Clinical Aspects of Intraventricular Hemorrhage

Introduction

Intraventricular hemorrhage (IVH) is the presence of blood within the ventricular system including the lateral, third and fourth ventricles. Primary IVH refers to bleeding directly into the ventricular system within the brain, from an intraventricular source or a lesion contiguous to the ventricles. Primary IVH is uncommon. Secondary IVH occurs more frequently (70% of IVH patients) and refers to bleeding extending from the parenchyma or subarachnoid space into the ventricular chambers. Once blood is inside the ventricles, it mixes with the cerebrospinal fluid (CSF) and circulates toward the subarachnoid space, which may result in obstructive hydrocephalus and increased intracranial pressure (ICP) that may be associated with significant morbidity or mortality.

Etiology of Intraventricular Hemorrhage in Infants

Premature infants, especially those born before 32 weeks of gestation and neonates with low birth weight (<1500 g) are at an increased risk of developing IVH compared to full-term infants. The reported rate of IVH is about 20–45% in infant with birth weight less than 1500 g . In premature infants, bleeding occurs in small blood vessels in the subependymal or germinal matrix . The pathogenesis of neonatal germinal matrix IVH is thought to result from hemodynamic changes and alterations in cerebral blood flow coupled with impaired autoregulation resulting in disturbance of perfusion to the delicate cellular structures of the germinal matrix located periventricularly and injury of the fragile blood vessels of the germinal matrix . These changes lead to potential hypoxic ischemic encephalopathy, cell death, and subsequent hemorrhage within this injured brain tissue.

IVH in term infants, toddlers, or children is more frequently associated with trauma. It can also be associated with inherited coagulopathies and vascular malformations.

Several additional risk factors may contribute to an increased risk of IVH including: maternal hypertension during pregnancy, maternal chorioamnionitis, preeclampsia, breech presentation, intrapartum asphyxia, malformed or weak blood vessels in the brain, respiratory distress, mechanical ventilation, blood-clotting abnormalities, shaken baby syndrome, and head injury.

Clinical Presentation of Intraventricular Hemorrhage in Infants

Neonatal IVH usually occurs in the first 72 h after birth. There are several nonspecific signs and symptoms that suggest IVH in infants, full-term infants, toddlers, or children including lethargy and excessive sleep, decreased feeding, nausea, vomiting, weak suckling, apnea, abnormal eye movement, abnormal and persistent crying, hypotonia, and decreased reflexes. More severe presentations may include seizures, cranial nerve abnormalities, bulging fontanelles, hemodynamic instability, and decreased blood count. On the other hand, IVH in infants can be clinically silent, detected only on routine screening.

Grading of Intraventricular Hemorrhage in Infants

In the preterm infants, IVH is often classified into four grades depending on whether the bleeding is confined to the germinal matrix region or if it extends into the ventricles or brain parenchyma ( Table 93.1 ) . Grades I (mild) and II (moderate) are the most common and are often associated with minimal clinical complications. Grades III and IV IVH have a higher-risk morbidity and mortality, including long-term brain injury and neurodevelopmental impairment . One of the main sequelae of grade III or IV IVH is obstructive hydrocephalus requiring intervention.

Diagnosis of Intraventricular Hemorrhage in Infants

Cranial ultrasound is the method of choice for screening, diagnosis, and follow-up of IVH in infants. These infants require repeated imaging to monitor the progression of IVH and potential hydrocephalus.

In older children, noncontrast head CT is used more frequently to diagnose IVH because of the marked limitation of cranial ultrasounds to give detailed imaging of the brain due to closure of skull sutures and thickening of the skull.

Treatment of Intraventricular Hemorrhage in Infants

Several methods have been shown to help in preventing the development of neonatal IVH in preterm infants including antenatal corticosteroids , delayed clamping of the umbilical cord , and prompt resuscitation to avoid hemodynamic instability and metabolic abnormalities that may impair cerebrovascular autoregulation.

Interventions that could decrease the morbidity and mortality of obstructive hydrocephalus associated with IVH include diuretic therapy , repeated lumbar or intraventricular puncture , injection of intraventricular thrombolytics , or a combination of interventions including drainage using external ventricular drain (EVD), irrigation, and fibrinolytic therapy (DRIFT) .

In premature babies with low birth weight (<1500 g), repeated lumbar or mainly ventricular punctures can be employed to decrease the effects of increased ICP secondary to obstructive hydrocephalus. Ventriculoperitoneal shunting is the permanent solution for persistent hydrocephalus secondary to IVH. Shunting can be performed when the infant reaches a reasonable weight (>1.5 kg) .