Acquired Developmental Defects

Prematurity is most important risk factor for germinal matrix hemorrhage (GMH)

• Affects about 15% of newborns weighing less than 1500 g

• Neonates with birth weight of 500 g to 750 g at highest risk

Incidence declining because of advances in neonatal care

Rare after 35 weeks gestational age

Acute chorioamnionitis is also a risk factor

The causes of GMH are multiple

• Increased arterial blood pressure, venous congestion, hypoxia, trauma with rupture, and hemorrhage of thin-walled germinal matrix vessels

• Local anatomic factors include high vascularity, immature fragile capillary bed with poor stromal support

Respiratory distress, abnormal eye movements, hypotonia, in utero fetal demise

CSF obstruction by intraventricular blood with posthemorrhagic hydrocephalus and “myelination delay”

Various neurologic sequelae: cerebral palsy, mental retardation, seizures, coma

Neurodevelopmental outcome correlates with the grade of GMH and the presence of associated abnormalities

High mortality with extensive intraventricular hemorrhage

• About 75% mortality with grades II and IV intraventricular hemorrhage

Shunting required for post hemorrhagic hydrocephalus

Four grades of GMH by ultrasound, CT, or MRI:

• Grade I: confined to the germinal matrix

• Grade II: extension into the lateral ventricles without ventricular dilatation

• Grade III: ventricular hemorrhage with ventricular dilatation/hydrocephalus

• Grade IV: extension in parenchyma/white matter hemorrhage

Pinpoint to massive periventricular hemorrhages adjacent to the deep cerebral nuclei (especially the caudate nucleus)

Occur commonly at the level of the foramen of Monro

Larger hemorrhages extend into the lateral ventricles

Hydrocephalus when CSF low is obstructed by blood or related gliosis/scarring

Acute GMH:

• Extravasated red cells within GMZ

• Dissection of blood through stroma-poor GMZ followed by intraventricular hemorrhage

• Periventricular hemorrhagic infarction

Chronic sequelae of GMH:

• Cavitation of hemorrhagic necrosis with formation of gliotic cyst(s)

• Hemosiderin-laden macrophages; scarring of ependyma and leptomeninges

• May have associated hyaline membrane disease and respiratory distress syndrome

Hemorrhagic periventricular leukomalacia

Coagulopathy

Trauma