Cystic Periventricular Leukomalacia in a Twin-to-Twin Transfusion Syndrome: A Case Report

Dr Mohan Swaminatham, MBBs MD DCH, Neonatal Fellow

Dr Mark W Davies MBBS FRACP DCH Senior Neonatal Fellow, Dr F R Betheras, MBBS FRCOG FRACOG DDU, Neonatal Paediatrician and Ultrasonologist, Royal Women's Hospital Melbourne Vic

Indroduction
Periventricular leukomalacia (PVL) is defined as an ischaemic lesion of the brain of the preterm infant, characterized by infarction of the deep white matter surrounding the lateral ventricles. This area represents a typical watershed of vascular supply. PVL is considered the neuro-anatomic basis for motor and sensory impairments such as spastic diplegia quadriplegia, metal retardation and sensory deficits. Early diagnosis and the study of the developmental sequence of PVL can be identified during the early postnatal period by means of ultrasound (US) imaging of the brain through the anterior fontanelle. With the improved resolution provided by 7.5MHz transducers echo-densities and echo-lucencies can be seen more clearly than before. This has allowed epidemiologic studies of white matter damage in the newborn.

The prognostic value of cranial ultrasound scans has been established for parenchymal lesions. Cystic PVL is known to occur in 5 to 15% of premature infants born at less than 32 weeks gestation and/or less than 1500 grams birth weight. Bilateral extensive cystic PVL denotes an extensive damage to white matter resulting in poor neuro-developmental outcome. The incidence of cerebral palsy in infants with extensive echo lucent parenchymal lesions (cystic PVL) is 60 to 80%. There are multiple risk factors for cystic PVL including premature rupture of membranes, chorioamnionitis, fetal distress, chronic placental infarction, twin to twin transfusion syndrome and disturbance of umbilical blood flow.

We report a case of severe bilateral cystic PVL in the first of a pair of monochromic twins, with serial cranial ultrasound scans. This twin had multiple risk factors known to contribute to the occurrence of cystic PVL as well as probable systemic candidal infection. The usefulness of the cranial ultrasound scans in determining the etiology of severe PVL and following its progress is demonstrated.