Department of Pathology, University of Oklahoma Health Sciences Center

NeuroTest Sample Question #34 Next question Previous question

Answer: 1 and 3, i.e. B  (The diagnosis is germinal matrix hemorrhage. It is most common in premature infants with 25 to 30 weeks of gestation and the source of hemorrhage is from the germinal matrix.) Level of difficulty: 3 NeuroTest NeuroLearn NeuroHelp

Discussion: 

• Pathology of the case: This is an immature fetal brain. The salient pathologic change is a large hematoma that occupies the right side of the lateral ventricles. Some small hemorrhages (Ú) are also present in subependymal areas (corresponding to the germinal matrix microscopically).
• Age: Periventricular hemorrhage in the germinal matrix is most common in premature babies (22- 30 weeks). Lesions in the white matter (periventricular leukomalacia) are seen in premature babies after 28 weeks of gestations. Hemorrhage from the choroid plexus is more commonly seen in term babies.
• Body weight: Intraventricular hemorrhages among infants weighing <1500 g and who come to necrospy ranges from 23 to 75%. The frequency drops dramatically to 8% in babies weighing >2000g.
• Etiology: By the 18th to 20th week of gestation, the neocortical ventricular wall is lined by a prominent hypercellular well-vascularized zone known as the germinal matrix. This germinal zone is composed of undifferentiated, differentiating and migrating cells, radial glial fibers, polymorphous astrocytes, and thin-walled blood vessels. The germinal cells have very little structural support and the vessels are very fragile. A lot of angiogenesis and vessel remodeling is going on during this period and this may be the reason why this area is so susceptible to hemorrhage in younger premature infants. The control of blood pressure in the brain is not well developed in these infants. The hemorrhage is usually resulted of damage of the vessel wall. The mechanism may be damage of the endothelial cells by acidosis secondary to hypoxia. Birth injury seems to play a role as one-third of cases have difficult deliveries due to forceps rotations and breech presentation.

• Papile’s classification: [Papile LA et al., 1978]

• Grade I:   Subependymal hemorrhage

• Grade II:    Intraventricular hemorrhage.

• Grade III:   Intraventricular hemorhage with ventricular dilation

• Grade IV:  Intraventricular hemorrhage with venticular dilation and parenchymal extension.

• Locations: The most common site is the periventricular matrix zone located between the caudate nucleus and thalamus at the level of or slightly posterior to the foramina of Monro. The next common site is the occipital lobe. The least common site is the temporal horn of lateral ventricle. Hemorrhage may originate over the head of the caudate nucleu. SOme of the smaller hemorrhage may be confined to the germinal matrix without rupture into the ventricle. In these cases, the hemorrhage may be clinically asymptomatic.

Comment: KarMing-Fung@ouhsc.edu