Intracranial hemorrhage may be confined to one anatomicarea of the brain, such as the subdural, subarachnoid, periventricular, intraventricular, intraparenchymal, or cerebellar region. Subdural hemorrhages are seen in association with birth trauma, cephalopelvic disproportion,forceps delivery, large for gestational age infants, skull fractures, and postnatal head trauma. The subdural hematomadoes not always cause symptoms immediately after birth;with time, however, the RBCs undergo hemolysis and wateris drawn into the hemorrhage because of the high oncoticpressure of protein, resulting in an expanding symptomaticlesion. Anemia, vomiting, seizures, and macrocephaly mayoccur in an infant who is 1 to 2 months of age and has asubdural hematoma. Child abuse in this situation should be suspected and appropriate diagnostic evaluation undertaken to identify other possible signs of skeletal, ocular, or soft tissue injury. Occasionally, a massive subdural hemorrhage in the neonatal period is caused by rupture of thevein of Galen or by an inherited coagulation disorder, suchas hemophilia. Infants with these conditions exhibit shock,seizures, and coma. The treatment of all symptomatic subdural hematomas is surgical evacuation.
Subarachnoid hemorrhages may be spontaneous, associated with hypoxia, or caused by bleeding from a cerebral arteriovenous malformation. Seizures are a common presenting manifestation, and the prognosis depends on the underlying injury. Treatment is directed at the seizure and the rare occurrence of posthemorrhagic hydrocephalus.
Periventricular hemorrhage and IVH are common in very low birth weight infants; the risk decreases with increasing gestational age. Fifty percent of infants weighing less than 1500 g have evidence of intracranial bleeding.The pathogenesis for these hemorrhages is unknown (theyusually are not caused by coagulation disorders), but theinitial site of bleeding may be the weak blood vessels in theperiventricular germinal matrix. The vessels in this areahave poor structural support. These vessels may rupture and hemorrhage because of passive changes in cerebralblood flow occurring with the variations of blood pressurethat sick premature infants often exhibit (failure of autoregulation). In some sick infants, these blood pressure variations are the only identifiable etiologic factors. In others,the disorders that may cause the elevation or depression ofblood pressure or that interfere with venous return fromthe head (venous stasis) increase the risk of IVH; these disorders include asphyxia, pneumothorax, mechanical ventilation, hypercapnia, hypoxemia, prolonged labor, breechdelivery, patent ductus arteriosus, heart failure, and therapywith hypertonic solutions such as sodium bicarbonate.
Most periventricular hemorrhages and IVHs occur in the first 3 days of life. It is unusual for IVH to occur after day 5 of life. The clinical manifestations of IVH include seizures, apnea, bradycardia, lethargy, coma, hypotension, metabolic acidosis, anemia not corrected by blood transfusion, bulging fontanelle, and cutaneous mottling. Many infants with small hemorrhages (grade 1 or 2) are asymptomatic; infants with larger hemorrhages (grade 4) often have a catastrophic event that rapidly progresses to shock and coma.