An intracranial hemorrhage (ICH) can occur in term and preterm infants and is the most common central nervous system (CNS) acute complication of a preterm birth. Types of ICH include subdural hemorrhage, epidural hemorrhage, subarachnoid hemorrhage, intracerebral intraparenchymal hemorrhage, intracerebellar parenchymal hemorrhage, and germinal matrix and intraventricular hemorrhage. An ICH in term infants tends to be extra-axial (subdural, subarachnoid, or subtentorial) and is most related to birth trauma, hypoxic ischemic events, and coagulopathies (eg, thrombophilias or thrombocytopenia). The most common ICH in preterm infants is bleeding from the subependymal germinal matrix and may result in intraventricular or periventricular hemorrhage, either of which can potentially cause hemorrhagic infarctions of the cerebral white matter. With the spread of improved neuroimaging techniques, cerebellar hemorrhage has been detected with increasing frequency, in particular among very immature preterm infants.
A subdural hemorrhage (SDH) is an accumulation of blood between the dura and the arachnoid membrane and involves tears of bridging veins of the subdural compartment (see Figure 7–3). The vascular structures most affected are superficial cerebral veins, infratentorial posterior fossa venous sinuses, the inferior sagittal sinus, and tentorial sinuses and veins (eg, vein of Galen). Blood from an infratentorial hemorrhage in the posterior fossa may accumulate and cause acute symptoms of increased intracranial pressure (ICP) or reside as a hematoma that slowly evolves as a chronic subdural hematoma with increasing fluid accumulation and increasing ICP.
Up to 45% of term newborns may have asymptomatic SDH. Symptomatic SDH usually follows a traumatic delivery of a late preterm or term infant. Only on rare occasions does SDH become clinically critical. Symptomatic SDH occurred in 2.9 per 10,000 spontaneous deliveries, as compared with 8.0 and 9.8 per 10,000 vacuum-assisted and forceps-assisted deliveries, respectively. When both vacuum and forceps are used in delivery, the rate goes up to 21.3 per 10,000.
An SDH is typically related to traumatic birth events involving labor and delivery. Undue pressure on the skull and torsion may produce shear forces resulting in rupture of superficial cerebral bridging veins (carrying blood through the dura mater to the arachnoid mater of the meninges) or tears in the dura or dural reflections (eg, either the falx cerebri or tentorium and associated venous sinuses), causing blood to collect below the dura and superior to the subarachnoid villi. These events are usually found over the cerebrum or within the posterior fossa. Occasionally, skull fractures accompany these findings. Timing of the onset of SDH and clinical findings may be acute or delayed. Clinical signs may be minimal to none, with the SDH self-resolving, or subtle findings of slight irritability or a seemingly hyperalert state may foretell an underlying accumulating SDH with delayed onset of more serious neuropathic circumstances. Latent SDH can lead to ...