Longitudinal assessment of ventricular volume trajectories in early-stage schizophrenia: evidence of both enlargement and shrinkage.

BACKGROUND: Lateral ventricular enlargement represents a canonical morphometric finding in chronic patients with schizophrenia; however, longitudinal studies elucidating complex dynamic trajectories of ventricular volume change during critical early disease stages are sparse. METHODS: We measured lateral ventricular volumes in 113 first-episode schizophrenia patients (FES) at baseline visit (11.7 months after illness onset, SD = 12.3) and 128 age- and sex-matched healthy controls (HC) using 3T MRI. MRI was then repeated in both FES and HC one year later. RESULTS: Compared to controls, ventricular enlargement was identified in 18.6% of patients with FES (14.1% annual ventricular volume (VV) increase; 95%CI: 5.4; 33.1). The ventricular expansion correlated with the severity of PANSS-negative symptoms at one-year follow-up (p = 0.0078). Nevertheless, 16.8% of FES showed an opposite pattern of statistically significant ventricular shrinkage during ≈ one-year follow-up (-9.5% annual VV decrease; 95%CI: -23.7; -2.4). There were no differences in sex, illness duration, age of onset, duration of untreated psychosis, body mass index, the incidence of Schneiderian symptoms, or cumulative antipsychotic dose among the patient groups exhibiting ventricular enlargement, shrinkage, or no change in VV. CONCLUSION: Both enlargement and ventricular shrinkage are equally present in the early stages of schizophrenia. The newly discovered early reduction of VV in a subgroup of patients emphasizes the need for further research to understand its mechanisms.

Frequency of brain ventricular enlargement among patients with diabetes mellitus.

AIMS: To determine the prevalence of dilated ventricles and concomitant high blood glucose measures. METHODS: We retrieved blood glucose measures from the emergency department database and selected a subgroup of individuals having both the radiological marker Evans' index (EI) values and blood glucose measures. RESULTS: Out of 1221 consecutive patients submitted to axial Computed Tomography scans, a blood glucose measure was detected in 841 individuals. 176 scans (21 %) showed an EI > 0.30. According to the blood glucose categorization, diabetic patients were 104 (12 %), 25 of them (24 %) were dilated (mean EI 0.33). The age difference between dilated and not-dilated ventricles is about ten years in not-diabetic participants, whereas it is five years in diabetic participants. The age difference between dilated and not-dilated ventricles is about 10 years in diabetic men, whereas it zero in diabetic women. CONCLUSIONS: Pathological ventricular enlargement is more frequent in men and in the elderly. In diabetic patients (especially women), the cerebral ventricles enlarge faster than in non-diabetic individuals. Age, sex, and diabetes may interact in determining how cerebral ventricle size changes over time, especially in diabetic women, making routine brain imaging advisable in these patients after the age of 70 years.

Validating the accuracy of real-time phase-contrast MRI and quantifying the effects of free breathing on cerebrospinal fluid dynamics.

BACKGROUND: Understanding of the cerebrospinal fluid (CSF) circulation is essential for physiological studies and clinical diagnosis. Real-time phase contrast sequences (RT-PC) can quantify beat-to-beat CSF flow signals. However, the detailed effects of free-breathing on CSF parameters are not fully understood. This study aims to validate RT-PC's accuracy by comparing it with the conventional phase-contrast sequence (CINE-PC) and quantify the effect of free-breathing on CSF parameters at the intracranial and extracranial levels using a time-domain multiparametric analysis method. METHODS: Thirty-six healthy participants underwent MRI in a 3T scanner for CSF oscillations quantification at the cervical spine (C2-C3) and Sylvian aqueduct, using CINE-PC and RT-PC. CINE-PC uses 32 velocity maps to represent dynamic CSF flow over an average cardiac cycle, while RT-PC continuously quantifies CSF flow over 45-seconds. Free-breathing signals were recorded from 25 participants. RT-PC signal was segmented into independent cardiac cycle flow curves (Qt) and reconstructed into an averaged Qt. To assess RT-PC's accuracy, parameters such as segmented area, flow amplitude, and stroke volume (SV) of the reconstructed Qt from RT-PC were compared with those derived from the averaged Qt generated by CINE-PC. The breathing signal was used to categorize the Qt into expiratory or inspiratory phases, enabling the reconstruction of two Qt for inspiration and expiration. The breathing effects on various CSF parameters can be quantified by comparing these two reconstructed Qt. RESULTS: RT-PC overestimated CSF area (82.7% at aqueduct, 11.5% at C2-C3) compared to CINE-PC. Stroke volumes for CINE-PC were 615 mm³ (aqueduct) and 43 mm³ (spinal), and 581 mm³ (aqueduct) and 46 mm³ (spinal) for RT-PC. During thoracic pressure increase, spinal CSF net flow, flow amplitude, SV, and cardiac period increased by 6.3%, 6.8%, 14%, and 6%, respectively. Breathing effects on net flow showed a significant phase difference compared to the other parameters. Aqueduct-CSF flows were more affected by breathing than spinal-CSF. CONCLUSIONS: RT-PC accurately quantifies CSF oscillations in real-time and eliminates the need for cardiac synchronization, enabling the quantification of the cardiac and breathing components of CSF flow. This study quantifies the impact of free-breathing on CSF parameters, offering valuable physiological references for understanding the effects of breathing on CSF dynamics.

The prepontine block and its relevance for the development and treatment of hydrocephalus.

OBJECTIVE: Pulsatile CSF flow patterns include flow through the ventricles to the subarachnoid space and cisterns and from the infra- to the supratentorial subarachnoid space. In this study, we demonstrate how an obstruction at the level of the prepontine space may lead to obstructive hydrocephalus with specific radiological characteristics, as well as the implications for treatment options. METHODS: We retrospectively collected data of patients who underwent surgery between February 2010 and December 2022 for hydrocephalus secondary to a suspected prepontine block. One additional patient diagnosed with prepontine block who did not undergo surgery was also included. We excluded patients with a background of previous unrelated neurosurgical procedures or CNS infections. RESULTS: Six children and two adults were included. Three presented with hydrocephalus on imaging, without any other underlying pathology. Five had a suprasellar arachnoid cyst, with its lower border abating the pons and occluding the spinal subarachnoid space (SAS). All cases had an open aqueduct on T2 sagittal sequences, as well as an infracerebellar or retrocerebellar CSF collection. In most cases, a horizontal web was identified in the prepontine region. Seven cases were treated with an endoscopic fenestration. One patient subsequently underwent a shunt surgery. All the operated children reached normal developmental milestones after surgery. CONCLUSIONS: This paper describes a rather small series of cases where clear obstruction was observed at the level of the prepontine subarachnoid space. We believe this anatomical subtlety adds to a better understanding of CSF pathways and the role of ETV in treating hydrocephalus, focusing on a small subgroup of patients without a clear obstruction.

Rapid brain MRI for image-guided ventricular catheter placement in pediatric patients: protocol and preliminary clinical outcomes.

OBJECTIVE: Neuronavigation is a useful adjunct for catheter placement during neurosurgical procedures for hydrocephalus or ventricular access. MRI protocols for navigation are lengthy and require sedation for young children. CT involves ionizing radiation. In this study, the authors introduce the clinical application of a 1-minute rapid MRI sequence that does not require sedation in young children and report their preliminary clinical experience using this technique in their pediatric population. METHODS: All patients who underwent ventricular catheter placement at a children's hospital using a rapid noncontrast MRI protocol, standard MRI, or head CT from July 2021 to August 2023 were included. Type of procedure, etiology of hydrocephalus, ventricle configuration and size, morphology of ventricles, need for adjunctive intraoperative ultrasound, duration of procedure, accuracy of catheter placement, and need for proximal revision within 90 days were retrospectively recorded and compared across imaging modalities. RESULTS: Sixty-eight patients underwent 83 procedures: 21 underwent CT navigation, 29 standard MRI, and 33 rapid MRI. Patients who received standard MRI more often had tumor etiology, while those who underwent CT and rapid MRI had posthemorrhagic etiology (χ2 = 13.04, p = 0.042). Intraoperative ultrasound was required for 1 patient in the standard MRI group and 1 patient in the CT group. There was no difference in procedure time across groups (p = 0.831). On multivariable analysis, procedure time differed by procedure type, where external ventricular drain placement and proximal revision were faster (p < 0.001 and p < 0.028, respectively). Proximal revision due to obstruction within 90 days occurred in 3 cases (in the same patient with complex loculated hydrocephalus) in the rapid MRI group and 2 cases in the CT group. CONCLUSIONS: Although this study was not powered for statistical inference, the authors report on the clinical use of a 1-minute rapid MRI sequence for neuronavigation in hydrocephalus or ventricular access surgery. There were no instances in which intraoperative ultrasound was required as an adjunct for procedures navigated with rapid MRI, and intraoperative time did not differ from that of standard navigation protocols.

Septostomy and Monroplasty in Isolated Lateral Ventricle After Removal of a Third Ventricle Colloid Cyst: 2-Dimensional Operative Video.

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.

CSF and venous blood flow from childhood to adulthood studied by real-time phase-contrast MRI.

PURPOSE: In vivo measurements of CSF and venous flow using real-time phase-contrast (RT-PC) MRI facilitate new insights into the dynamics and physiology of both fluid systems. In clinical practice, however, use of RT-PC MRI is still limited. Because many forms of hydrocephalus manifest in infancy and childhood, it is a prerequisite to investigate normal flow parameters during this period to assess pathologies of CSF circulation. This study aims to establish reference values of CSF and venous flow in healthy subjects using RT-PC MRI and to determine their age dependency. METHODS: RT-PC MRI was performed in 44 healthy volunteers (20 females, age 5-40 years). CSF flow was quantified at the aqueduct (Aqd), cervical (C3) and lumbar (L3) spinal levels. Venous flow measurements comprised epidural veins, internal jugular veins and inferior vena cava. Parameters analyzed were peak velocity, net flow, pulsatility, and area of region of interest (ROI). STATISTICAL TESTS: linear regression, student's t-test and analysis of variance (ANOVA). RESULTS: In adults volunteers, no significant changes in flow parameters were observed. In contrast, pediatric subjects exhibited a significant age-dependent decrease of CSF net flow and pulsatility in Aqd, C3 and L3. Several venous flow parameters decreased significantly over age at C3 and changed more variably at L3. CONCLUSION: Flow parameters varies depending on anatomical location and age. We established changes of brain and spinal fluid dynamics over an age range from 5-40 years. The application of RT-PC MRI in clinical care may improve our understanding of CSF flow pathology in individual patients.

IMAGINER: improving accuracy with a mixed reality navigation system during placement of external ventricular drains. A feasibility study.

OBJECTIVE: The placement of a ventricular catheter, that is, an external ventricular drain (EVD), is a common and essential neurosurgical procedure. In addition, it is one of the first procedures performed by inexperienced neurosurgeons. With or without surgical experience, the placement of an EVD according to anatomical landmarks only can be difficult, with the potential risk for inaccurate catheter placement. Repeated corrections can lead to avoidable complications. The use of mixed reality could be a helpful guide and improve the accuracy of drain placement, especially in patients with acute pathology leading to the displacement of anatomical structures. Using a human cadaveric model in this feasibility study, the authors aimed to evaluate the accuracy of EVD placement by comparing two techniques: mixed reality and freehand placement. METHODS: Twenty medical students performed the EVD placement procedure with a Cushing's ventricular cannula on the right and left sides of the ventricular system. The cannula was placed according to landmarks on one side and with the assistance of mixed reality (Microsoft HoloLens 2) on the other side. With mixed reality, a planned trajectory was displayed in the field of view that guides the placement of the cannula. Subsequently, the actual position of the cannula was assessed with the help of a CT scan with a 1-mm slice thickness. The bony structure as well as the left and right cannula positions were registered to the CT scan with the planned target point before the placement procedure. CloudCompare software was applied for registration and evaluation of accuracy. RESULTS: EVD placement using mixed reality was easily performed by all medical students. The predefined target point (inside the lateral ventricle) was reached with both techniques. However, the scattering radius of the target point reached through the use of mixed reality (12 mm) was reduced by more than 54% compared with the puncture without mixed reality (26 mm), which represents a doubling of the puncture accuracy. CONCLUSIONS: This feasibility study specifically showed that the integration and use of mixed reality helps to achieve more than double the accuracy in the placement of ventricular catheters. Because of the easy availability of these new tools and their intuitive handling, we see great potential for mixed reality to improve accuracy.

Accuracy of routine external ventricular drain placement following a mixed reality-guided twist-drill craniostomy.

OBJECTIVE: The traditional freehand placement of an external ventricular drain (EVD) relies on empirical craniometric landmarks to guide the craniostomy and subsequent passage of the EVD catheter. The diameter and trajectory of the craniostomy physically limit the possible trajectories that can be achieved during the passage of the catheter. In this study, the authors implemented a mixed reality-guided craniostomy procedure to evaluate the benefit of an optimally drilled craniostomy to the accurate placement of the catheter. METHODS: Optical marker-based tracking using an OptiTrack system was used to register the brain ventricular hologram and drilling guidance for craniostomy using a HoloLens 2 mixed reality headset. A patient-specific 3D-printed skull phantom embedded with intracranial camera sensors was developed to automatically calculate the EVD accuracy for evaluation. User trials consisted of one blind and one mixed reality-assisted craniostomy followed by a routine, unguided EVD catheter placement for each of two different drill bit sizes. RESULTS: A total of 49 participants were included in the study (mean age 23.4 years, 59.2% female). The mean distance from the catheter target improved from 18.6 ± 12.5 mm to 12.7 ± 11.3 mm (p = 0.0008) using mixed reality guidance for trials with a large drill bit and from 19.3 ± 12.7 mm to 10.1 ± 8.4 mm with a small drill bit (p < 0.0001). Accuracy using mixed reality was improved using a smaller diameter drill bit compared with a larger bit (p = 0.039). Overall, the majority of the participants were positive about the helpfulness of mixed reality guidance and the overall mixed reality experience. CONCLUSIONS: Appropriate indications and use cases for the application of mixed reality guidance to neurosurgical procedures remain an area of active inquiry. While prior studies have demonstrated the benefit of mixed reality-guided catheter placement using predrilled craniostomies, the authors demonstrate that real-time quantitative and visual feedback of a mixed reality-guided craniostomy procedure can independently improve procedural accuracy and represents an important tool for trainee education and eventual clinical implementation.

ChOP-CT: quantitative morphometrical analysis of the Hindbrain Choroid Plexus by X-ray micro-computed tomography.

The Hindbrain Choroid Plexus is a complex, cerebrospinal fluid-secreting tissue that projects into the 4th vertebrate brain ventricle. Despite its irreplaceability in the development and homeostasis of the entire central nervous system, the research of Hindbrain Choroid Plexus and other Choroid Plexuses has been neglected by neuroscientists for decades. One of the obstacles is the lack of tools that describe the complex shape of the Hindbrain Choroid Plexus in the context of brain ventricles. Here we introduce an effective tool, termed ChOP-CT, for the noninvasive, X-ray micro-computed tomography-based, three-dimensional visualization and subsequent quantitative spatial morphological analysis of developing mouse Hindbrain Choroid Plexus. ChOP-CT can reliably quantify Hindbrain Choroid Plexus volume, surface area, length, outgrowth angle, the proportion of the ventricular space occupied, asymmetries and general shape alterations in mouse embryos from embryonic day 13.5 onwards. We provide evidence that ChOP-CT is suitable for the unbiased evaluation and detection of the Hindbrain Choroid Plexus alterations within various mutant embryos. We believe, that thanks to its versatility, quantitative nature and the possibility of automation, ChOP-CT will facilitate the analysis of the Hindbrain Choroid Plexus in the mouse models. This will ultimately accelerate the screening of the candidate genes and mechanisms involved in the onset of various Hindbrain Choroid Plexus-related diseases.

White matter paramagnetic rim and non-rim lesions share a periventricular gradient in multiple sclerosis: A 7-T imaging study.

BACKGROUND: Paramagnetic rim white matter (WM) lesions (PRL) are thought to be a main driver of non-relapsing multiple sclerosis (MS) progression. It is unknown whether cerebrospinal fluid (CSF)-soluble factors diffusing from the ventricles contribute to PRL formation. OBJECTIVE: To investigate the distribution of PRL and non-rim brain WM lesions as a function of distance from ventricular CSF, their relationship with cortical lesions, the contribution of lesion phenotype, and localization to neurological disability. METHODS: Lesion count and volume of PRL, non-rim WM, leukocortical lesion (LCL), and subpial/intracortical lesions were obtained at 7-T. The brain WM was divided into 1-mm-thick concentric rings radiating from the ventricles to extract PRL and non-rim WM lesion volume from each ring. RESULTS: In total, 61 MS patients with ⩾1 PRL were included in the study. Both PRL and non-rim WM lesion volumes were the highest in the periventricular WM and declined with increasing distance from ventricles. A CSF distance-independent association was found between non-rim WM lesions, PRL, and LCL, but not subpial/intracortical lesions. Periventricular non-rim WM lesion volume was the strongest predictor of neurological disability. CONCLUSIONS: Non-rim and PRL share a gradient of distribution from the ventricles toward the cortex, suggesting that CSF proximity equally impacts the prevalence of both lesion phenotypes.

Disruption of Cerebellar Granular Layer as a Consequence of Germinal Matrix Intraventricular Hemorrhage in Extreme Prematurity: An Acute Direct Mechanism Too?

Cerebellum is an important brain structure for the future development of motor, cognitive, and behavioral abilities in children. This structure undergoes its most significant growth during the third trimester of pregnancy. Prematurity gathers several risk factors for cerebellar impairment and underdevelopment, and among them is ventricular dilatation following germinal matrix intraventricular hemorrhage (GMH-IVH). In this report, we illustrate how this prevalent complication associated with prematurity may induce secondary cerebellar cortical damage. A premature male born by an emergency Caesarean section displayed massive GMH-IVH at brain ultrasound performed after three hours of extrauterine life and died after 18 hours of life, despite maximized vital support. We report a postmortem histopathological specimen of the cerebellar cortex showing the disruption of the external granular layer (EGL) by hemorrhagic content flowing from the supratentorial ventricles into the fourth ventricle and cisterna magna. The expansion of the ventricular system and the presence of blood in the lateral ventricles can cause inflammation and damage to the cerebellar gyri. Experimental models have shown a thinning of the EGL, suggesting that blood surrounding the cerebellum has a harmful action. Additionally, a sudden influx of cerebrospinal fluid from the lateral ventricles may directly contribute to cerebellar damage, indicating that this may be another way in which the cerebellar gyri are impaired during acute severe GMH-IVH. This is the first histopathologically confirmed case of acute disruption in the cerebellar cortex during a GMH-IVH in a premature baby.

Genetic architectures of cerebral ventricles and their overlap with neuropsychiatric traits.

The cerebral ventricles are recognized as windows into brain development and disease, yet their genetic architectures, underlying neural mechanisms and utility in maintaining brain health remain elusive. Here we aggregated genetic and neuroimaging data from 61,974 participants (age range, 9 to 98 years) in five cohorts to elucidate the genetic basis of ventricular morphology and examined their overlap with neuropsychiatric traits. Genome-wide association analysis in a discovery sample of 31,880 individuals identified 62 unique loci and 785 candidate genes associated with ventricular morphology. We replicated over 80% of loci in a well-matched cohort of lateral ventricular volume. Gene set analysis revealed enrichment of ventricular-trait-associated genes in biological processes and disease pathogenesis during both early brain development and degeneration. We explored the age-dependent genetic associations in cohorts of different age groups to investigate the possible roles of ventricular-trait-associated loci in neurodevelopmental and neurodegenerative processes. We describe the genetic overlap between ventricular and neuropsychiatric traits through comprehensive integrative approaches under correlative and causal assumptions. We propose the volume of the inferior lateral ventricles as a heritable endophenotype to predict the risk of Alzheimer's disease, which might be a consequence of prodromal Alzheimer's disease. Our study provides an advance in understanding the genetics of the cerebral ventricles and demonstrates the potential utility of ventricular measurements in tracking brain disorders and maintaining brain health across the lifespan.

Continuous Intrathecal Medication Delivery With the IRRA flow Catheter: Pearls and Early Experience.

BACKGROUND AND OBJECTIVES: Intrathecal (IT) medications are routinely introduced through catheterization of the intraventricular space or subarachnoid space. There has been sporadic use of IT medications delivered directly to the ventricle either by intermittent injection through an external ventricular drain (EVD) or by an Ommaya reservoir with a ventricular catheter. IT medication delivery through EVD has many drawbacks, including the necessary opening of a sterile system, delivery of medication in a bolus form, and requirements to clamp the EVD after medication delivery. Despite these setbacks, IT medications delivered through EVD have been used across a wide range of applications, including antibiotic delivery treatment of vasospasm with nicardipine and delivery of tissue plasminogen activator. METHODS: We used a newly developed active fluid exchange device to treat various severe conditions involved in the cerebral ventricles. Here, we present our treatment protocols and advice on the techniques related to successful active fluid exchange therapy. RESULTS: Seventy patients have been treated with our system with various conditions, including subarachnoid hemorrhage, intraventricular hemorrhage, ventriculitis, and cerebral abscess. Total complication rate was 14% with only 1 catheter occlusion and low rates of hemorrhage, infection, and spinal fluid leak. CONCLUSION: Current continuous IT medication dosages and protocols are based on reports and consensus statements evaluating intermittent instillation of medication boluses. The pharmacokinetics of continuous dosing and the therapeutic and safety profiles of the medications need to be studied in a prospective manner to evaluate the true optimal dosing standards. Furthermore, the ability to deliver continuous, sterile medications directly through an IT route will open new avenues of pharmacotherapy that were previously closed. This report serves as a basic guide for the safe and effective use of the IRRA flow active fluid exchange catheter to deliver IT medications.

Evaluation of a Fully Automated Method for Ventricular Volume Segmentation Before and After Shunt Surgery in Idiopathic Normal Pressure Hydrocephalus.

BACKGROUND: Determination of the ventricle size in idiopathic normal pressure hydrocephalus (iNPH) is essential for diagnosis and follow-up of shunt results. Fully automated segmentation methods are anticipated to optimize the accuracy and time efficiency of ventricular volume measurements. We evaluated the accuracy of preoperative and postoperative ventricular volume measurements in iNPH by a magnetic resonance imaging (MRI)-based licensed software for fully automated quantitative assessment. METHODS: Forty-eight patients diagnosed with iNPH were retrospectively analyzed. All patients received a ventriculoperitoneal shunt and had symptom grading and routine MRI preoperatively and 3-6 months postoperatively. Ventricular volumes, generated by fully automated T1-weighted imaging volume sequence segmentation, were compared with semiautomatic measurements and routine radiologic reports. The relation of postoperative ventricular size change to clinical response was evaluated. RESULTS: Fully automated segmentation was achieved in 95% of the MRIs, but showed various rates of 8 minor segmentation errors. The correlation between both segmentation methods was very strong (r >0.9) and the agreement very good using Bland-Altman analyses. The ventricular volumes differed significantly between semiautomated and fully automated segmentations and between preoperative and postoperative MRI. The fully automated method systematically overestimated the ventricles by a median 15 mL preoperatively and 14 mL postoperatively; hence, the magnitudes of volume changes were equivalent. Routine radiologic reports of ventricular size changes were inaccurate in 51% and lacked association with treatment response. Objectively measured ventricular volume changes correlated moderately with postoperative clinical improvement. CONCLUSIONS: A fully automated volumetric method permits reliable evaluation of preoperative ventriculomegaly and postoperative ventricular volume change in idiopathic normal pressure hydrocephalus.

The Technique for Transorbital Ventricular Puncture: An Anatomic Approach.

BACKGROUND AND OBJECTIVES: Transorbital ventricular puncture is a minimally invasive described procedure with poor landmarks and anatomic references. This approach can be easily performed to save patients with intracranial hypertension, especially when it is secondary to an acute decompensated hydrocephalus. This study aims to describe anatomic structures and landmarks to facilitate the execution of transorbital puncture in emergency cases. METHODS: We analyzed 120 head computed tomographies to show the best area to perform the procedure in the orbital roof. Two adult cadavers (4 sides) were punctured in the predetermined area. Angles, distances, landmarks, and anatomic structures were registered. This approach to the ventricular system may be performed at bedside to relieve intracranial hypertension only in specific cases. RESULTS: The perforation point is 2.5 cm (female) or 3.0 cm (male) lateral to the midline and immediately inferior to the superciliary arch. A vertical line, parallel to midline, was drawn on the outer edge of the patient's forehead, the needle was 45° inferiorly and 20° medially and then progressed 2.0 cm backwards to reach the bone perforation point. After that, it was advanced another 4.5cm approximately until it reached the anterior horn of the lateral ventricle. CONCLUSION: Based on statistical and experimental evidences, we were able to establish reliable anatomic reference points to access the anterior horn of the lateral ventricle through transorbital puncture.