Abstract
Twelve infants with tense anterior fontanels and delayed clearance in RI-cisternography were studied. Neurologically these infants were divided into 3 groups: 4 damaged infants with mental retardation and/or cerebral palsy, with or without epilepsy, 4 infants whose motor development delayed and catched up later, 4 normal infants.
The tense anterior fontanels improved by 6 to 12 months, and its sizes were larger than mean value, more than two standard deviation in six cases. The head circumferences were larger than mean value in seven cases. Setting sun phenomenon, upper gaze palsy or papill edema was not observed.
Subdural taps were done on 3 cases and in two of them only 2 ml of the subdural fluid was obtained. Brain CT scanning was normal in two patients and borderline in three. Seven patients showed slight or moderate atrophy of convexities and intermispheric fissures, and four patients showed slight enlargement of lateral ventricles. Radioisotope cisternography revealed early ventricular reflux in eight patients, and asymmetric activity on the Sylvian cistern in seven. In all cases the effective half time was more than 24 hours.
These examinations excluded the possibility of subdural effusion or hematoma, communicating hydrocephalus and sinus thrombosis. Clinically one and four of our patients were regarded as megaloencephaly and benign intracranial hypertension, respectively.
Malabsorption of cerebrospinal fluid due to the damaged arachnoid villi was considered to be the basic defect in these patients. The pathophysiology was discussed in relation to benign intracranial hypertension or megaloencephaly.
