Spontaneous cerebrospinal fluid fistula through the clivus: report of two cases.

There have been no previous reports of a spontaneous cerebrospinal fluid fistula through the clivus. We present two such cases, describe their management, and propose a physiopathological explanation. The pulsating effect of the basilar artery in Patient 1 and brisk increases in intracranial pressure through repeated Valsalva maneuvers, acting on a congenitally thin bone in Patient 2, seem to be the plausible causes for the clival leakage.