Objective To describe different patterns of associated brain lesions in preterm and full-term infants with cerebral sinovenous thrombosis (CSVT) and to assess whether these different patterns are related to gestational age at onset.

Design Magnetic resonance scans of all neonates (six preterm, 24 full term) with suspected CSVT, collected over a 7-year period in two neonatal intensive care units, were evaluated to assess patterns of associated brain lesions. Comparisons between the two gestational age groups were made.

Results CSVT was confirmed on magnetic resonance venography in 26 of 30 neonates (six preterm, 20≥36 weeks' gestational age). The straight (85%) and superior sagittal (65%) sinus were most often affected. Several sinuses were involved in 81% of infants. White matter damage affecting the entire periventricular white matter was seen in five of six preterm infants. Intraventricular haemorrhage (IVH) was common in both groups (4/6 preterm, 16/20 full term). Frontal punctate white matter lesions with restricted diffusion (15/20) and thalamic haemorrhage associated with IVH (11/20) were the most frequent lesions in full-term infants. Focal arterial infarction was present in four of 20 full-term infants. Six infants died in the neonatal period (four preterm, two full term). Follow-up MRIs at 3 months in all survivors showed evolution of the lesions with frontal atrophy in 13 of 20 (12 full term) and delayed myelination in seven of 20 (six full term).

Conclusions Preterm and full-term neonates show different patterns of associated brain lesions. Extensive white matter damage is the predominant pattern of injury in the preterm infant, while an IVH associated with a thalamic haemorrhage and punctate white matter lesions are more common in the full-term infant.