pediatrics
Birth Injuries
Intracranial Hemorrhage in Neonates
Hemorrhage in or around the brain can occur in any neonate but is particularly common among those born prematurely; about 25% of preterm infants<1500 g have intracranial hemorrhage. Major causes of intracranial hemorrhageinclude Hypoxia-ischemia Variations in blood pressure Hypoperfusion with reperfusion Abnormal pressures exerted on the head during labor The presence of the germinal matrix (a mass of embryonic cells lying over the caudate nucleus on the lateral wall of the lateral ventricles that is vulnerable to hemorrhage) makes intraventricular hemorrhage more likely in preterm infants. Risk of any intracranial hemorrhage also is increased by hematologic disorders (eg, Vitamin K Deficiency , Hemorrhage can occur in several central nervous system (CNS) spaces. Small hemorrhages in the subarachnoid space, falx, and tentorium are frequent incidental findings at autopsy of neonates who have died of non-CNS causes. Larger hemorrhages in the subarachnoid or subdural space, brain parenchyma, or ventricles are less common but more serious. Intracranial hemorrhage is suspectedin neonates with Apnea Seizures Lethargy Abnormal neurologic examination Such infants should have a cranial imaging study as part of the initial evaluation. Cranial ultrasonography is risk free, requires no sedation, and can readily identify blood within the ventricles or brain substance. CT is more sensitive than ultrasonography for thin layers of blood in the subarachnoid or subdural spaces and for bony injury, but CT exposes the infant to ionizing radiation. MRI is more sensitive and specific than CT or ultrasonography for intracranial blood and for brain injury but takes longer to produce images than CT and may require the infant to be sedated to limit movement and thereby improve image quality. CT is done to rapidly identify intracranial hemorrhage. Treatment of intracranial hemorrhage depends on the location and severity of the hemorrhage but usually is only supportive, including giving vitamin K if not previously given and managing any underlying coagulation abnormality. In cases of significant hemorrhage (eg, subdural hemorrhage), neurosurgical consultation should be obtained to help identify infants requiring intervention. Epidural hematoma is a collection of blood between the skull and the dura mater. It is rare in neonates but can occur in association with a skull fracture or Cephalhematoma . Infants may present with apnea, seizures, or focal neurologic abnormalities. The fontanelles may be bulging if intracranial pressure is increased. Most epidural hematomas are self-limiting and do not require treatment. If an intervention is required, surgical and nonsurgical options exist. Nonsurgical options are percutaneous epidural tapping or ultrasound-guided needle aspiration. Surgical options include craniotomy, which is reserved for cases that are rapidly progressing or not responsive to other interventions. If identified and treated promptly, neurologic outcomes are good. Intraventricular hemorrhage (IVH) and/or intraparenchymal hemorrhage usually occurs during the first 3 days of life in infants < 1500 grams and/or < 32 weeks of gestational age. These hemorrhages are the most serious types of intracranial bleeding. Hemorrhages occur most often in Preterm Infants , are often bilateral, and usually arise in the germinal matrix. The germinal matrix involutes after 32 weeks of gestation, thus IVH in term infants is rare but does occur. IVH is graded as follows ( IVH and/or intraparenchymal hemorrhage references ): Grade I: Limited to the germinal matrix Grade II: Hemorrhage into the ventricle without dilation Grade III: IVH with dilation of the ventricle Grade IV: Same as grade III plus secondary intraparenchymal hemorrhage Most bleeding episodes are subependymal or intraventricular and involve a small amount of blood. In severe hemorrhage (grades III and IV), there may be bleeding into the parenchyma with large amounts of blood in the cisterna magna and basal cisterns. Hypoxia-ischemia often precedes intraventricular and subarachnoid bleeding. Hypoxia-ischemia damages the capillary endothelium, impairs cerebral vascular autoregulation (already compromised in the preterm compared to the term infant) ( IVH and/or intraparenchymal hemorrhage references ), and can increase cerebral blood flow and venous pressure, all of which make hemorrhage more likely. Most intraventricular hemorrhages are asymptomatic, but larger hemorrhages and those in infants with associated hydrocephalus may cause apnea, cyanosis, or sudden cardiovascular instability. Treatment for most hemorrhages is supportive. However, infants with progressive hydrocephalus may require cerebrospinal fluid drainage by placement of a subcutaneous ventricular reservoir or shunt. Endoscopic ventriculostomy is increasingly being used to treat hydrocephalus in selected patients. Because many infants will have neurologic deficits, follow-up and referral for early intervention services are important. Prognosis for infants with small IVHs is good. However, infants with a large IVH have a poor prognosis, especially if the hemorrhage extends into the parenchyma. Many infants who survive have residual neurologic deficits. Preterm infants with a history of severe IVH are at risk of developing posthemorrhagic Hydrocephalus and must be monitored closely with physical examinations, head circumference measurements, and cranial ultrasonography as indicated. 1.Papile LA, Burstein J, Burstein R, Koffler H: Incidence and evolution of subependymal and intraventricular hemorrhage: A study of infants with birth weights less than 1,500 gm.J Pediatr92(4):529-534, 1978. doi: 10.1016/s0022-3476(78)80282-0 2.Gilard V, Tebani A, Bekri S, Marret S: Intraventricular Hemorrhage in Very Preterm Infants: A Comprehensive Review.J Clin Med9(8):2447, 2020. doi: 10.3390/jcm9082447 Subarachnoid hemorrhage probably is the most common type of intracranial hemorrhage. It involves bleeding between the arachnoid membrane and the pia mater. Neonates typically present in the second or third day of life with apnea, seizures, lethargy, or an abnormal neurologic examination. Treatment of subarachnoid hemorrhage is supportive with appropriate monitoring to detect Hydrocephalus . The prognosis for subarachnoid hemorrhage is usually good, with no significant long-term sequelae. However, with large hemorrhages, the associated meningeal inflammation may lead to a communicating hydrocephalus as the infant grows. Subdural hemorrhage involves bleeding between the dura and the pia mater. It results from tears in the falx, tentorium, or bridging veins. Small, subdural hemorrhages up to 3 mm in thickness are very common, occurring in close to half of asymptomatic full-term newborns who had MRI at ≤ 72 hours of age. Such hemorrhages are typically benign. Large subdural hemorrhages tend to occur in neonates of primiparas, in large neonates, or after difficult deliveries—conditions that can produce unusual pressures on intracranial vessels. Neonates may present with apnea, seizures, a rapidly enlarging head, an abnormal neurologic examination with hypotonia, a poor Moro reflex, or extensive retinal hemorrhages. Treatment of large subdural hemorrhage is supportive, but neurosurgical drainage of the hematoma may be necessary for rapidly progressing bleeding with compression of vital intracranial structures and worsening clinical and vital signs. The prognosis for large subdural hemorrhage is guarded. 