Aging-related volume changes in the brain and cerebrospinal fluid using artificial intelligence-automated segmentation

OBJECTIVES

To verify the reliability of the volumes automatically segmented using a new artificial intelligence (AI)-based application and evaluate changes in the brain and CSF volume with healthy aging.

METHODS

The intracranial spaces were automatically segmented in the 21 brain subregions and 5 CSF subregions using the AI-based application on the 3D T1-weighted images in healthy volunteers aged > 20 years. Additionally, the automatically segmented volumes of the total ventricles and subarachnoid spaces were compared with the manually segmented volumes of those extracted from 3D T2-weighted images using the intra-class correlation and Bland-Altman analysis.

RESULTS

In this study, 133 healthy volunteers aged 21-92 years were included. The mean intra-class correlations between the automatically and manually segmented volumes of the total ventricles and subarachnoid spaces were 0.986 and 0.882, respectively. The increase in the CSF volume was estimated to be approximately 30 mL (2%) per decade from 265 mL (18.7%) in the 20s to 488 mL (33.7%) in ages above 80 years; however, the increase in the volume of total ventricles was approximately 20 mL (< 2%) until the 60s and increased in ages above 60 years.

CONCLUSIONS

This study confirmed the reliability of the CSF volumes using the AI-based auto-segmentation application. The intracranial CSF volume increased linearly because of the brain volume reduction with aging; however, the ventricular volume did not change until the age of 60 years and above and then gradually increased. This finding could help elucidate the pathogenesis of chronic hydrocephalus in adults.

KEY POINTS

• The brain and CSF spaces were automatically segmented using an artificial intelligence-based application. • The total subarachnoid spaces increased linearly with aging, whereas the total ventricle volume was around 20 mL (< 2%) until the 60s and increased in ages above 60 years. • The cortical gray matter gradually decreases with aging, whereas the subcortical gray matter maintains its volume, and the cerebral white matter increases slightly until the 40s and begins to decrease from the 50s.

Endoscopic Third Ventriculostomy - A Review

BACKGROUND

Endoscopic third ventriculostomy (ETV) has become a proven modality for treating obstructive and selected cases of communicating hydrocephalus.

OBJECTIVE

This review aims to summarize the indications, preoperative workup, surgical technique, results, postoperative care, complications, advantages, and limitations of an ETV.

MATERIALS AND METHODS

A thorough review of PubMed and Google Scholar was performed. This review is based on the relevant articles and authors' experience.

RESULTS

ETV is indicated in obstructive hydrocephalus and selected cases of communicating hydrocephalus. Studying preoperative imaging is critical, and a detailed assessment of interthalamic adhesions, the thickness of floor, arteries or membranes below the third ventricle floor, and prepontine cistern width is essential. Blunt perforation in a thin floor, while bipolar cautery at low settings and water jet dissection are preferred in a thick floor. The appearance of stoma pulsations and intraoperative ventriculostomography reassure stoma and basal cistern patency. The intraoperative decision for shunt, external ventricular drainage, or Ommaya reservoir can be taken. Magnetic resonance ventriculography and cine phase-contrast magnetic resonance imaging can determine stoma patency. Good postoperative care with repeated cerebrospinal fluid drainage enhances outcomes in selected cases. Though the complications mostly occur in an early postoperative phase, delayed lethal ones may happen. Watching live surgeries, assisting expert surgeons, and practicing on cadavers and models can shorten the learning curve.

CONCLUSION

ETV is an excellent technique for managing obstructive and selected cases of communicating hydrocephalus. Good case selection, methodical technique, and proper training under experts are vital.

Ganglioglioma Arising from the Septum Pellucidum: Case Report and Review of the Literature

BACKGROUND

Gangliogliomas are low-grade neoplasms that typically affect patients under the age of 30 and present with epilepsy and symptoms of mass effect. Here, we report a case of an intraventricular ganglioglioma involving the septum pellucidum in a pediatric patient with history of optic glioma. Only one other pediatric intraventricular ganglioglioma arising from the septum pellucidum has been reported previously.

CASE REPORT

The patient initially presented at 9 months of age with a pilocytic astrocytoma centered on the optic chiasm, treated with chemotherapy and radiation at 3 years of age. Routine follow-up imaging at 13 years of age revealed the development of a mass in the septum pellucidum, which was subtotally resected endoscopically because of its proximity to the fornices. Pathology confirmed a ganglioglioma positive for the BRAF V600E mutation. The tumor residual progressed and was treated with stereotactic radiosurgery. The patient was asymptomatic at her 6-month follow-up visit and the size of the nodule remained stable.

LITERATURE REVIEW

Our review of the 25 previously reported intraventricular gangliogliomas found that their pre-surgical diagnoses were often incorrect, reflecting the difficulty of making the diagnosis with signs, symptoms, and imaging alone. Patients can be reassured that the prognosis is generally favorable following uncomplicated neurosurgical resection.

Relationships between Head Circumference Percentile, Lumbar Puncture Pressure, and Cerebrospinal Fluid Space in Young Children: Increased Cerebrospinal Space and Pressure May Result in Compensatory Enlargement of Head Circumference Only in the Infant Period

BACKGROUND

The aim of this study was to retrospectively evaluate and analyze the relationships between head circumference percentile (HCP), lumbar puncture pressure (LPP), and cerebrospinal fluid (CSF) space.

METHODS

The 88 patients were divided into 3 age groups (group 1, up to 12 months; group 2, 12-36 months; group 3, 36-72 months).

RESULTS

In group 1 (n = 40), there was a significant positive correlation of the HCP with the LPP (r =0.414, p =0.008), Evans ratio (r =0.365, p =0.021), and thickness of subdural hygroma (SDHG; r =0.403, p =0.010). Group 2 (n = 29) revealed a significant positive correlation between the LPP and the thickness of SDHG (r =0.459, p =0.012). Group 3 (n = 19) showed no significant correlation among these factors. Overall, age was related with SDHG thickness both in infants and toddlers, while HCP was related with LPP, Evans ratio, and SDHG thickness only in infants, and LPP was related with SDHG thickness only in toddlers.

CONCLUSION

We suggest that increased cerebrospinal space and pressure may result in compensatory enlargement of head circumference only in the infant period, and the SDHG thickness decreases with age during the infant and toddler phases.

Next generation of ventricular catheters for hydrocephalus based on parametric designs

BACKGROUND

The flow pattern of the cerebrospinal fluid is probably the most important factor related to obstruction of ventricular catheters during the normal treatment of hydrocephalus. To better comprehend the flow pattern, we have carried out a parametric study via numerical models of ventricular catheters. In previous studies, the flow was studied under steady and, recently, in pulsatile boundary conditions by means of computational fluid dynamics (CFD) in three-dimensional catheter models.

OBJECTIVE

This study aimed to bring in prototype models of catheter CFD flow solutions as well to introduce the theory behind parametric development of ventricular catheters.

METHODS

A preceding study allowed deriving basic principles which lead to designs with improved flow patterns of ventricular catheters. The parameters chosen were the number of drainage segments, the distances between them, the number and diameter of the holes on each segment, as well as their relative angular position.

RESULTS

CFD results of previously unreleased models of ventricular catheter flow solutions are presented in this study. Parametric development guided new designs with better flow distribution while lowering the shear stress of the catheters holes. High-resolution 3D printed catheter solutions of three models and basic benchmark testing are introduced as well.

CONCLUSIONS

The next generation of catheter with homogeneous flow patterns based on parametric designs may represent a step forward for the treatment of hydrocephalus, by possibly broadening their lifespan.

CSF flow pathways through the ventricle-cistern interfaces in kaolin-induced hydrocephalus rats-laboratory investigation

PURPOSE

The goal of this study was to identify direct cerebrospinal fluid (CSF) pathways in the interface between ventricles and cisterns. Such routes are hypothesized to be involved in alternative CSF flows in abnormal circumstances of CSF circulation.

METHODS

Chronic obstructive hydrocephalus models were induced in ten Sprague-Dawley rats with kaolin injection into the cisterna magna. Three weeks after the kaolin injection, when thick arachnoid fibrosis obliterated the fourth ventricular outlets, cationized ferritin was stereotactically infused as a tracer into the lateral ventricle in order to observe the pathways from the ventricles to the subarachnoid space. Animals were killed in 48 h and brains were sectioned. CSF flow pathways were traced by the staining of ferritin with ferrocyanide.

RESULTS

Eight out of ten rats developed hydrocephalus. The subarachnoid membranes of the convexity and basal cisterns were severely adhered such that most of the ferritin remained in the ventricles whereas basal and convexity cisterns were clear of ferritin. In six out of the eight hydrocephalus rats, ferritin leaked from the third ventricle into the quadrigeminal cistern, and from the lateral ventricle into the ambient cistern.

CONCLUSIONS

The interfaces between the third ventricle and the quadrigeminal cistern, and between the lateral ventricle and the ambient cistern appear to be alternative CSF pathways in a pathologic condition such as obstructive hydrocephalus.

Case report of the extramedullary hematopoiesis presented as a hypervascular intracranial mass

Thalassemia is a hematologic disorder that causes ineffective hematopoiesis and is related to severe anemia, iron overload, extramedullary hematopoiesis, and hepatomegaly. Hepatomegaly is related to significant extramedullary hematopoiesis. The other sites that are involved in extramedullary hematopoiesis are spleen, lymph nodes, paraspinal regions, kidney, pleura, and intestine, but intracranial involvement is a rare presentation. We discuss about a case with intracranial medullary hematopoiesis in a thalassemic patient.