The role of brain ultrasonography in diagnostics and prognosis of perinatal cerebral damage

Perinatal brain damage is the most common cause of neurologic impairments in childhood, whereby cerebral dysfunction occurs as the result of interaction of the existing brain damage and compensatory processes of developmental reorganisation (maturation and plasticity). Ultrasonography has in the last 20 years become the modality of choice in the diagnosis and follow-up of structural reorganisation after perinatal brain damage, providing precise imaging of the type, localisation and size of the brain damage. We present the results of the investigation of two prospective ultrasonographic and neurodevelopmental studies carried out with the aim of determining:
1. the incidence, classification and structural reorganisation of perinatal brain damage, in the group of high-risk preterm and term neonates;
2. the predictive value of ultrasonography in the identification of young infants with neurological impairment;
3. to test the hypothesis of more successful recovery after perinatal brain damage of prematures and/or unilateral lesions due to more favourable potential of brain plasticity; The first study comprised a selected group of 137 high-risk neonates (81 preterms and 56 terms), with more than 80% of them having over 3 risk factors (asphyxia, hypoxic-ischemic encephalopathy, perinatal infection, RDS, EPH gestosis etc.). Ultrasonography revealed a high incidence of 70% all the neonates with perinatal brain damage, where by the incidence of peri-intraventricular haemorrhage (PV-IVH) in preterms examined was 77%, with 21% having coexisting and 3% isolated hypoxic-ischemic brain damage. Intraventricular haemorrhage (IVH) was present in 41% high-risk term neonates, accompanied in 6% by hypoxic-ischemic lesions. Structural changes after perinatal brain damage were present in 60 % of children examined, in 44% atrophy of the periventricular parenchyma "ventriculomegaly" (mild, moderate, severe). Cystic changes of brain parenchyma, and /or diffuse atrophy were found in 15% of children examined. Late ultrasonography demonstrated high sensitivitiy, specificity, positive and negative predictive value (89- 100%) in the identification of children with neuromotor impairments by the age of 2 years, whereas in the prediction of later intellectual visual impairment and epilepsy, late ultrasonography has the satisfactory sensitivity and negative predictive value, and a lower specificity and positive predicitive value (20-54%). Preterms suffered much higher incidence of multihandicap (17.2%) than term neonates (3.6%). The subjects of the secound study were 76 high risk neonates (36 preterms and 40 terms) suffering unilateral perinatal brain damage, diagnosed by ultrasonography at neonatal age. Unilateral parenchymal/intraventricular haemorrhage was present in 58% children, accompanied by hypoxic-ischemic lesion in a further 19.8% children examined. Unilateral, isolated hypoxic-ischemic lesions were found in 12% of children , whereas unilateral conatal hydrocephalus and porencephaly were present in an additional 10.5%. The control group of children comprised gestational age matched 70 high risk neonates with identical bilateral brain damage. Neurodevelopmental assessment performed on all the children by the age 2-12 years respectively, demonstrated more a favourable outcome in children with unilateral perinatal brain damage with significantly less incidence of neuromotor impairments, speech and language disorders and epilepsy. ADDH syndrome was more common in children with unilateral brain damage.