Intraventricular haemorrhage and posthaemorrhagic ventricular dilatation: moving beyond CSF diversion

Noninvasive optical monitoring of cerebral hemodynamics in a preclinical model of neonatal intraventricular hemorrhage

Intraventricular hemorrhage (IVH) is a common complication in premature infants and is associated with white matter injury and long-term neurodevelopmental disabilities. Standard diagnostic tools such as cranial ultrasound and MRI are widely used in both preclinical drug development and clinical practice to detect IVH. However, these methods are limited to endpoint assessments of blood accumulation and do not capture real-time changes in germinal matrix blood flow leading to IVH. This limitation could potentially result in missed opportunities to advance drug candidates that may have protective effects against IVH. In this pilot study, we aimed to develop a noninvasive optical approach using diffuse correlation spectroscopy (DCS) to monitor real-time hemodynamic changes associated with hemorrhagic events and pre-hemorrhagic blood flow in a preclinical rabbit model of IVH. DCS measurements were conducted during the experimental induction of IVH, and results were compared with ultrasound and histological analysis to validate findings. Significant changes in hemodynamics were detected in all animals subjected to IVH-inducing procedures, including those that did not show clear positive results on ultrasound 18 h later. The study revealed progressively elevated coefficients of variation in blood flow, largely driven by temporal fluctuations in the <0.25 Hz range. Our findings suggest that real-time optical monitoring with DCS can provide critical insights heralding pathological blood flow changes, offering a more sensitive and informative tool for evaluating potential therapeutics that may help avert the progression to IVH.

Pharmacological Strategies and Surgical Management of Posthemorrhagic Hydrocephalus Following Germinal Matrix-Intraventricular Hemorrhage in Preterm Infants

Germinal matrix-intraventricular hemorrhage (GM-IVH) is a detrimental neurological complication that occurs in preterm infants, especially in babies born before 32 weeks of gestation and in those with a very low birth weight. GM-IVH is defined as a rupture of the immature and fragile capillaries located in the subependymal germinal matrix zone of the preterm infant brain, and it can lead to detrimental neurological sequelae such as posthemorrhagic hydrocephalus (PHH), cerebral palsy, and other cognitive impairments. PHH following GM-IVH is difficult to treat in the clinic, and no levelone strategies have been recommended to pediatric neurosurgeons. Several cellular and molecular mechanisms of PHH following GM-IVH have been studied in animal models, but no effective pharmacological strategies have been used in the clinic. Thus, a comprehensive understanding of molecular mechanisms, potential pharmacological strategies, and surgical management of PHH is urgently needed. The present review presents a synopsis of the pathogenesis, diagnosis, and cellular and molecular mechanisms of PHH following GM-IVH and explores pharmacological strategies and surgical management.

Treatment Strategies and Challenges to Avoid Cerebrospinal Fluid Shunting for Pediatric Hydrocephalus

Treatment for pediatric hydrocephalus aims not only to shrink the enlarged ventricle morphologically but also to create an intracranial environment that provides the best neurocognitive development and to deal with various treatment-related problems over a long period of time. Although the primary diseases that cause hydrocephalus are diverse, the ventricular peritoneal shunt has been introduced as the standard treatment for several decades. Nevertheless, complications such as shunt infection and shunt malfunction are unavoidable; the prognosis of neurological function is severely affected by such factors, especially in newborns and infants.

In recent years, treatment concepts have been attempted to avoid shunting, mainly in the context of pediatric cases. In this review, the current role of neuroendoscopic third ventriculostomy for noncommunicating hydrocephalus is discussed and a new therapeutic concept for post intraventricular hemorrhagic hydrocephalus in preterm infants is documented. To avoid shunt placement and achieve good neurodevelopmental outcomes for pediatric hydrocephalus, treatment modalities must be developed.

Mechanisms of neuroinflammation in hydrocephalus after intraventricular hemorrhage: a review

Intraventricular hemorrhage (IVH) is a significant cause of morbidity and mortality in both neonatal and adult populations. IVH not only causes immediate damage to surrounding structures by way of mass effect and elevated intracranial pressure; the subsequent inflammation causes additional brain injury and edema. Of those neonates who experience severe IVH, 25-30% will go on to develop post-hemorrhagic hydrocephalus (PHH). PHH places neonates and adults at risk for white matter injury, seizures, and death. Unfortunately, the molecular determinants of PHH are not well understood. Within the past decade an emphasis has been placed on neuroinflammation in IVH and PHH. More information has come to light regarding inflammation-induced fibrosis and cerebrospinal fluid hypersecretion in response to IVH. The aim of this review is to discuss the role of neuroinflammation involving clot-derived neuroinflammatory factors including hemoglobin/iron, peroxiredoxin-2 and thrombin, as well as macrophages/microglia, cytokines and complement in the development of PHH. Understanding the mechanisms of neuroinflammation after IVH may highlight potential novel therapeutic targets for PHH.

DOLPHIN-UK CollaboratorsAquilinaKristianMallucciConorChariAswinaswin.chari.18@ucl.ac.ukhttp://orcid.org/0000-0002-5187-140XMedirattaSaniyasaniya.mediratta@gmail.comSivakumarGnanamurthyJamesGregJallohIbrahimKitchenJohnKirkmanMatthew A.de LacyPatriciaLeachPaulMagdumShailendra AshokDawesWilliamLoWilliam B., Chari A, DOLPHIN-UK CollaboratorsAquilinaKristianMallucciConorSivakumarGnanamurthyJamesGregJallohIbrahimKitchenJohnKirkmanMatthew A.de LacyPatriciaLeachPaulMagdumShailendra AshokDawesWilliamLoWilliam B.. A standardised protocol for neuro-endoscopic lavage for post-haemorrhagic ventricular dilatation: A Delphi consensus approach

Neuro-endoscopic lavage (NEL) has shown promise as an emerging procedure for intraventricular haemorrhage (IVH) and post-haemorrhagic ventricular dilatation (PHVD). However, there is considerable variation with regard to the indications, objectives, and surgical technique in NEL. There is currently no randomised trial evidence that supports the use of NEL in the context of PHVD. This study aims to form a consensus on technical variations in the indications and procedural steps of NEL. A mixed-methods modified Delphi consensus process was conducted between consultant paediatric neurosurgeons across the UK. Stages involved literature review, survey, focused online consultation, and iterative revisions until > 80% consensus was achieved. Twelve consultant paediatric neurosurgeons from 10 centres participated. A standardised protocol including indications, a 3-phase operative workflow (pre-ventricular, intraventricular, post-ventricular), and post-operative care was agreed upon by 100% of participants. Case- and surgeon-specific variation was considered and included through delineation of mandatory, optional, and not recommended steps. Expert consensus on a standardised protocol for NEL was achieved, delineating the surgical workflow into three phases such as pre-ventricular, intraventricular, and post-ventricular, each consisting of mandatory, optional, and not recommended steps. The work provides a platform for future trials, training, and implementation of NEL.

Secondary Brain Injury Following Neonatal Intraventricular Hemorrhage: The Role of the Ciliated Ependyma

Intraventricular hemorrhage is recognized as a leading cause of hydrocephalus in the developed world and a key determinant of neurodevelopmental outcome following premature birth. Even in the absence of haemorrhagic infarction or posthaemorrhagic hydrocephalus, there is increasing evidence of neuropsychiatric and neurodevelopmental sequelae. The pathophysiology underlying this injury is thought to be due to a primary destructive and secondary developmental insult, but the exact mechanisms remain elusive and this has resulted in a paucity of therapeutic interventions. The presence of blood within the cerebrospinal fluid results in the loss of the delicate neurohumoral gradient within the developing brain, adversely impacting on the tightly regulated temporal and spatial control of cell proliferation and migration of the neural stem progenitor cells within the subventricular zone. In addition, haemolysis of the erythrocytes, associated with the release of clotting factors and leucocytes into the cerebrospinal (CSF), results in a toxic and inflammatory CSF microenvironment which is harmful to the periventricular tissues, resulting in damage and denudation of the multiciliated ependymal cells which line the choroid plexus and ventricular system. The ependyma plays a critical role in the developing brain and beyond, acting as both a protector and gatekeeper to the underlying parenchyma, controlling influx and efflux across the CSF to brain interstitial fluid interface. In this review I explore the hypothesis that damage and denudation of the ependymal layer at this critical juncture in the developing brain, seen following IVH, may adversely impact on the brain microenvironment, exposing the underlying periventricular tissues to toxic and inflammatory CSF, further exacerbating disordered activity within the subventricular zone (SVZ). By understanding the impact that intraventricular hemorrhage has on the microenvironment within the CSF, and the consequences that this has on the multiciliated ependymal cells which line the neuraxis, we can begin to develop and test novel therapeutic interventions to mitigate damage and reduce the associated morbidity.

[Modern possibilities of diagnosing lesions of the visual analyzer in perinatal lesions of the central nervous system in full-term and premature infants]

The article provides an overview of current neuro-ophthalmological diagnostic capabilities in patients with perinatal lesions. The main attention is paid to the diagnosis of patients with periventricular leukomalacia and peri- and intraventricular hemorrhages. The most relevant methods of neuro-ophthalmological diagnosis in hypoxic-ischemic CNS lesions are covered. The functions and peculiarities of blood supply of the germinal matrix are described. The importance of the use of optical coherence tomography and visual evoked potential recording in full-term and premature infants with visual pathway and/or visual cortex lesions in brain lesions is discussed. The conclusion emphasizes the need for an interdisciplinary approach in the examination of children with perinatal CNS lesions.