Neuroimaging and functional outcome of neonatal leukomalacia

Leukomalacia is a major cause of neurological impairment in the high-risk newborn. It can be identified during the early postnatal period by means of ultrasound (US) imaging of the brain, through the anterior fontanel. Magnetic resonance imaging (MRI) permits an optimal differentiation of brain tissue and of its abnormalities, without resorting to ionizing radiation or intravenous contrast. It is particularly appropriate for following the evolution of leukomalacia, after fontanel closure. Ninety-five fullterm and preterm infants with cystic and non-cystic leukomalacia, documented by US, were clinically followed-up until at least 12 months of corrected age. Thirty-two had a severe neurological outcome (mainly cerebral palsy, sometimes associated with mental retardation and/or cerebral visual impairment). The prognosis was worse in cystic leukomalacia than in prolonged flare. Electroencephalogram (EEG) carried out in the first 2 weeks of life provided valuable indexes of further outcome, especially for US findings of more uncertain prognosis. MRI was carried out at around 12 months of corrected age, by means of an apparatus operating at 0.5 Tesla. The main categories of abnormalities observed were the following: cystic lesions, enlarged ventricles with irregular outlines, delayed myelination, high intensity areas in the long TR (repetition time) images within the white matter, cortical atrophy. MRI findings correlated well with the results of US imaging and often with motor, cognitive and visual impairments. Nevertheless, clinical features cannot be predicted by neuroimaging alone and a comprehensive approach, including longitudinal functional and electrophysiological testing, is highly recommended.