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Isolated unilateral hydrocephalus (IUH) is a condition caused by unilateral obstruction of the foramen of Monro. 1 Etiopathogenic causes include tumors, congenital lesions, infective ventriculitis, intraventricular haemorrhage, and iatrogenic causes such as the presence of contralateral shunts. 2 , 3 Neuroendoscopic management is considered the "gold-standard" treatment in IUH. 4 Even if endoscopic septostomy and foraminoplasty in IUH are well-known procedures, 5 , 6 IUH after an interhemispheric transcallosal transchoroidal approach for removal of a III ventricle colloid cyst is a complication barely described in literature. Video 1 describes this rare complication and the neuroendoscopic treatment adopted, including the operative room setup, patient's positioning, instrumentation needed, and a series of intraoperative tips for the performance of septostomy and Monroplasty via a single, precoronal burr hole. The scalp entry point and endoscope trajectory, homolateral to the dilated ventricle, were planned on the neuronavigation system. The avascular septal zone away from the septal veins and body of the fornix was reached, and the ostomy was performed. At the end of the procedure, Monroplasty was performed, too. The procedure was effective in solving the hydrocephalus and patient's clinical picture. No surgical complications occurred. Imaging demonstrated an evident and progressive reduction of enlarged lateral ventricle. In authors' opinion, the single burr-hole approach, ipsilateral to the enlarged ventricle, provides an optimal identification the intraventricular anatomy and allows Monroplasty to be performed, if deemed feasible during surgery. The patient consented to the procedure. The participants and any identifiable individuals consented to publication of their images., (Copyright © 2024 Elsevier Inc. All rights reserved.)

We present a case series of 7 patients with intraventricular arachnoid cysts of lateral ventricle managed with endoscopic treatment with proposed classification of the cyst based on anatomic extent.In all patients, the lateral ventricle arachnoid cyst was primarily located in the trigone and body of the lateral ventricle. Proposed classification is based on extension of the arachnoid cyst. Type 1 is an arachnoid cyst located in the lateral ventricle only, type 2 is a lateral ventricle arachnoid cyst extending to the quadrigeminal cistern, and type 3 is the lateral ventricle arachnoid cyst extending to the velum interpositum cistern.Two patients were managed with multiple fenestration and septostomy, and in 1 patient where the cyst was not adherent to the ventricular wall it was excised completely. Two patients who had a lateral ventricle cyst located in the atrium but extending to quadrigeminal cyst were managed with 3 fenestrations. Two patients with a lateral ventricle arachnoid cyst located into the atrium of lateral ventricle and extending to the velum interpositum cistern through the choroid fissure were managed with 3 endoscopic fenestrations. Postoperatively, patients were followed clinically and by radiologic imaging. None of the patients reported recurrence until the latest follow-up.Multiple endoscopic fenestrations for lateral ventricle arachnoid cyst according to its location and anatomic extension help to reduce recurrence and good outcome. Cyst excision is recommended only when the cyst wall is easily separable from the lateral ventricle wall. Intraoperative use of thulium light amplification by stimulated emission of radiation helps in achieving early hemostasis and easy perforation of the thick cyst wall.

Infantile choroid plexus papilloma (CPP) associated with multiple peritumoral cysts is a rare variant of CPP, and clinical course and optimal management are largely unknown. A 9-month-old boy presented with a large solid tumor in the left lateral ventricle associated with multiple peritumoral cysts, arachnoid cysts, and hydrocephalus containing xanthochromic fluid with high protein content. Shrinkage of these cysts and resolution of hydrocephalus were achieved after total resection of the hypervascular solid part of the tumor. Histological examination confirmed the solid part of the tumor as CPP and showed that the wall of the peritumoral cysts consisted of reactive gliosis without neoplastic cells. Follow-up magnetic resonance imaging 12 months after surgery revealed that these cysts remained stable. CPP with nonenhancing peritumoral cysts can be managed by resection of only the solid part of the tumor without permanent cerebrospinal fluid diversion.

An entrapped temporal horn (ETH) is one of the critical complications after tumor removal in the lateral ventricle trigone that sometimes becomes life threatening.We sought to develop a novel intraoperative method of prophylactic intraventricular piping (PIP) just after tumor removal to prevent ETH.Three patients with meningiomas in the lateral ventricle trigone were treated by a novel intraoperative method of PIP just after tumor removal to prevent ETH. Silicone catheters normally used as ventricular drainage catheters were cut to 5- to 6-cm length and inserted into the tumor cavity to ensure communication between the temporal horn and the atrium or the body of the lateral ventricle through the piping straddling the trigone.None of our patients developed ETH during the follow-up period without complications caused by the tube placement.PIP might be beneficial to prevent ETH because constant osmotic pressure and constant cerebrospinal fluid pulse wave transmission are maintained between each compartment of the lateral ventricle.

Background Gangliogliomas (GGs) are extremely rare benign neoplasms frequently located within the temporal lobe that usually present with seizures. GGs growing predominantly within the ventricular system (VGGs) are even more infrequent, so definite conclusions concerning their diagnosis and therapeutic management are lacking. Methods A retrospective review of case reports of VGGs was performed from the introduction of modern imaging techniques, including 4 new illustrative cases treated in our department. Results Thirty-four cases were collected. Ages ranged from 10 to 71 years (mean, 26.62 years), and 55.9% were male. Most patients developed symptoms related to high intracranial pressure. The lateral ventricles were predominantly involved (58.8%). Obstructive hydrocephalus was observed in 54.5% of patients. Cystic degeneration and calcification were frequently observed. Surgical treatment was carried out in all cases. Morbidity and mortality were 17.6% and 2.9%, respectively. Gross total tumor resection was achieved in 64.5% of patients. Four patients experienced tumor dissemination along the neural axis. More than 90% of patients maintained a good functional status at last follow-up. Conclusions Despite their low incidence, a diagnosis of VGGs should be considered in young male adults who progressively develop intracranial hypertension, caused by a ventricular mass showing signs of cystic degeneration and calcification. Maximal and safe surgical resection represents the gold standard for the treatment of symptomatic VGGs, although total removal is frequently precluded by difficulties in defining appropriate tumor boundaries. Adjuvant radiotherapy should be considered if an incomplete resection was carried out, especially in World Health Organization grade III neoplasms.

Background Lateral ventricular meningioma (LVM) is a rare entity, accounting for 0.5%–5% of all intracranial meningiomas. This type of meningioma arises from meningothelial inclusion bodies in the tela choroidea and/or mesenchymal stroma of the choroid plexus. Although not yet fully characterized, a membranous structure is frequently observed around LVMs. This study analyzed quiescent and activated fibroblast phenotypes in LVMs with focus on the relationship between tumor growth and development of the membranous structure. Methods This retrospective study analyzed 9 LVM cases for which gross total removal was achieved. Expression of the ependymal cell marker (Forkhead Box J1 [FoxJ1]) was histopathologically evaluated. The distribution of quiescent and activated fibroblasts was also analyzed using anti-fibroblast-specific protein-1 (FSP1)/S100A4 antibody and anti-α-smooth muscle actin (αSMA) antibody, respectively. The control group was 5 cases with primary convexity meningioma for which Simpson grade I removal was achieved. Results Small LVMs (≤30 mm) were covered by a FoxJ1-positive(+) ependymal cell monolayer; no αSMA(+) cells were detected in the tumor; and a thick membrane capsule was not observed. None of the convexity meningiomas showed FoxJ1(+) cells. Large LVMs (>30 mm) had thick membrane capsules without an ependymal cell monolayer, which resembled dura mater. The FSP1/S100A4(+) and αSM(+) cells were clearly concentrated in the peripheral area just below the thick dura mater-like membrane capsules. Conclusions This study found an association between activated fibroblasts and dura mater–like membrane capsules in LVMs. The characteristics of membranous structure in LVMs may differ depending on tumor size.

Objective Localization of the temporal horn of the lateral ventricle (TH) may be required during temporal lobe and ambient cistern surgery. Most available anatomic landmarks for TH localization are based on adjacent cortical landmarks that are inherently variable or subtle. This study aimed to localize the anterior tip of the TH relative to adjacent bony landmarks. Methods The TH was exposed on 21 sides of 11 cadaveric heads via removal of the middle temporal gyrus. Two lines were defined: (1) a perpendicular line to the zygomatic arch projected from the anterior concavity of the posterior zygomatic root (line A), and (2) a parallel line passing through the anterosuperior corner of the external auditory canal (line B). Sagittal distances from lines A and B to a parallel line passing through the anterior recess of the TH (line H) were measured. Results Mean (standard deviation) distances from lines A and B to line H were 13.3 (2.5) mm and 11.9 (2.2) mm, respectively. Line H was at 53% (8%) of the line A–line B interval measured from line A. The best way to search for the TH was to start approximately 15 mm posterior to line A and progress posteriorly such that a more posteriorly located TH tip would not be missed. Conclusions The zygomatic-meatal landmark is a reliable tool to localize TH during various approaches. It is independent from the approach trajectory. This landmark may be used as an ancillary tool in conjunction with other cortical landmarks and image guidance.

Background Rosette-forming glioneuronal tumors (RGNTs) with multifocal growth throughout the ventricular system are extremely rare, and only 1 case of RGNT with dissemination limited to supratentorial ventricles has previously been reported. Recent evidence based on molecular data suggest that low-grade glioneuronal tumors (GNT) involving the septum pellucidum and the lateral ventricles, with either dysembryoplastic neuroepithelial tumor-like or RGNT-like features, may belong to a neuropathologic entity distinct from cortical dysembryoplastic neuroepithelial tumor and “typical” fourth ventricle RGNT, respectively. Given their rarity, the classification of these neoplasms is still uncertain and their clinicopathological and radiological aspects are only partially known. Case Description A 24-year-old male presented a GNT with RGNT-like morphological features centered in the septum pellucidum with multifocal masses occupying the lateral ventricles and the third ventricle with extraventricular infiltration of the frontal lobe. The patient underwent subtotal resection and 4 years follow-up. The clinicopathological and radiological features of the neoplasm are discussed. Conclusions Advanced magnetic resonance imaging (magnetic resonance spectroscopy and perfusion-weighted imaging) may provide valuable information in the differential diagnosis between rare GNTs and other more frequent intraventricular neoplasms. In the present case, the enhancing remnant portion of the tumor showed remarkable contrast enhancement variability during the follow-up with slow in situ progression. However, available data suggest that spontaneous contrast enhancement “fluctuations” over time in RGNT may not represent a reliable indicator of tumor behavior.

Objective Decompressive craniectomy (DC) has been advocated as a lifesaving procedure in management of patients with raised intracranial pressure due to malignant ischemic stroke (MIS). The aim of this study was to identify comparative radiologic parameters after DC to predict functional outcome at 6 months in patients with MIS. Methods A retrospective analysis (2015–2018) of patients (median age 54 years; range, 29–80 years) with MIS who underwent postoperative computed tomography within 24 hours of DC was performed. Multivariate regression analysis was computed to predict clinical outcome at 6 months based on the Glasgow Coma Outcome Scale Extended. Results With median National Institutes of Health Stroke Scale score of 20 (range, 3–33), mean preoperative stroke volume was 250 ± 75 cm3. Median Glasgow Coma Outcome Scale Extended score at 6 months was 4. Multivariate regression analysis showed that the comparative radiographic characteristics of absence of effacement of cortical sulci (odds ratio 2.88; 95% confidence interval, 1.22–20.71; P = 0.02), absence of hemorrhagic transformation (odds ratio 1.09; 95% confidence interval, 1.99–12.89; P = 0.03), and absence of compression of lateral ventricles (odds ratio 3.75; 95% confidence interval, 1.28–22.4; P = 0.05) on postoperative computed tomography scan were significant independent predictors of good functional outcome (Glasgow Coma Outcome Scale Extended score 5–8). Conclusions The comparative radiographic characteristics of absence of effacement of cortical sulci, hemorrhagic transformation, and compression of the lateral ventricles after DC in patients with MIS bore a significant relationship to predicting clinical outcome at 6 months.

Background The rosette-forming glioneuronal tumor (RGNT) is a rare World Health Organization grade I tumor, most often originating in the fourth ventricle and characterized by a predominant glial component, as well as a neurocytic component. Despite its benign grading, there are a few documented cases of RGNT displaying more aggressive behavior with malignant characteristics. Case Description Herein, we describe a uniquely aggressive presentation of RGNT in a 49-year-old man initially presenting with obstructive hydrocephalus with lesions in the right frontal lobe, fourth ventricle, and left lateral ventricle. The patient was found to have 2 distinct intracranial entities: a right frontal meningioma and disseminated intraventricular RGNT. He underwent an anatomically limited resection of the fourth ventricular lesion with fourth ventricle−to-subarachnoid space shunting. His disease progressed thereafter, with diffuse intracranial dissemination and drop metastases in the lumbar spine. He was treated with craniospinal radiation and remains on palliative care 5 months after completion of radiotherapy. Conclusions This case supplements and complements the handful of published cases available documenting the evolution of a particularly aggressive case of disseminated RGNT.

Background Surgical resection remains the standard treatment for most giant pituitary adenomas (GPAs). The selected surgical approach for these complex lesions depends mainly on their extension. Single approaches may be limited in some cases presenting with invasion into multiple compartments, thereby limiting extent of resection. Methods We report a series of patients with GPA operated on through a combined approach involving an endoscopic endonasal transsphenoidal approach and a tubular retractor-assisted transventricular approach, describing the technique, its indications, limitations, and outcomes. Baseline and postoperative clinical, functional, and morphologic variables were documented up until each patient’s last follow-up visit. Results Five patients harboring tumors extending into the third and lateral ventricles were included. Mean extent of resection was 94.6%. Mean follow-up was 39.4 months. One patient presented with a growth hormone-secreting GPA, who achieved remission after repeat resection during follow-up. There were no intraoperative complications, and 1 patient required reoperation for cerebrospinal fluid leak repair. One patient received adjuvant radiotherapy, and 3 patients remained stable requiring no additional treatment. All patients maintained an adequate postoperative functional status. Conclusions The combined approach herein described may be a safe and effective option for some patients with GPAs extending into the third and lateral ventricles. An adequate patient selection is mandatory to exploit the benefits of each individual approach.

Background Mucormycosis of the central nervous system is an uncommon infection caused by saprophytic or parasitic fungi of the subphylum Mucormycotina and order Mucorales viz. Rhizopus, Mucor, and Rhizomucor. Isolated, chronic involvement of the central nervous system is a rare occurrence. To the best of our knowledge, isolated chronic ventricular involvement in an infant has not been reported previously. Isolated intracerebral mucormycosis is a disease of the immunocompromised patient, and to date only 6 cases have been reported in immunocompetent patients, including 2 pediatric cases. Case Description We present the case of an immunocompetent infant presenting with features of increased intracranial tension. He underwent cerebrospinal fluid diversion and was found to harbor mucormycosis on histopathologic examination of intraventricular debris. We also present a brief review of the relevant literature. Conclusions Although mucormycosis is an acute fulminant infection, chronic isolated cerebral cases are known in the immunocompetent patient. Patients also may present with isolated hydrocephalus, and hence fungal infection must be ruled out in all, especially if a shunt is warranted.

The contralateral interhemispheric transprecuneus approach (CITP) and the supracerebellar transtentorial transcollateral sulcus approach (STTC) are 2 novel approaches to access the atrium of the lateral ventricle. We quantitatively compared the 2 approaches.Both approaches were performed in 6 sides of fixed and color-injected cadaver heads. We predefined the 6 targets in the atrium for measurement and standardization of the approaches. Using a navigation system, we quantitatively measured the working distance, cortical transgression, angle of attack, area of exposure, and surgical freedom.The distances from the craniotomy edge to the posterior pole of the choroid plexus of the CITP (mean ± standard deviation, 67 ± 5.3 mm) and STTC (mean, 57 ± 4.0 mm) differed significantly (P0.01). Cortical transgression with the CITP (mean, 27 ± 2.8 mm) was significantly greater than that with the STTC (mean, 21 ± 6.7 mm; P = 0.03). The CITP showed a significantly wider rostrocaudal angle of attack than that with the STTC (P = 0.01). The STTC showed a significantly wider mediolateral angle (P0.01). No significant difference was found for surgical freedom of any target except for point E, for which the CITP was larger. The exposure area did not differ significantly between the 2 approaches (P = 0.07).Both approaches were feasible for accessing the atrium. The STTC provided a shorter working distance and wider mediolateral angle, CITP provided a wider rostrocaudal angle of attack and better exposure and maneuverability to the anterior and superior atrium. In contrast, the STTC was more favorable for the inferior and posterior regions.

Background Primary intracranial squamous cell carcinoma (PISCC) is extremely rare, and most cases are caused by malignant changes in an epidermoid cyst or a dermoid cyst. We report a case of intracranial squamous cell carcinoma (SCC) that arose without a preexisting tumor. In addition, the literature on PISCC is reviewed. Case Description A 20-year-old man presented with a 4-day history of headache. Magnetic resonance imaging of the brain showed a heterogeneous and irregularly marginated solid-cystic lesion in the left lateral ventricle, which enhanced dramatically. The patient underwent removal of the lesion, and a postoperative histologic examination showed SCC. The patient did not undergo postoperative radiotherapy and was admitted to the hospital again 40 days later because of dizziness, right lower extremity pain, and difficulty in bending. Computed tomography showed hydrocephalus. The cerebrospinal fluid examination confirmed an intracranial infection. The patient was discharged after treatment. The patient survived for 9 months from the onset of the disease. Conclusions Most cases of PISCC arise from the malignant transformation of epidermoid cysts. However, SCC arising de novo is even less common. Although rare, the malignant transformation of intracranial epithelial cysts has a poor prognosis. Future prospective trials are necessary to evaluate the optimal treatment modality for patients with PISCC.

Introduction The pathophysiology of normal-pressure hydrocephalus and the correlation with its symptomatology is not well understood. Objective To monitor and evaluate the enlargement patterns of the ventricular system for each ventricle and its correlation with the presenting symptoms. Methods Bilateral kaolin injection into the subarachnoid space overlying the cranial convexities was done in 18 adult rats. Magnetic resonance imaging was performed on an 11.7-T scanner 15, 60, 90, and 120 days after injection. Volumes of the ventricular system were measured for each ventricle and correlated with biweekly behavioral findings. Results There was a progressive increase in the ventricular volume for the lateral ventricles since day 15 in the kaolin-injected animals. There was a nonsignificant trend in volume growth for the third ventricle, but its enlargement was synchronous with the lateral ventricles. No significant change for the fourth ventricle. No symptoms were detected in the first 60 days. Association was found between the ventricular volume and locomotor changes. In addition, the odds of locomotor symptoms increased by 3% for every additional cubic millimeter of volume in the left (P < 0.001) and right (P = 0.023) ventricles, and for the total magnetic resonance imaging volume by 1% (P = 0.013). Conclusions Expansion of the lateral ventricles maintained similar proportions over time, accompanied by a synchronous third ventricular expansion with less proportion and a nonsignificant fourth enlargement. Lateral ventricles enlarged most in those animals that were to develop late locomotor deterioration. Further research using this animal model combined with different radiologic imaging techniques, such as diffusion tensor imaging and perfusion studies, is recommended.

Background Intracranial arachnoid cysts (ACs) are generally benign fluid-filled cysts with a prevalence of 0.5%–2.7%. They can be treated through craniotomy with cyst removal, endoscopic fenestration, or cystoperitoneal or ventriculoperitoneal shunting. However, the outcome of these treatments has not been completely satisfactory. Cystoventricular shunting was described as an alternative method for the treatment of intracranial ACs in children in 2003. In the present report, we have described the outcomes of cystoventricular shunting in adults with symptomatic intracranial ACs. Methods A total of 24 patients with symptomatic ACs underwent cystoventricular drainage from 2012 to 2019. The most common symptom preoperatively was headache, followed by dysphasia, motor weakness, memory loss, seizures, and balance disturbances. After radiological evaluation, a ventricular catheter was placed in the AC and another in one of the lateral ventricles and connected extracranially after subgaleal tunneling using a straight metal connector. Results At 3–6 months of postoperative follow-up, 21% of patients were asymptomatic and 42% showed improvement in clinical symptoms. No patient had experienced impairment or progression of symptoms postoperatively. Three patients had required revision of the catheters and one patient had developed a postoperative superficial skin infection without signs of deeper infection. Conclusions Cystoventricular drainage seems to be an effective, reliable, and safe procedure to treat intracranial ACs when fenestration to the basal cisterns is not possible.

Background Aneurysms associated with brain arteriovenous malformations (AVMs) represent a hemorrhage risk in addition to that of the AVM nidus. In high-risk or unresectable cases, targeted treatment of an aneurysm causing hemorrhage may effectively decrease future hemorrhage risk. The objective of this report is to describe our series of patients with intraventricular AVM-associated aneurysms treated surgically. We highlight technical nuances of the surgical approaches to aneurysms in the lateral and third ventricles. Methods A retrospective review was performed of patients in whom an intraventricular aneurysm rupture was responsible for hemorrhage. In each patient, the aneurysm was excluded surgically via an interhemispheric approach, including transcallosal, transchoroidal, or transcingulate corridors. Aneurysm, AVM characteristics, surgical approach, and outcomes were reviewed. Results Six patients were included in the series. In 5 patients, the disease was located on the left and approached from the right. Aneurysms were located in, or projecting into, the lateral ventricle in 4 patients (transcingulate approach) and in the third ventricle in 2 patients (transchoroidal fissure approach). The aneurysm was clipped in 1 patient and resected in 5 patients. The associated AVM was resected in 2 patients. In all patients, the surgical approach allowed adequate treatment of the aneurysm without new neurologic morbidity. No patients experienced recurrent intraventricular hemorrhage during follow-up. Conclusions Ruptured intraventricular aneurysms associated with brain AVMs can be treated surgically to reduce the risk of rebleeding in patients in whom the aneurysms are not accessible to endovascular treatment and in which the AVM nidus may not be safely resected.

Background Cannulation of lateral ventricles via a posterior approach is a common neurosurgical procedure. It is often believed that a single entry and fiducial point applies to all. No importance is given to skull shape variations, which can lead to wrong shunt positions and revisions. Objective A virtual-reality study was conducted to find the ideal entry point, ideal forehead fiducial point, and ideal angulation of the ventricular catheter and variations in these with changes in skull shapes. Methods Fifty human cadaveric skulls were used to measure anteroposterior (AP) diameter and width and to classify shape of skulls into 4 types. Hydrocephalus (100 cases) and normal magnetic resonance images (50 cases) were studied from a PACS (Picture Archiving and Communication System) database. An Osirix DICOM Viewer (3.9.4) was used to reconstruct the images and estimate the ideal, 90°, and midline shunt trajectory and correlate the same with AP/width ratios and skull shapes. Results Contrary to popular practice, the vertical distance from the inion for ideal trajectory placement was 4 cm in all shapes and ratio groups for hydrocephalus and nonhydrocephalus cases, respectively. As the AP/width ratio increases, the fiducial needs to be placed at a higher distance from the nasion and the distance of the entry point also increased from the inion. A rounder or more dolichocephalic skull dictates a 90° approach to be better, especially as the first pass. Conclusions No magical external entry point uniformly applicable for all cases exists. Hence, there is a need to classify skulls according to shapes/ratios and to use a tailored approach for a freehand pass to cannulate the ventricles.

Background Bilateral occlusion of the foramen of Monro with aqueductal stenosis is a rare entity. Only 1 previous case has been reported in the literature. Case Description We present a 25-year-old female who presented with chronic headache of 7 years duration. Neurologic examination revealed only papilledema. Imaging showed symmetrical dilation of both lateral ventricles with mild dilation of the third ventricle and a normal fourth ventricle, suggesting occlusion of both foramina of Monro with membranous web formation in the upper part of the aqueduct. There was tonsillar herniation without syrinx. She underwent neuroendoscopic foraminoplasty, septostomy, and third ventriculostomy. The patient experienced total relief of headache and showed reduced volume of both lateral ventricles at follow-up. Conclusions Bilateral occlusion of foramen of Monro with aqueductal stenosis and tonsillar herniation is rare cause of obstructive hydrocephalus, and can be managed effectively with neuroendoscopic procedure.

Background Entrapment of the temporal horn, known as isolated lateral ventricle (ILV), is a rare type of noncommunicating focal hydrocephalus, and standard treatment has not been established. We report 2 cases of endoscopic surgery for ILV and highlight the anatomic surgical nuances to avoid associated surgical risks. Case Description The first patient presented with recurrent ILV following initial shunt placement for ILV, owing to shunt malfunction. In the second patient, ILV recurred secondary to choroid plexus inflammation caused by cryptococcal infection. Endoscopic temporal ventriculocisternostomy was effective in both cases. However, in the second case, the choroidal fissure was fenestrated, which led to cerebral infarction in the territory of the choroidal artery zone, attributed to damage of the branches of the choroidal segment of the anterior choroidal artery. Conclusions Although endoscopic temporal ventriculocisternostomy is considered a safe and less invasive procedure for treatment of symptomatic ILV, the technique is still associated with risks. To avoid complications, it is necessary to be familiar with the anatomy of the choroidal arteries and the pertinent endoscopic intraventricular orientation. Additionally, sufficient experience is required before it can be recommended as the treatment of choice.

Midline shift (MLS) has been a known predictor for prognosis after spontaneous intracerebral hemorrhage (ICH), whereas it is secondary to lateral ventricular compression. In this study, we investigated whether lateral ventricular volume (LVV) asymmetry caused by ventricular compression was independently associated with poor outcome of ICH.We retrospectively studied clinical patients with spontaneous ICH from January 2010 to January 2017. LVV was calculated using slicer software. LVV ratio (LVR) was then determined to quantitatively evaluate LVV asymmetry, and its relationship with poor outcome was tested by logistic regression model. Receiver operating characteristic (ROC) curve analysis was performed to identify the optimized baseline LVR cutoff point to predict poor outcome.188 patients were included, of whom 41% (77/188) experienced a poor outcome. Multivariate logistic regression analysis identified baseline LVR as an independent predictor for poor outcome after ICH. The predictive value of baseline LVR was confirmed by ROC analysis (area under the curve = 0.742; P0.001). The optimized baseline LVR cutoff point was 3.7, with a sensitivity of 64.9% and specificity of 80.2%. Using LVR3.7 as an exposure factor yielded an odds ratio of 7.49 (P0.001), and a risk ratio of 2.98 (P0.001).LVV asymmetry was associated with clinical prognosis after ICH, and high LVR (3.7) might independently predict poor outcome.

Background Complex hydrocephalus affecting lateral and fourth ventricles separately is occasionally managed with cerebrospinal fluid diversion via supratentorial and infratentorial ventricular catheters. The optimal configuration to reduce complications is currently unknown in adults. We describe a consistently similar clinical presentation of patients with complex hydrocephalus and a fourth ventricle separately drained by infratentorial shunt insertion. Methods This was a retrospective single-center case series. Medical notes were reviewed for clinical presentation, brain imaging, and neurophysiologic tests results. All patients underwent intracranial pressure monitoring (ICPM). Outcomes were determined by ventricular appearance on brain imaging computed tomography and symptomatic improvements postoperatively. Results Five adult patients referred to the hydrocephalus service had separate infratentorial and supratentorial shunt systems. A common clinical presentation was observed, including lower motor neuron facial palsy (confirmed with electrophysiology), ophthalmoplegia, dysarthria, impaired gait headache, and nausea. We refer to this as transtentorial distortion syndrome. Twenty-four-hour ICPM demonstrated clear low pressures. All patients underwent shunt revision connecting the transtentorial shunts via a Y-connector and the addition of a distal valve. All subjects had improved ventricular appearance on computed tomography scans post revision, and normalization of ICPM was observed. In the follow-up period of 6 months, no patient required further shunt revision. Conclusion To prevent transtentorial distortion syndrome, supratentorial and infratentorial shunt constructs in adults with encysted fourth ventricles should be similar to the shunt systems widely known in the pediatric population with Dandy-Walker syndrome (i.e., joint output to a single valve distal to the connection of the 2 proximal drainage catheters).

Background Collateral artery aneurysms are a source of intracranial hemorrhage in moyamoya disease. Several reports have shown that surgical revascularization leads to the obliteration of collateral artery aneurysms. However, its effect on the prevention of rebleeding has not been established, and the optimal timing of the operation remains unclear. The purpose of the present study is to evaluate the effects of surgical revascularization and to investigate the optimal operation timing in patients with moyamoya disease who have ruptured collateral artery aneurysms on the ventricular wall. Case Description Two patients with moyamoya disease who presented with intraventricular hemorrhage caused by rupture of collateral artery aneurysms on the wall of the lateral ventricle are presented here. In both cases, the aneurysms reruptured approximately 1 month after the initial hemorrhage. Both patients successfully underwent superficial temporal artery–middle cerebral artery anastomosis combined with indirect bypass in the subacute stage. The aneurysms decreased with the development of collateral circulation through the direct bypasses, and rebleeding did not occur after the surgery. Conclusions Because ruptured collateral artery aneurysms on the wall of the lateral ventricle in moyamoya disease are prone to rerupture within 1 month, surgical revascularization may be recommended as soon as the patients are stable and able to withstand the operation.

OBJECTIVE This study aimed to characterize pyramidal tract shift in different regions of the brain during glioma resection and its association with head position and tumor location. METHODS From 2008-2013, 14 patients presenting at the National Neuroscience Institute with high-grade glioma (World Health Organization III or IV) underwent preoperative and intraoperative diffusion tensor imaging. A novel method of placing landmarks along the preoperative and intraoperative tracts, with anterior commissure as the origin, was used to determine pyramidal tract shift. Shift was evaluated in x (lateromedial), y (anteroposterior), and z (craniocaudal) directions for 3 brain regions: brainstem, around third and lateral ventricles, and above ventricles. Shift radius is calculated as the distance between preoperative and postoperative landmarks. RESULTS Mean shift radius was 2.72 ± 0.55, 2.98 ± 0.53, and 4.04 ± 0.58 mm at the brainstem, third and lateral ventricles, and above the ventricles, respectively (P

Background Intraventricular meningiomas comprise 0.5%–3% of intracranial meningiomas. They often cause obstructive hydrocephalus and commonly are treated with surgical resection or stereotactic radiosurgery. Objective To describe the surgical approaches and resection techniques needed to approach intraventricular tumors while highlighting the eloquent anatomy and blood supply surrounding the ventricular system to avoid neurological injury. Methods Two cases of left atrial intraventricular meningiomas that were complicated by postoperative lateral geniculate nucleus ischemia and resultant temporary contralateral quadrantanopia are described. The safe surgical approaches to the atrium of lateral ventricles as well as the anatomy and blood supply to the lateral geniculate nucleus and optic radiation are discussed and illustrated. Results In both cases, the patients had complete resection of their tumors. They both ultimately made a good recovery after transient visual deficits. These cases provide useful demonstrations of eloquent anatomy of the ventricular walls and visual pathway anatomy. Conclusions Care must be taken to avoid visual pathways along the lateral ventricle wall and the nearby arterial supply of the lateral geniculate nucleus from the choroidal arteries when resecting intraventricular tumors.

Objective We sought to report the operative techniques of the endoscopic supracerebellar transtentorial approach (ESTA) to the atrium of the lateral ventricle, especially focusing on the role of the endoscope and analyzing optically related issues. Methods A retrospective data review was performed on 5 patients with lesions in the atrium of the lateral ventricle undergoing the ESTA. The patients were positioned in the three quarters prone position, and a paramidline linear incision was used. After performing a suboccipital craniotomy extending immediately above the transverse sinus and tentorium incision with precisely neuronavigation, corticotomy in the posterior mediobasal temporal region created a corridor to the tumor. All of the procedures were performed with an endoscope in a pneumatic arm holder. The preoperative and postoperative perimetry test and diffusion tensor imaging fiber tracking of the optic radiations were compared and analyzed. Results Three patients had meningiomas, and 2 patients had high-grade gliomas in the atrium. The meningiomas were totally removed, and the gliomas were subtotally resected. One patient with glioblastoma died 2 months later after surgery because of the tumor progression; the remaining 4 patients had a visual field deficit without any other neurologic complications. The endoscope improved the surgical viewing angle, which was restricted by the microscope and slope of the tentorium. Conclusions ESTA is an alternative route to the atrium of the lateral ventricle. However, the collateral sulcus, which is highly relied on in neuronavigation, is illegible in the limited area. And the visual field deficit remains the primary challenge with this approach.

Objective We previously disclosed that damage to the subependymal arteries (SEAs) caused by coagulation of the choroid plexus at the atrium can result in infarction within the lateral posterior choroidal artery territory, followed by hemiparesis. The present study describes the intraoperative anatomical findings of the SEAs and choroid plexus at the atrium, which were verified only by a few cadaveric studies. Methods Locations of the SEA and descending motor pathway were determined with the neuronavigation system and subcortical electrical stimulation in 8 cases of periatrial brain tumor. Indocyanine green videoangiography was performed to verify the blood flow in the choroid plexus and SEAs. Results Intraoperative visualization of the SEAs was performed successfully in all patients. The neuronavigation system and subcortical electrical stimulation mapping demonstrated that these SEAs penetrated into the descending motor pathway. Indocyanine green depicted the blood flow of the SEAs entering the wall of the lateral ventricle and adjacent brain parenchyma. The blood flow directions between the SEAs and choroid plexus were not uniform, because the SEAs were filled ahead of the choroid plexus in 3 cases, whereas the choroid plexus was filled first in the other 2 cases. Conclusions Manipulations to the inner side of the choroid plexus at the transition from the atrium to the body of lateral ventricle can damage the SEAs. Not only coagulation of the SEAs themselves, but also coagulation of choroid plexus itself may reduce the blood flow in the SEAs, resulting in ischemic complications at descending motor pathway.

Background Intraventricular tumors present difficult challenges to the neurosurgeon. Neurosurgeons have begun to explore the possibilities of using the endoscope in the radical resection of solid intraventricular lesions. There is a steep learning curve when dealing with such lesions with an endoscope. Objective The aim of this study was to create a laboratory training model for neuroendoscopic surgery of intraventricular lesions guided by the navigation system. We believe this technique is more reliable than the traditional approach using contrast injection with C-arm x-ray guidance. Materials and Methods Five formalin-fixated, latex-injected cadaveric heads were used. The arterial system was injected with red latex through the common carotid arteries, and the venous system was injected with blue latex through the internal jugular veins at the C6 vertebral level. The contrast-enhancing tumor polymer, Stratathane resin ST-504-derived polymer (SRSDP), was injected into the lateral ventricle via Frazier's point under direct endoscopic visualization and real-time neuronavigation guidance. When navigation was used for trajectory planning, the peel-away sheath was registered using a frameless navigational system (BrainLAB, Feldkirchen, Germany). A questionnaire was distributed to all participants in an endoscopic cadaveric course in which the models were used to evaluate the endoscopic tumor model. Results Neurosurgeons participating in the course performed an endoscopic approach to resect the intraventricular tumor model through an ipsilateral frontal burr hole. The properties of the SRSDP mixture could be manipulated through varying concentrations of the materials used, in order to reach the desired consistency of a nodular solid lesion and possibility for piecemeal resection. The tumor model allowed participants to compare between normal and pathologic endoscopic anatomy in the same cadaveric head. Conclusion This injectable tumor model with the combination of neuroendoscopy and navigation can improve the accuracy of the endoscopic approach and minimize the risk of cadaveric brain specimen damage that in return augments the feeling of lifelike conditions. Using this endoscopic injectable tumor model technique can assist neurosurgeons' preparation for the challenges associated with an endoscopic piecemeal resection of a solid lesion in the lateral or third ventricle.

Objective The objective of this study was to compare transcortical and posterior interhemispheric approaches to the atrium using a combined approach of white matter fiber dissections and magnetic resonance (MR) tractography. Methods Ten cerebral hemispheres were examined and dissected from the lateral-to-medial surface and from the medial-to-lateral surface, with special attention to the white matter tracts related to the atrium. MR tractography was used to show the relationship of three-dimensional white matter fibers with the atrium of the lateral ventricle and to compare with cadaveric dissection results. Results The atrium was related laterally to the superior longitudinal fasciculus II and III, middle longitudinal fasciculus, arcuate fasciculus, vertical occipital fasciculus, and sagittal stratum. Medially, it is related to the superior longitudinal fasciculus I, cingulum, sledge runner, and forceps major. Conclusions A combined approach of cadaveric white matter fiber dissections and MR tractography were used to describe the main white matter tracts related to the posterior interhemispheric approach and the transcortical approach, providing an in-depth understanding of the three-dimensional anatomy of white matter fibers and the atrium. In the present study, among approaches examined, the posterior interhemispheric parasplenial transprecuneus approach placed fewer eloquent tracts at risk; however, traversing the sledge runner and the forceps major is unavoidable by this approach.

Background Resective surgery remains the main treatment option for most patients with craniopharyngiomas. Understanding of the microsurgical anatomy of the sella and suprasellar region and its relationship with these tumors is necessary to achieve effective surgical treatment and minimize complications. In this article, we review the surgical anatomy related to craniopharyngiomas and divide it in 5 compartments according to tumor extension. Methods Endoscopic and microsurgical dissection were performed in 3 freshly injected cadaver heads at the Weill Cornell Surgical Innovations Laboratory (New York, New York, USA) and at the Surgical Skills Center at Mount Sinai Hospital (Toronto, Ontario, Canada). Tumor extension was classified as 1) inferomedial or sellar, 2) superomedial or suprasellar, 3) lateral or sylvian, 4) posterior or interpeduncular/prepontine, and 5) intraventricular. The selection of surgical approaches is discussed based on the anatomic nuances of each these regions. In addition, we reviewed the literature regarding previous anatomic classifications for resection of craniopharyngiomas. Results Different approaches should be considered according to tumor extension into different compartments. Purely sellar tumors are amenable to endoscopic transsellar approaches, whereas those with a suprasellar extension require an extended transtuberculum approach. In some of those patients, a narrow chiasm-pituitary window may block access to the tumor and a transcranial translamina terminalis approach may be favored. Tumors occupying the interpeduncular fossa may pose a significant challenge for an endoscopic endonasal approach and transcranial approaches. Transcavernous approaches and anterior and posterior clinoidectomies may be required for adequate exposure in such patients. Translamina terminalis and/or transcallosal approaches are recommended for resection of purely intraventricular tumors. Tumors extending into the lateral compartment should be considered for transcranial frontotemporal approaches. Conclusions The understanding of such anatomic nuances aids in the selection of the most appropriate surgical approach and in the prevention of potential complications. Because most craniopharyngiomas are midline lesions, the endoscopic endonasal approach represents an excellent approach for most of those tumors. However, transcranial approaches should be considered for tumors with extension into the lateral compartment and for selected tumors involving the ventricular compartment (purely intraventricular tumors and those with extension to the foramen of Monro and/or lateral ventricles).

Objective Lateral intraventricular anaplastic meningiomas (LIAMs) are rare lesions. The aim of this study is to clarify clinical and radiologic characteristics and the optimal treatment strategies of LIAMs with long-term follow-up. Methods From September 2008 to September 2017, 5 patients with LIAM were enrolled in our study. The clinical profiles, radiologic features, treatment strategies, and outcomes were retrospectively analyzed. Results Five patients (all female; mean age, 48.8 years; range, 33–61 years) were included in this study. The most frequent symptoms were those related to increased intracranial pressure. Mean duration of symptoms was 6.7 months (range, 2 weeks–2 years). The average tumor size was 4.98 cm at the maximal diameter (range, 3.0–6.2 cm). All were confirmed with a diagnosis of anaplastic meningioma. Gross total resection was achieved in all 5 patients. All patients experienced improvement of symptoms. Recurrence and progression were identified in only 2 patients. At the last follow-up, the mean recurrence-free survival was 13 months (range, 7–21 months) and the mean overall survival was 16.25 months (range, 8–21 months). One patient was lost to follow-up. Conclusions Female and right trigone area predominance were found in our case series. Shorter duration of symptoms, irregular tumor shape, peritumoral edema, and heterogeneous enhancement may indicate an aggressive feature. Maximal safe resection followed by radiation therapy may be the best strategy for patients with LIAM. Long-term clinical follow-up and serial imaging are recommended.

To assess usefulness and limitations of flexible fiber carbon dioxide (COWe reviewed a series of 9 patients treated with microsurgical resection of intraventricular tumors using a flexible fiber COGross total resection was achieved in 6 cases and subtotal resection in the remaining 3. Three patients had pulmonary complications treated without clinical sequelae. No laser-related complication was described. Mean utility score observed was 4.2 (range 3-5) during approach, 2.8 (range 2-4) during tumor dissection; and 3.3 (range 2-5) during tumor debulking. Main limits were low hemostatic effect and inefficiency versus calcified and highly vascularized tumors.The CO

Objective Patients with hydrocephalus secondary to third ventricular colloid cysts can require bilateral external ventricular drain (EVD) placement while awaiting surgery. However, some patients could develop auto-fenestration of the septum pellucidum (AFSP) and only require 1 EVD. We evaluated our experience with bedside iohexol ventriculography and staged EVD placement for patients with obstructive hydrocephalus. Methods We retrospectively identified 34 patients who had been treated for third ventricular colloid cysts (2013–2016). The preoperative and postoperative data, including age, sex, colloid cyst size, preoperative hydrocephalus, preoperative EVD placement, preoperative iohexol ventriculography, operative approach, intraoperative findings, and postoperative ventriculoperitoneal shunt requirements, were reviewed. Results Hydrocephalus was found in 23 patients (68%) on initial presentation. Nine patients (26%) had EVDs placed before surgery. Six patients (18%) underwent iohexol ventriculography after insertion of a right-sided EVD. Five patients (15%) demonstrated no evidence of ventricular communication. Four patients (67%) required left-sided EVD placement. One patient (17%) had robust communication between the lateral ventricles after intraventricular iohexol injection, which was managed with a single EVD. AFSP was observed during surgical resection of this patient’s colloid cyst. One other patient who did not undergo preoperative EVD placement was noted to have AFSP intraoperatively, resulting in 2 of 34 patients (6%) with AFSP in our series. Conclusions A subset of patients with obstruction at the foramina of Monro can develop AFSP. Iohexol ventriculography after unilateral EVD placement allows clinicians to assess for the presence of AFSP and identify patients who can be treated with a single EVD before surgery.

In some rare cases, long-standing hydrocephalus can cause "high-pressure" cerebrospinal fluid fistulas. We report the case of a young overweight woman with rhinorrhea secondary to hydrocephalus with a fistula into the frontal sinus. Brain imaging studies revealed aqueduct stenosis. Ventriculocisternostomy treated the hydrocephalus but did not cure the rhinorrhea, and additional multilayer surgical skull base repair was necessary. In these cases, the CSF leakage acts as a safety valve, and closure will worsen the patient's condition if the causative lesion has not been treated first. Moreover, identifying the exact location of the fistula can be challenging and will usually require high-resolution bone computed tomography.

Background Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. It has an indolent clinical course and favorable prognosis. Brain metastasis is uncommon and complicates about 0.1%–5% of PTCs. Metastasis to the choroid plexus of the lateral ventricles has been reported in 7 cases of thyroid malignancies, all of which were unilateral. Methods We report a case of a 52-year-old woman with a history of PTC who presented with severe headache, nausea and vomiting, right hemiparesis, and speech disturbance. Imaging studies depicted lesions in both lateral ventricles. Results The patient underwent microsurgical tumor resection. Histopathologic examination revealed choroid plexus metastasis from PTC. Conclusions Metastases to the choroid plexus from extracranial tumors are very rare, with only a few cases reported thus far. A demographic analysis of these cases suggests there may be a tropism of some extracranial carcinomas, such as renal cell carcinoma, for choroid plexus, especially in the lateral ventricles. We report the eighth case of choroid plexus metastasis, but it is the first bilateral one arising from thyroid cancer.

Background Giant cell ependymoma (GCE) is a rare primary central nervous system neoplasm. We report a case of GCE arising in the lateral ventricle. Case Description A 22-year-old female presented with generalized seizures. Magnetic resonance imaging demonstrated a diffuse, nonenhancing, multicystic mass centered in the atrium of the right lateral ventricle with extension throughout the frontal and temporal horns. An initial subtotal resection yielded the signature biphasic pattern of GCE. The dominant component contained pleomorphic, bizarre-appearing giant cells with low mitotic index, and a minor component comprised monomorphic, highly cellular, mitotically active cells that formed perivascular pseudorosettes. Array-comparative genomic hybridization showed copy number abnormalities consistent with chromosomal instability without evidence of RELA- or YAP1-fusion—features most often seen in posterior fossa ependymoma group B. Given expectedly poor radiation sensitivity, a second-look surgery was undertaken to minimize residual before proton beam radiotherapy. Literature Review Review of the literature identified 28 reported cases, with a median age of 34 and bimodal peaks at approximately 20 and 50 years of age, including 9 supratentorial, 5 infratentorial, and 15 spinal ependymomas. Two infratentorial cases involved the fourth ventricle; no cases arose from the third or lateral ventricles. Supratentorial tumors predominated in younger patients, whereas other locations were observed among older patients (21.6 vs. 46.3 years of age; P = 0.01). Cases with Ki-67 index ≥10% showed worse progression-free survival than those of Conclusion Although rare, GCE should be considered in the differential of young patients with atypical intraventricular lesions, particularly given that extent of resection is associated with increased survival and GCE is thought to be radiation resistant.

BACKGROUND: Glioblastomas have a poor prognosis, possibly because of a subpopulation of therapy-resistant stem cells within the heterogeneous glioblastoma. Because the subventricular zone is the main source of neural stem cells, we aimed at characterizing the subventricular zone using diffusion tensor imaging (DTI) to show subventricular zone involvement in glioblastoma.METHODS: We prospectively included 93 patients with primary glioblastomas who underwent preoperative DTI. The nonenhancing high fluid-attenuated inversion recovery (FLAIR) signal was used to describe the infiltrative tumor margin. We used a 5-mm margin surrounding the lateral ventricles to define the subventricular zone. The subventricular zone with high FLAIR was compared with the subventricular zone without high FLAIR, control high FLAIR outside the subventricular zone and control contralateral normal-appearing white matter. Normalized DTI parameters were calculated and compared between the different regions.RESULTS: The subventricular zone with high FLAIR showed increased isotropic p values compared with the subventricular zone without high FLAIR (t(126) = 3.9; P CONCLUSION: DTI data showed that the subventricular zone is involved in glioblastoma with increased isotropic p values in the subventricular zone with high FLAIR, indicating tumor infiltration.

Objective Lateral ventricular trigone meningioma is relatively rare and surgical resection is the main treatment strategy. It is a challenge to achieve total resection without any complication. We analyzed a series of cases using literature review. Methods Retrospective data was collected on patients who underwent surgical treatment for trigone meningioma at our department from 2007 to 2012. Results Forty-three patients were included (12 men, 31 women). The average age was 42.8 years old. The symptoms depended on tumor size and location; 38 had prominent symptoms. The preoperative neuroimaging help assess the entity, size, location, and blood supply of the tumor. All lesions were resected using the trans-sulcal temporal or parietal approach, with intraoperative ultrasound assistance. Total resection was achieved in all patients. Thirty-six patients had a ventricular drain, which was removed 1 to 14 days later. Of the patients having prominent symptoms, 31 had relief soon after the operation, the other 7 patients improved to some extent at long-term follow-up. Two patients developed intraoperative distant epidural hematoma, which was confirmed by ultrasound, and underwent hematoma evacuation immediately. Two patients were reoperated for extensive intracranial hypertension. Three patients developed localized hydrocephalus and 2 of those underwent ventriculoperitoneal shunt several months later and 1 patient had spontaneous relief. One patient had grade II meningioma and 2 had grade III; they underwent adjuvant radiotherapy. The follow-up period ranged from 2 to 71 months, with no recurrence. Conclusions Surgical resection, using the trans-sulcal approach with intraoperative ultrasound assistance, can achieve a high rate of total resection and a low rate of complication, promising a good prognosis. The management technique and the perioperative treatment have to be individualized.

Only a few cases of intraventricular hydatid cysts have been described. The camalote or water lily sign is described when there is detachment of the endocyst membrane, resulting in a floating appearance like a water lily. This sign has been described most commonly in hepatic cysts. Here, we describe the camalote sign in an iatrogenically ruptured intraventricular hydatid cyst. Rupture of an intraventricular hydatid cyst poses the threat of widespread dissemination and is described in our case.

Background Acute hydrocephalus (ventricular enlargement within 72 hours) is a common complication in patients with aneurysmal subarachnoid hemorrhage (SAH). Cerebrospinal fluid (CSF) secretion may be increased in the early phases of SAH, but it has not been proved definitively. We studied the histologic features of choroid plexus (CP) in the early and late phases of SAH. Methods This study was conducted on 20 rabbits, with 5 rabbits in the control group, 5 rabbits in the sham group, and 10 rabbits in the SAH group. In the SAH group, five of the animals were decapitated after 2 days of cisternal blood injections, and the other five animals were decapitated after 14 days of injections. The CP of lateral ventricles were obtained from coronary sections of brains at the level of the temporal horns of the lateral ventricles. Sections were stained with hematoxylin and eosin and Masson trichrome for SAH-related damage and examined stereologically to discern water-filled vesicles, which were counted. Sections were compared statistically. Results The mean numbers of water vesicles were different after SAH between the early decapitated group (group III) and the late decapitated group (group IV). The mean numbers of water vesicles were 2.80 (±0.05) in the control group (group I), 2.76 (±0.02) in the sham group (group II), 14.68 (±0.06) in the early decapitated group (group III), and 4.78 (±0.13) in the late decapitated group (group IV). Total number of fluid-filled vesicles of CP was also assessed stereologically; the total numbers were 840 (±16) in group I, 828 (±7) in group II, 4404 (±19) in group III, and 1434 (±41) in group IV. The numbers of water-filled cisterns were significantly increased in the early phases of SAH ( P Conclusions In SAH with aneurysm rupture, increased CSF secretion seems to be triggered by hemorrhage in the early phase, but it is not possible in the late phase because of CP degeneration. In the early phase of hemorrhage, CSF secretion may be stimulated by the irritant receptor glossopharyngeal and vagal nerve endings, which innervate the healthy CP epithelium and arteries. Our findings may be accepted as being causative. It is likewise possible that CSF blockage per se leads to hydrocephalus, and the morphologic changes are sequelae that occur later in the course of disease. This is the first study to show the water vesicles of CP as a causative factor in the development of acute hydrocephalus after SAH.

Background The prevalent method of ventriculostomy placement is via freehand insertion to cannulate the ventricle at a 90° angle to the skull to get ideal placement. Our goal was to test the validity of this practice in patients without midline shift and with normal ventricular size. Methods This study was a virtual radiographic analysis of 3-dimensional data of skull and ventricular anatomy. Data were collected using thin-cut (1-mm) computed tomography scans of 101 randomly selected patients with normal ventricular anatomy. Virtual ventriculostomy trajectories were determined for entry from the right and left sides separately, going in at a 90° angle to the skull. Three-dimensional multiplanar reconstructions were performed using Osirix software to see where the catheter would end up within the brain. Results In our patient population, the mean bicaudate index was 0.14. Of the 202 perpendicular lines created from Kocher's point into the brain, 67.8% (137) of the virtual lines passed through the ipsilateral frontal horn of the lateral ventricle, 20.8% (42) passed through the contralateral ventricle, and 10.4% (21) did not pass through a ventricular space. A lower bicaudate index also leads to a greater misplacement even with a perpendicular trajectory. Pushing a catheter beyond an entry length of 6.5 cm if no cerebrospinal fluid flow has been obtained will not result in ipsilateral ventricular catheterization. Conclusions Our study concludes that not all catheters passed through Kocher's point using a perpendicular trajectory will end up in the ipsilateral frontal horn, and almost 10% of these catheters will be in a nonventricular space. In the instance in which a freehand pass fails to cannulate a ventricle, the safest alternative would be to make only minor adjustments to the perpendicular angle.

Background Access to the trigone of the lateral ventricle is challenging because of the deep location and the intimate relationships to eloquent areas. Methods A novel posterior interhemispheric transfalx transprecuneus approach for two meningiomas at the trigone of the lateral ventricle is described. Results The meningiomas were resected completely with good neurologic outcomes and no operative mortality. Conclusions The feasibilities and advantages of this novel approach are discussed.

Background A colloid cyst is a rare benign tumor. If indicated, surgical treatment can be realized using a microsurgical technique or an endoscopic technique. We report an uncommon complication of a third ventricle colloid cyst endoscopic removal. Case Description The cyst was incidentally discovered on computed tomography scan workup for mild head trauma in a 20-year-old male. Minor headache and minor memory loss were noted on clinical examination. Magnetic resonance imaging workup revealed obstructive hydrocephaly of the lateral ventricles associated with left uncal herniation. Surgery was uneventful. However, left oculomotor palsy was noted postoperatively. Workup revealed oculomotor nerve injury and isolated left mammillary body ischemia, secondary to worsened uncal herniation. This worsening might be caused by acute left ventricle hydrocephaly ascribed to interventricular foramen obstruction during cyst removal. Conclusion Therefore, in similar presentation, realizing septum fenestration before cyst removal should relieve the pressure in the lateral ventricles thus decreasing the risk of herniation.

Background Although neuroendoscope is widely used, endoscopic removal of intraventricular solid tumors has rarely been reported. Most reported procedures were performed with special endoscopic instruments through the endoscope's working channel—intra-axial endoscopic procedures. We report two cases of combined intra-/extra-axial endoscopic procedures—intraventricular solid tumor resection for subependymal giant cell astrocytoma. Methods In 2007, two patients with subependymal giant cell astrocytoma with a long history of tuberous sclerosis underwent solely endoscopic, minimally invasive intraventricular tumor resection. Through a precoronal transcortical approach, intra-axial endoscopic techniques were used to biopsy tumors. After a 1- to 1.5-cm in diameter corridor was formed inside the frontal lobes, extra-axial endoscopic techniques were used to explore the tumors and resect them. During extra-axial procedures, microneurosurgical instruments were used around the endoscope. Results In both patients, gross total resection of the tumors was achieved safely. Pathologic diagnoses were subependymal giant cell astrocytoma. There were no complications from surgery, and no neurological deficits. Patients were doing well and shunt free during the 8-month postoperative follow-ups. Postoperative magnetic resonance images showed minimal approach-related trauma along the surgical corridor. Conclusions In the present report endoscopic minimally invasive neurosurgery (EMIN) was defined as procedures in which the endoscope was used independently as the only optical device, for both illumination and visualization. Depending on the relationship between surgical instruments and the endoscope, EMIN was classified as intra-axial and extra-axial procedures. EMIN is a completive, safe procedure for intraventricular subependymal giant cell astrocytoma.

This study investigated whether functional neuronavigation can be used to remove lesions in the lateral ventricle while preserving patients' neurologic functionality.A total of 60 patients with lateral ventricular meningiomas were divided into study and control groups (n = 30 each). Diffusion tensor and blood oxygenation level-dependent functional magnetic resonance imaging were used for fiber tracking and eloquent cortex localization, respectively, in the study group. The surgical approach was based on coregistered data sets from 3-D lesion and brain structure reconstructions. Patients in the control group underwent anatomic neuronavigation-guided surgery. The patients' demographics, degree of resection, visual field, language score, movement, preoperative and postoperative Karnofsky Performance Status (KPS) scores, and surgical complications were recorded.Tumors were completely removed in both groups. Patients in the study group had a higher rate of visual field preservation than controls (P = 0.01). The two groups had similar motor and language functions after surgery, except that fewer cases of transient aphasia were observed in the former (P0.05). KPS scores for the study and control groups were 80 (70-80) and 70 (60-70), respectively (P0.01), at 2 weeks and 90 (80-100) and 85 (70-90), respectively (P = 0.022), at 3 months after surgery.Functional neuronavigation preserved neurologic functionality and was especially beneficial for protecting optical functionality and for the rapid recovery of patients.

Objective Wartime penetrating brain injury can result in deep-seated parenchymal and intraventicular shrapnel, bullets, and bone. Large fragments pose a risk of secondary injury from migration, infection, and metal toxicity. It has been recommended that aggressive removal of fragments be avoided. The goal of this study is to report our technique of minimally invasive removal of select deep-seated fragments using a tubular retractor system. Methods A retrospective review of our database of service members presenting with penetrating traumatic brain injuries incurred during Operations Iraqi Freedom and Enduring Freedom and treated at the Walter Reed Army Medical Center and the National Naval Medical Center was performed. Six individuals were identified in which the Vycor ViewSite retractor system (Vycor Medical, Boca Raton, Florida, USA) was used to remove a ventricular or deep intraparenchymal fragment. All patients were male and ranged in age from 21 to 29 years. Fragment location included the foramen of Monro; the atrium of the right lateral ventricle; parasagittally within the right occipital lobe; the occipital horn of the right lateral ventricle; the deep white matter of the dominant temporal lobe; and within the posterior right temporal lobe deep to the junction of the transverse and sigmoid dural venous sinuses. Fragments included in-driven bone, shrapnel from improvised explosive devices, and bullets. Results In all cases the fragment was successfully removed. No patient had worsening of their neurologic condition following surgery. Conclusion Deep parenchymal and intraventricular fragments can be safely removed using a tubular retractor system.