Germinal matrix hemorrhage

Germinal matrix hemorrhage is a bleeding into the subependymal germinal matrix with or without subsequent rupture into the lateral ventricle.

Pathophysiology

The germinal matrix is the site of proliferating neuronal and glial precursors in the developing brain, which is located above the caudate nucleus, in the floor of the lateral ventricle, and caudothalamic groove. The germinal matrix contains a rich network of fragile thin-walled blood vessels. Hence the microcirculation in this particular area is extremely sensitive to hypoxia and changes in perfusion pressure. It is most frequent before 35 weeks gestation and is typically seen in very low birth-weight (<1500g) premature infants, because they lack the ability for auto regulation of cerebral blood flow. Consequently, increased arterial blood pressure in these blood vessels leads to rupture and hemorrhage into germinal matrix.

Clinical features

This may lead to various neurological sequelae including presentation with cerebral palsy, mental retardation and seizures.

Grades

Four grades are distinguished (by imaging or histology):

• grade I - hemorrhage is confined to the germinal matrix
• grade II - intraventricular hemorrhage without ventricular dilatation
• grade III - intraventricular hemorrhage with ventricular dilatation
• grade IV - intraventricular rupture and hemorrhage into the surrounding white matter

Treatment

Antenatal corticosteroids have a role in reducing incidence of germinal matrix hemorrhage in premature infants.

See also

• Ganglionic eminence, a part of the germinal matrix

References

• Enzmann D, Murphy-Irwin K, Stevenson D, Ariagno R, Barton J, Sunshine P (1985). "The natural history of subependymal germinal matrix hemorrhage". Am J Perinatol. 2 (2): 123–33. doi:10.1055/s-2007-999929. PMID 3913430. 
• Papile LA, Burstein J,Burstein R, Koffler H. Incidence and evolution of subependymal and intraventricular hemorrhage: A study of infants withbirth weight less than 1,500 gm. J Pediatr 1978;92:529-34.
• Alan Leviton, Karl C. Kuban, Linda Van Marter, Marcello Pagano, and Elizabeth N. Allred. Antenatal Corticosteroids Appear to Reduce the Risk of Postnatal Germinal Matrix Hemorrhage in Intubated Low Birth Weight Newborns Pediatrics, Jun 1993; 91: 1083 - 1088.