Intraparenchymal hemorrhage
This is bleeding into the cerebral tissue and may be a complication of disseminated intravascular coagulopathy (see above), of a central nervous system malformation, of birth asphyxia or of the extension of a subependymal haemorrhage (see below). Sighs include cerebral irritation and convulsions. Diagnosis is usually made by ultra sound examination and computerized tomography (CT) scan. Intraparenchymal haemorrage may be complicated by destruction of cerebral tissue and the formation of porencephalic cysts, and optimism for the monger term must be guarded. Trearment is usually symptomatic and aimed at controlling convulsions and cerebral oedema.
Periventricular-intraventricular haemorrhage
This is the mosr common and serious of all intracranial haemorrhages . It is a common cause of death in pteterm infants of less than 32 weeks' gestation. The infant particularly at risk is one for whom the delivery has been complicated by asphyxia at trauma and who then develops severe respiratory distress requiring ventilatory support.
The stage of brain development in the preterm infant is a crucial factor in the aetiology of the periventricular-intraventricular haemorrhage. The germinal matrix surrounding the ventricles of the premature infant's brain consists of actively dividing cells. The germinal matrix is sometimes called the subenpendymal layer. Between about 24 and 32 weeks' gestation the blood vessels supplying the matrix are very prominent as a large proportion of cerebral blood flows to this vital area. After 32 weeks' gestation the matrix becomes less and less prominent and by term has involuted almost completely.
Bleeding usually occurs from rupture of the very fine capillaries around the germinal matrix giving rise to a per ventricular or subependymal haemorrhage. An intrventicular haemorrhage develops when the subependymal haemorrhage ruptures into the ventricular system. A subependymal haemorrhage can also extend into the cerebral tissue giving rise to a cerebral or intraparenchymal haemorrhage.
Predisposing factors include:
- birth asphyxia trauma
- prematurity
- sevece respiratory distress
- hypoxia or hyperkapnia
