CT of thrombosed arteriovenous malformations in children

Symptomatic intracranial hemorrhage in full-term infants

A retrospective analysis was undertaken in a consecutive series of 33 full-term infants (birth weight > 2500 g and a minimum of 37 weeks gestational age) with symptomatic intracranial hemorrhage (ICH) admitted to a regional neonatal intensive care unit from January 1986 to December 1992. Eleven infants were born in our institution; 17 were male. The estimated local incidence of symptomatic ICH for the inborn population was 4.9/10000 live births, with a regional incidence of 2.7/10000 live births. Twenty-four (72.3%) infants presented with seizures, apnea, or respiratory distress. Five (15.1%) children developed ICH associated with extracorporeal membrane oxygenation, ventriculoperitoneal shunting, and cardiac surgery. There were two deaths (6.1%) associated with a grade IV periventricular hemorrhage (PVH) and cardiac surgery. Nine infants (27.3%) showed PVH, while an additional nine children developed multifocal cortical hemorrhages. Eight infants (24.2%) showed extra-axial ICH, four children (12.1%) sustained lobar hemorrhages, and three children (9.1%) showed ICH associated with prenatal CNS abnormalities. Excluding five children with iatrogenic ICH, coagulopathies occurred in 9 of 28 infants (32.1%) and constituted a major determinant of the development of ICH. Neurosurgical intervention was limited to one infant with massive ICH and one child with hydrocephalus as a late sequela of ICH. Developmental follow-up was complete in 32 children with a mean and median duration of 3.4 years. Full-term infants with ICH associated with risk factors for hypoxic-ischemic injury showed a significantly greater risk of developmental delay compared to infants with uncomplicated ICH.

Lobar hemorrhages in full-term neonates

A chart analysis for a 5-year period through December 1992 identified four full-term neonates with lobar hemorrhage. Prenatal and obstetrical histories were uncomplicated; all infants presented with seizures within 48 h following birth. Perinatal asphyxia and isoimmune thrombocytopenia were associated with lobar hemorrhage in two children. Although computed tomography was sufficient for diagnosis, magnetic resonance evaluation provided assessment of specific cortical injury and the age of the hemorrhage. No infant underwent surgical intervention; three children reached developmental milestones at a mean follow-up of 3.3 years.

Intracranial arteriovenous malformations in infancy and adolescence

Fifteen children and adolescents with intracranial arteriovenous malformations are reviewed and their data analyzed; their ages varied between 1 day and 15 years and there was a slight predominance of males (9 male and 6 female patients). In this series, the arteriovenous malformations appeared clinically as cerebral hemorrhage in 9 cases, epilepsy in 3, mental retardation with epilepsy in 1, subarachnoid hemorrhage in 1, and cardiac insufficiency at birth in the other. The diagnostic procedures used were computerized transmission tomography (CTT) of the cerebrum in 14 cases, cerebral panarteriography in 15, and EEG in 4 cases. Treatment took the form of surgery, radiation therapy, or medication. The last was administered to patients with epilepsy, either as a complement to other modes of treatment or as the only treatment. In all, 4 cases died, 2 for reasons to do with their operations, 1 from a lesion of the brain stem in a hematoma of the cerebellum that had not been surgically treated, and the other from an intraventricular hemorrhage 4 months after surgery. In the last patient, necropsy revealed remnants of the arteriovenous malformation. The overall mortality was thus 26% and the surgical mortality, 12.6%. Of the 11 surviving patients only 3 received anticonvulsant drugs; each of them had a good I.Q. and good marks at school, as did the other 8 survivors.

Angiographically occult arteriovenous malformations

Eight cases of histopathologically proven arteriovenous malformations (AVM's) which were not visualized on angiography are presented. As is typical with these lesions, most of the patients in this series presented with hemorrhage, seizures, or episodic or progressive neurological symptoms suggestive of a neoplasm. The diagnosis of angiographically occult AVM was highly suspected preoperatively in each case based on the combination of computerized tomography (CT) and magnetic resonance (MR) findings. The CT scans in all cases showed moderately hyperdense lesions which enhanced mildly or moderately in a nonhomogeneous pattern with administration of contrast material. The MR image showed one or more bright areas interspersed with areas of low or absent signal peripherally or centrally on both T1- and T2-weighted images. The AVM was totally excised in seven patients and partially excised in one patient, with favorable results in all. The clinical management and differential diagnosis of angiographically occult AVM's are discussed. In patients with a clinical course and radiological studies suggestive of an occult AVM, removal of the lesion, if accessible, should be performed in order to rule out a neoplasm and prevent subsequent hemorrhage and progression of symptoms.