Possibilities of Using Multi-b-value Diffusion Magnetic Resonance Imaging for Classification of Brain Lesions

In contrast to conventional diffusion magnetic resonance imaging (MRI), multi-b-value diffusion MRI methods are able to separate the signal from free water, pseudo-diffusion, and non-Gaussian components of water molecule diffusion. These approaches can then be utilised in so-called intravoxel incoherent motion imaging and diffusion kurtosis imaging. Various parameters provided by these methods can describe additional characteristics of the tissue microstructure and potentially help in the diagnosis and classification of various pathological processes. In this review, we present the basic principles and methods of analysing multi-b-value diffusion imaging data and specifically focus on the known possibilities for its use in the diagnosis of brain lesions. We also suggest possible directions for further research.

Epidural Hematoma, a Rare Complication After the Use of Mayfield Clamp: A Case Report and Review of the Literature

Herein, we describe a case of epidural hematoma associated with the use of a Mayfield head clamp. An 18-year old patient with an upper brainstem tumour causing obstructive hydrocephalus underwent a routine third ventriculostomy, which unexpectedly revealed an intracranial hemorrhage. We outline potential risk factors, propose an algorithm for preventing complications associated with the use of pin-type fixation, and conducted a structured review of the literature to identify similar clinical scenarios.

Federated learning enables big data for rare cancer boundary detection

Although machine learning (ML) has shown promise across disciplines, out-of-sample generalizability is concerning. This is currently addressed by sharing multi-site data, but such centralization is challenging/infeasible to scale due to various limitations. Federated ML (FL) provides an alternative paradigm for accurate and generalizable ML, by only sharing numerical model updates. Here we present the largest FL study to-date, involving data from 71 sites across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, reporting the largest such dataset in the literature (n = 6, 314). We demonstrate a 33% delineation improvement for the surgically targetable tumor, and 23% for the complete tumor extent, over a publicly trained model. We anticipate our study to: 1) enable more healthcare studies informed by large diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further analyses for glioblastoma by releasing our consensus model, and 3) demonstrate the FL effectiveness at such scale and task-complexity as a paradigm shift for multi-site collaborations, alleviating the need for data-sharing.

Early Dynamics of Interleukin-6 in Cerebrospinal Fluid after Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

 Subarachnoid hemorrhage (SAH) is a severe condition associated with high mortality. Early brain injury (EBI) plays an important role in the pathophysiology of SAH, and inflammation is a major contributor to EBI. Inflammation is a widely studied topic in both experimental and clinical conditions; however, just a few clinical studies have focused primarily on the early inflammatory response after SAH, and detailed information about the association between the dynamics of early inflammatory response with main clinical characteristics is lacking. This study analyzes the early dynamics of inflammatory response after SAH and evaluates the possible associations between the markers of early inflammatory response and main clinical characteristics.

PATIENTS AND METHODS

 A total of 47 patients with a diagnosis of aneurysmal SAH within the last 24 hours were enrolled in the study. All treatments, including treatment of aneurysm (surgery/coiling) and implantation of a drainage system (external ventricular drainage/lumbar catheter), were conducted in the same way as in other patients with this diagnosis. Blood and cerebrospinal fluid (CSF) samples were collected three times a day for 4 days. The dynamics of proinflammatory cytokines were assessed, and associations between levels of the proinflammatory cytokines interleukin (IL)-6, IL-1β, or tumor necrosis factor (TNF)α and main clinical characteristics were evaluated using linear mixed-effect models.

RESULTS

 The CSF levels of IL-6 were massively increased initially after SAH (up to 72 hours) with an additional increase in later phases (after 72 hours), but there was high variability in IL-6 levels. A significant association was noted between the Glasgow Outcome Scale score and both overall levels of IL-6 (p = 0.0095) and their dynamics (p = 0.0208); the effect of the Hunt and Hess scale was borderline (p = 0.0887). No association was found between IL-6 levels and Fisher grade, modality of treatment (surgery, coiling, no treatment), and later development of cerebral vasospasm. Plasmatic levels of IL-6 increased slightly, but no significant association was found. The levels of IL-1β and TNFα were within the physiologic range in both CSF and plasma.

CONCLUSIONS

 Early dynamics of IL-6 in CSF are associated with a patient́s outcome. But it is difficult to use IL-6 alone for outcome prediction due to its high variability. The question is whether the dynamics of IL-6 could be used in combination with other early markers associated with brain injury. More detailed research is required to answer this question.

[Pregnancy and delivery in patients with an implanted shunt for hydrocephalus]

Hydrocephalus is a disorder of abnormal accumulation of cerebrospinal fluid in the intracranial space, usually in the cerebral ventricles. The number of patients reaching reproductive age and intending to become pregnant has increased in recent years because of treatment advances. An implanted shunt is usually introduced into the abdominal cavity (ventriculoperitoneal shunt). Numerous changes occur during pregnancy, mainly increased accumulation of water, increased intracranial cerebrospinal fluid volume and increased intra-abdominal pressure as a result of the growing uterus. These changes contribute to increased incidence of complications during pregnancy and childbirth. Therefore, it is necessary to make a preconception exam and specify pregnancy management, a suitable method of childbirth and dealing with potential complications. Multidisciplinary care is mandatory with the dominant cooperation of obstetricians and neurosurgeons who should be also available during the delivery when needed. Possible shunt malfunction is necessary to diagnose properly and in time and solve it individually, taking into account the overall and neurological status of the patient and gestational age. The presence of a shunt does not affect pregnancy and vaginal delivery is considered by most authors as the first option. Primary cesarean section is preffered in patients with obstructive hydrocephalus or rapid deterioration in the case of shunt malfunction. Epidural anesthesia or general, eventually spinal anesthesia are recommended.

KEYWORDS

hydrocephalus, shunt, ventriculoperitoneal shunt, ventriculoatrial shunt, endoscopy, endoscopic third ventriculostomy, pregnancy.

[The use of telemetric intracranial pressure monitoring in the differential diagnosis of idiopathic intracranial hypertension - a case report]

Idiopathic intracranial hypertension is a disorder that results from an increase of intracranial pressure with unknown cause. A single measurement of intracranial pressure only provides data at one given point in time. Therefore, telemetric monitoring of intracranial pressure was performed in a patient with fluctuating headache and significantly impaired vision, which together accounted for 226.2 hours of recording during normal daily activities. Elevated intracranial pressure was not found during monitoring, so we did not indicate the patient for shunt surgery.

[Comparison of laparotomic and laparoscopic techniques for implantation of the peritoneal part of the shunt in the treatment of hydrocephalus]

INTRODUCTION

Implantation of a ventriculoperitoneal shunt is a standard procedure in the treatment of hydrocephalus. Shunt malfunction can be due to various causes, such as failure of the peritoneal (distal) part of the shunt with a frequency of 5% to 47%.

OBJECTIVE

The aim of this study was to compare laparoscopic and laparotomic techniques for implantation of a ventriculoperitoneal shunt.

MATERIAL AND METHODS

We considered a cohort of 304 patients with hydrocephalus, acquired during a 10-year period, who underwent surgical intervention at the Neurosurgical and Surgical Clinics of the University Hospital Brno.

RESULTS

The 304 patients underwent a total of 392 operations, of which 67 (17.1%) were performed using a laparoscopic approach and 325 (82.9%) using a laparotomic approach. In the laparotomy group, 59 (18.2%) interventions were repeated due to complications of the peritoneal part of the shunt, while in the laparoscopy group revisions accounted for only 3 cases (4.5%).

CONCLUSIONS

The laparoscopic technique significantly reduces the risk of complications of the peritoneal part of the shunt, and thus the overall complications associated with the implantation of the ventriculoperitoneal shunt. Laparoscopy is indicated in the case of migration of the peritoneal catheters into the abdominal cavity and is also very helpful in revisions in the case of malfunction of the peritoneal part of the shunt or in the case of previous abdominal surgery. It can explain the anatomical conditions in the abdominal cavity and it is able to treat any incidental pathology.

[Lesions in the popliteal fossa with neurologic symptomatology--case reports, diagnostics and treatment]

The lesions arising in the popliteal fossa are varied. We report two different lesions related to the peroneal nerve that presented with neurologic symptoms. Both were initially treated at surgical department with insufficient diagnostics and finally required a neurosurgical operation. We emphasize performing complete diagnostics that may avoid unnecessary burden for the patient and healthcare personnel. Patients with proven intimate relation of the lesion to nerve structures in the popliteal fossa should be referred to neurosurgical department.

[Orbito-zygomatic approach to suprasellar lesions]

The article deals with the orbitozygomatic approach used in the treatment of pathological processes located in the anterior, medial and superior third of the posterior cranial fossa with special attention paid to suprasellar lesions. It presents a step-by-step guide to the surgical procedure, including potential complications. Furthermore, various modifications of the orbitozygomatic approach are discussed and several references from other authors are quoted with respect to the comparison of different approaches based on quantification criteria. The orbitozygomatic approach is the method of choice in the treatment of suprasellar lesions, in particular in the case of voluminous expansion. It allows for more radical resection, because the operational field is more extensive and operation in deep intracranial structures is easier.