The clinical presentation and management of 7 neonates with idiopathic cerebral venous thrombosis (CVT) are reported from the Floating Hospital for Infants and Children, New England Medical Center Hospitals, Tufts University School of Medicine, Boston, MA. Unexplained seizures in 3 infants and unexplained lethargy in 4 led to neurological evaluation and the diagnosis of CVT. Follow-up neurological evaluation through 6 months of age showed normal development. Conventional magnetic resonance images indicated more extensive thrombosis than was suggested by cranial CT. MR phase imaging confirmed thrombosis and established absence of blood flow in cerebral veins or sinuses. No infant received treatment with anticoagulants. 
COMMENT. Cerebral venous thrombosis may explain transient neonatal seizures or lethargy in newborn infants and may be diagnosed by MR and MR phase imaging.