The subarachnoid space in congenital obstructive hydrocephalus

✓ The leptomeninges of 52 patients who died with a diagnosis of congenital or early acquired obstructive hydrocephalus were examined microscopically. In each case a well-developed subarachnoid space was present and in no cases were the leptomeninges congenitally absent. Thus, the commonly held belief that the subarachnoid space may fail to develop in congenital obstructive hydrocephalus was not supported by this study. Pathological findings in the leptomeninges were common, however, and were generally related to the following factors: the severity of the hydrocephalus, the duration of the hydrocephalus, the success or failure of surgical management, past infection (both intrauterine and postnatal), and subarachnoid hemorrhage. The type of ventricular obstruction did not seem to be a significant factor. Certain embryological considerations raised by the current findings are discussed.