Punctate White-matter Lesions in the Full-term Newborn: Underlying Aetiology and Outcome

Background: Punctate white matter lesions (PWMLs) are small focal patches of increased signal intensity (SI) on T1- and decreased SI on T2-weighted magnetic resonance imaging (MRI). To date, there have been few reports of PWMLs in term born infants.

Objective: To identify associated diagnoses and factors predictive of clinical outcome in (near) term infants with PWMLs.

Methods: MRI studies and clinical records of (near) term infants, with PWMLs on MRI scans performed in two institutions in the first 28 postnatal days were reviewed. The PWMLs were classified according to their number, pattern and distribution. The medical records were examined to assess the associated diagnoses and determine the neurodevelopmental outcome at >12 months of age. Infants with congenital heart defect(s), those who had neonatal surgery, or those with perinatal arterial ischemic stroke were not eligible for the study.

Results: Forty-two (near) term infants with PWMLs were included. The major clinical association was perinatal asphyxia, present in 19/42 (45%). Ten (24%) had a history of seizures unrelated to asphyxia or a genetic diagnosis. Eleven (26%) had pathological genetic mutations. Other diagnoses, without seizures were identified in 2 (5%). The lesion load of PWMLs was high (>6) in 30/42 (71%). Evidence of irreversible white matter injury was present in 5 infants who had follow-up MRI performed between 18 and 24 months of age, because of clinical concerns. Five infants died and 37 had follow-up at a median age of 24 months. Neurodevelopmental outcome was poorest amongst 6 infants (16%) whose PWMLs occurred in the setting of a genetic disorder.

Conclusion: PWMLs in (near) term infants represent white matter injury that may evolve into gliosis and/or white matter loss. Infants with PWMLs in the setting of a genetic disorder appeared at most risk of a poor outcome.