance due to the softer brain and more markedly widened cranial sutures of infantile hydrocephalus in the younger age group. The functioning period of the initial shunt was also much shorter in younger infants, and this may be because the ventricular shrinkage to a slit can cause shunt malfunction with or without developing the slit ventricle syndrome. The authors emphasize that development of slit ventricle after shunt placement should be prevented before it causes a damaging or, occasionally, a life-threatening condition.     

A rare case of trapped fourth ventricle: an unique symptom appeared after fourth ventriculo-peritoneal shunting]

We experienced a unique case of trapped fourth ventricle after shunting for post-meningitic hydrocephalus. A five-year-old infant was diagnosed as meningitis shortly after his birth, and secondarily suffered from hydrocephalus. He underwent lateral-ventriculo-peritoneal shunting, fourth-ventriculo-cisterna-magna shunting and so on, but bilateral abducens palsy appeared. The following head CT and MRI revealed "trapped fourth ventricle". Though there are several case reports of trapped fourth ventricle with abducens palsy, most of them followed enlargement of the fourth ventricle; nevertheless in our case, abducens palsy appeared when the fourth ventricle reduced in size and the symptom vanished when it enlarged. We thought that a traction force to the abducens nerve had occurred also in the condition of reduced fourth ventricle size, because there would have been a dense adhesion after meningitis in his subarachnoidal space. We tried to improve his symptom in one way or another by keeping the fourth ventricle in appropriate volume. His abducens palsy was controlled by switching the on-off valve between forth ventricle and peritoneum. We expect that a higher-pressure programmable shunt valve or a lower-flow-regulating shunt system be invented in order to cope with the cases like ours.     

Shunt-related headaches: the slit ventricle syndromes

Purpose The purpose of this work is to review the pathophysiology and treatment of severe headache disorders in patients having a shunt for hydrocephalus. Materials and methods The literature on the management of the slit ventricle syndrome is reviewed as well as an assessment of personal experiences over a 30-year period in the management of severe headache disorders in shunted patients. Results If the slit ventricle syndrome is defined as severe, life-modifying headaches in patients with shunts and normal or smaller than normal ventricles with ventricular shunts for the treatment of hydrocephalus, there are five different pathophysiologies that are involved in the process. These pathologies are defined by intracranial pressure measurement as severe intracranial hypotension analogous to spinal headaches, intermittent obstruction of the ventricular catheter, intracranial hypertension with small ventricles and a failed shunt (normal volume hydrocephalus), intracranial hypertension with a working shunt (cephalocranial hypertension), and shunt-related migraine. The treatment of these conditions and identifying patients with each condition are facilitated by attempting to remove the shunt. Conclusions Following the analysis of attempts to remove shunts, there are three possible outcomes. In about a quarter of patients, the shunt can be removed without having to be replaced. This is most common in patients treated in infancy for post-hemorrhagic hydrocephalus or patients shunted early after or before brain tumor surgery. Another half of patients have increased intracranial pressure and enlarged ventricles. In these patients, there is an 80% success rate for endoscopic third ventriculostomy. Finally, the most severe form of the slit ventricle syndrome involves intracranial hypertension without ventriculomegaly, which is managed optimally by shunt strategies that emphasize drainage of the cortical subarachnoid space such as lumbo-peritoneal shunts or shunts that include cisterna magna catheters.     

Slit ventricle syndrome successfully treated by a lumboperitoneal shunt

The authors present the case of a 17-year-old man with slit ventricle syndrome, presenting as progressive neurological deterioration after head trauma. Serial computed tomography scans revealed slight ventricular enlargement, suggesting shunt malfunction. Communication between the lumbar subarachnoid space and the lateral ventricles was confirmed by computed tomography cisternography. He underwent a lumboperitoneal shunt, resulting in complete resolution of the symptoms. A lumboperitoneal shunt is considered to be a promising option for the treatment of slit ventricle syndrome. [Neurol Res 1995; 17; 440-442]     

儿童第四脑室肿瘤显微外科治疗策略

目的探讨儿童第四脑室肿瘤的生物学特点及显微外科治疗策略。方法 1998年至2009年收治的儿童第四脑室肿瘤患者45例,对其病理特点、临床表现、影像学变化、手术操作和预后等方面进行回顾性分析。结果肿瘤全切除36例,次全切除及大部切除9例;术后病理示髓母细胞瘤28例,室管膜瘤14例,星形细胞瘤3例;术后临床症状好转32例,无改善10例,恶化2例,1例患者死于严重脑干水肿;术后复查有4例因脑积水行脑室-腹腔分流术。结论儿童第四脑室肿瘤首发症状多种多样,MRI对于诊断与手术有重要的意义,采取合适的显微神经外科策略是提高手术疗效的关键。     

Slit ventricle syndrome after cyst-peritoneal shunting for temporal arachnoid cyst in children--a clinical entity difficult to detect on neuroimaging study

Slit ventricle syndrome, known to occur from malfunction of the shunt procedure for hydrocephalus, is reported after cyst-peritoneal shunt for temporal arachnoid cyst. Two children aged 12 and 10 years, who underwent cyst-peritoneal shunting for a large temporal arachnoid cyst at the age of 10 and 5 years, respectively, recently experienced several episodes of severe headache. Prior to admission, repeated CT scans did not reveal any morphological change in either of these two patients. Evidence of high intracranial pressure by lumbar tap revealed shunt malfunction. Both patients became free of neurological complaints and deficits after shunt revision. Despite elevated intracranial pressure due to shunt malfunction, neuroimaging studies showed no morphological changes in slit ventricle syndrome. Delay in both the diagnosis and prompt treatment may result in complete loss of visual acuity and even death. It is important to suspect this complication in patients with persistent elevated intracranial pressure symptoms and signs after any shunting procedure, regardless of unchanged neuroimaging studies. Once this is suspected, lumbar tap may be necessary and the choice of treatment is shunt revision.