Optic nerve decompression. A clinical pathologic study

Decompression of the perioptic meninges for intractable chronic papilledema was done in a patient with a right parietal temporal glioblastoma multiforme. The patient died 39 days postoperatively. Histologic study of the optic nerves indicated fistulas in the dura compatible with cerebrospinal fluid (CSF) egress and maintenance of a normal subarachnoid space around the nerve. Two additional patients with unilateral optic nerve decompression producing bilateral resolution of papilledema were studied. We contend that egress of CSF was the principle mode of action in these three cases. How long the dural fistula remains patent is unknown. Reports in the literature show considerable variation in the effects of optic nerve decompression. Anatomic variation of the intracanalicular subarachnoid space together with differences in underlying pathologic condition, surgical technique, and patient response may explain discrepancies among the results reported.