Ventricular size following head injury: a clinico-radiological study

A retrospective study of the records of 93 patients who had sustained a severe closed head injury was carried out to determine the relationship, if any, between the severity of the injury, the size of the cerebral ventricles and the residual disability. Ventricular size was expressed as a ventricular index. The callosal angle was also measured to see whether this was of value in the recognition of post-traumatic external obstructive hydrocephalus. A normal range of ventricular indices and callosal angles was obtained from a review of the air encephalograms of 56 patients matched for age and sex with the head injury group, and whose air studies were considered to be normal. The findings on the head injury group were subjected to detailed statistical analysis. The study showed that there was no statistically significant relationship between severity of injury, measured by duration of unconsciousness, and ventricular size expressed as a ventricular index. There was a relationship between ventricular size and residual disability as graded in this study. If age was taken into consideration, the relationship between ventricular size and disability was closer. It was not possible to predict residual disability of individual patients from ventricular size alone due to the wide range of values in any disability grade. Failure of air to pass from the basal cisterns over the cerebral convexities is a widely accepted sign of extraventricular obstruction. The shapes of the ventricles, the ventricular index and a callosal angle of 110 degrees or less provided supporting evidence of obstruction in this study. Recognition of an obstructive element in ventricular dilatation following head injury is important, since in a small carefully selected group of patients a ventricular shunting operation may favourably affect recovery.