Intracranial haemorrhage within the first two years of life

Background. Spontaneous intracranial haemorrhage is not common in infants, with differences from adults in both aetiology and severity. The infantile CNS is more vulnerable because of incomplete hydrovenous maturation. We ana lyzed infantile intracranial haemorrhage mainly caused by structural brain lesions and discuss specific aetiologies with regard to haemodynamic charac teristics. Subjects and Methods. We reviewed 20 infants less than 2 years of age from a total of 328 neonates and infants with intracranial vascular lesions seen in our institution since 1985. Associated or causative lesions were arteri ovenous malformation (AVM) in 6, dural sinus malformation (DSM) in 4, arter iovenous fistula (AVF) in 3, aneurysm in 2, developmental venous anomaly (D VA) in 1, vein of Galen malformation (VGAM) in 1, and others in 3. The loca tions of haematomas were intracerebral (ICH) in 8, combined ICH and intrave ntricular haemorrhage (IVH) in 5, IVH alone in 5, subarachnoid haemorrhage (SAH) in 1, and combined SDH and ICH in 1. Findings. Three patterns of haemorrhage were noted in high-flow vascular le sions such as AVM or AVF (n = 9); haemorrhage at the site of nidus or fistu la corresponding to nidal pseudoaneurysm in 4, regional venous hypertension with pial venous reflux in 31 global venous infarction causing multifocal haemorrhage in distant brain areas in 2. Aneurysmal bleeds were caused by d issecting aneurysms at the level of dural penetration of cranial vessels. O ne infant had haemorrhage near a DVA without evidence of cavernous malforma tion suggesting the possibility of venous ischaemia. IVH was associated wit h shunt operations in 4 infants with DSM, and SDH followed by ICH in a infa nt with VGAM. Interpretation. Spontaneous intracranial haemorrhage in infants and neonate s is rare; it is associated with specific lesions which show some differenc es from their adult counterparts. The vein-related causes of hemorrhage are largely the pathophysiologic characteristics in this age group. Absence of hemorrhage in VGAM is remarkable in addition to occurrence of most hemorrh ages after shunting.