LARGE HEADS AND VENTRICLES IN INFANTS

Abstract

An infant with a large head usually has hydrocephalus or subdural fluid collections. Clinical evidence of other causes of an infantile large head (such as megalencephaly) may be lacking at this early age and computerized axial tomography, angiography, and possible pneumoencephalography must assist in defining the cause. 1. Large ventricles in an infant with an associated large head are a result of hydrocephalus. 2. Large ventricles in a normal or small-sized head are a result of brain atrophy. 3. Common causes of infantile intraventricular obstructive hydrocephalus are: aqueduct stenosis associated with the Chiari malformation; prenatal or postnatal intracerebral hemorrhage; or infection with ventriculitis with aqueduct stenosis. 4. Infantile extraventricular obstructive hydrocephalus is by and large due to obstructive arachnoditis after intracranial infection or hemorrhage. Many infants have obstruction within the subarachnoid space with no definite etiology. 5. Common causes of large ventricles due to cerebral atrophy are intrauterine toxoplasmosis; presumed natal or postnatal anoxia; vascular abnormalities such as arterial occlusions or venous thromboses. 6. Large ventricles due to developmental anomalies of the cerebrum are less common. 7. Ventriculography and angiography, their priority directed by skull roentgenograms, computerized axial tomography, and radionuclide brain scans, are necessary in the investigation of infantile large heads. 8. Pneumoencephalography, often followed by angiography, is used to investigate probable large ventricles in the absence of raised intracranial pressure.