VENTRICULAR CHANGES AFTER CLOSED HEAD INJURY

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.

The twenty-four hour pneumoencephalogram: with particular reference to ventricular size a series of 150 patients and a review of the literature

A series of 150 pneumoencephalograms which included 24 h films was reviewed to evaluate previous contradictory reports concerning changes in ventricular size at 24 h and to establish whether it is useful to obtain these follow-up films. In normal patients the changes in the ventricular index one day following the pneumoencephalogram ranged between -4-1 to +6-4% of the initial index. Statistically significant dilatation of the frontal horns of the lateral ventricles was observed in both patients who had dementia and central atrophy, and in those with normal pressure hydrocephalus. This ventricular enlargement was associated with deterioration in neurological status in some cases. Since ventricular enlargement at 24 h occurs in patients both with normal pressure hydrocephalus and with cerebral atrophy with hydrocephalus, it cannot be used to differentiate between these conditions although the most marked changes have been seen in the former. Significant dilatation did not occur in patients without intracranial disease, with cortical atrophy without hydrocephalus, or in a miscellaneous group. In patients with a history of trauma, enlargement at 24 h occurred only when there was some other encephalographic abnormality. The changes in size of the ventricles were not related to the age of the patient, the volume of the injected air, or to the presnece of subdural air. There were other findings on the follow=up radiographs. Cortical atrophy was more clearly demonstrated than on the filling films. Dilatation of the temporal horns, of questionable diagnostic significance, was not infrequently observed 24 h after air injection. The mechanisms of these changes are discussed; no single theory provides a complete explanation.

Cortical atrophy and air encephalography: a clinical and radiological study

Forty-nine patients with radiological evidence of cortical atrophy were followed up five to 10 years after their radiographic examination. The survivors were examined personally. The original radiographs were then reassessed to establish features indicating a good and poor prognosis. Dimensions of the body of the lateral ventricle distinguished good and poor prognosis, whereas the appearance of the cortical surface did not.