Pathophysiological Considerations of Subdural Fluid Collection in Childhood

Summary

In childhood, subdural fluid collection often affects the developing brain, but the clinical significance of various states of hydrocephalus is imperfectly understood. This study consists of 61 patients under three years of age who had subdural fluid collection. The subjects were classified as follows: Group A (posttraumatic) 41 cases, Group B (unknown origin) 12 cases, Group C (complicated with cerebral dysgenesis) 8 cases. Subdural fluid pressure was high (more than 180 mmH₂O) in Group A. Continued low or normal pressure was observed in 10 out of 19 cases from Groups B and C. Ventricular reflux and delayed clearance of metrizamide on computed tomography (CT)-cisternography was seen in 11 out of 15 cases in Groups B and C. In 8 of the 61 cases two-space communication, including late filling of the subdural space with contrast medium, was observed. Magnetic resonance imaging (MRI) and CT scans showed enlarged ventricles and subdural spaces with a sulcal pattern in most cases in Group B. The prognosis varied significantly, and severe brain dysfunction was common in Group B. This may have been due to the prolonged suppression of the brain by the large amounts of subdural fluid retained for more than three months, and to brain anomalies such as holoprosencephaly. We concluded that determination of subdural fluid pressure was significant for estimating the degree of brain damage with craniocerebral disproportion and for providing information for therapeutic purposes. The pathophysiological condition of hydrocephalus and brain atrophy accompanied by subdural fluid collection is discussed in detail.