Spontaneous cerebrospinal fluid leaks originating from multiple skull base defects.

Spontaneous cerebrospinal fluid (CSF) leaks of temporal bone origin are more prevalent than once believed. Twenty-eight of the 61 cases documented in the world literature have been reported since 1992. All but four of these cases involved unilateral defects. The authors have previously reported experiences with 12 cases, with the vast majority of defects localized to the tegmen tympani. These patients also had demonstrated a single area of bone and dural dehiscence. We report two additional cases of spontaneous CSF leak originating from multiple/distant skull base defects. As in previously reported multisite cases, one of our patients demonstrated an elevated opening pressure on lumbar puncture. Significant time intervals existed between leak site presentations, which emphasizes the importance of careful follow-up for treated patients. Potential etiologies and associated factors are also discussed. This patient subset contributes another dimension to the evolving natural history of spontaneous CSF leakage.